AU2021105065A4

AU2021105065A4 - Plant-based functional polyester filament and preparation thereof

Info

Publication number: AU2021105065A4
Application number: AU2021105065A
Authority: AU
Inventors: Xiaohua Huang; Xiaoqian HUANG; Jie Liu; Yanming Liu; Yu Liu; Li ZHEN
Original assignee: Bestee Material Tsingtao Co Ltd
Current assignee: Bestee Material Tsingtao Co Ltd
Priority date: 2019-11-06
Filing date: 2021-08-06
Publication date: 2021-09-30
Anticipated expiration: 2028-04-02

Abstract

A plant-based functional polyester filament and a preparation thereof. The plant-based functional polyester filament contains 0.1-1.5% by weight of a plant extract. In the preparation method, a plant-based functional polyester masterbatch is prepared through steps of: heating a polyethylene terephthalate (PET) chip to a molten state; adding an antioxidant and a dispersant to the molten PET followed by stirring; adding a protective agent and the plant extract followed by mixing; adding a modifier followed by uniform mixing; and performing an extrusion granulation process to obtain the plant-based functional polyester masterbatch. The plant-based functional polyester filament provided herein has high mechanical strength of the polyester fiber and anti-mite and antibacterial performances of the plant extract. In addition, the plant-based functional polyester filament has bacteriostatic and deodorization functions, high wear resistance, high elasticity, comfortable hand feeling, pilling resistance and stain resistance.

Description

PLANT-BASED FUNCTIONAL POLYESTER FILAMENT AND PREPARATION THEREOF TECHNICAL FIELD

This application relates to textile technology, and more particularly to a plant-based

functional polyester filament and a preparation thereof.

BACKGROUND

Polyester fiber, as an important synthetic fiber, accounts for more than 60% of the world's

o synthetic fiber production. The polyester fiber is featured with advantages of durability, good

elasticity, resistance to deformation, corrosion resistance and insulation, especially excellent

wrinkle resistance and shape retention. A polyester fabric made of the polyester fiber is

washable, wear-resistant, non-iron and wrinkle-resistant, and is widely applied in outerwear,

home textiles, luggage and tents.

A polyester fiber containing a plant extract theoretically has functions of the plant extract

and the polyester fiber and has a wide range of application prospects. However, there are the

following problems existing in actual production.

When the plant extract is mixed with other functional materials, the properties of the

polyester fiber tend to be changed, such as the elasticity and wear resistance of the polyester

o fiber. In addition, since the functional materials have poor compatibility, the plant extract is

directly added to a molten polyethylene terephthalate (PET) using an existing methods, which

causes agglomeration and uneven dispersion of the plant extract in the PET melt and

high-temperature oxidation. Moreover, the PET melt with the plant extract tends to produce an

expansion zone after the melt is extruded on a spinneret plate, causing that an existing

plant-based functional polyester masterbatch has poor peelability during a spinning process.

The expansion zone will affect the shape of the melt extruded out of a spinneret orifice and

cause the melt to stick to the spinneret plate, thereby affecting the normal production of the

spinning process.

In addition, the polyester fiber, as a type of an artificial synthetic fiber, has shortcomings.

For example, the fabric made of the polyester fiber tends to be pilled, charged with static

electricity and stained with dust after being used for a period of time, which affects the appearance and comfort. So far, there is no a good method in the prior art to solve the shortcomings, thereby affecting the application of the polyester fiber.

Chinese patent application No. 201811438662.1 discloses a polyester fiber containing a

plant extract. The disclosed polyester fiber has the advantages of good natural functionality,

high dry heat shrinkage, high breaking strength, high elastic elongation, greatly improved

wear-resistance, non-toxic, non-inflammability, safety and environmental protection. This

application also solves the problem of poor mechanical strength of the plant-based functional

polyester fiber. Unfortunately, this application fails to solve the shortcomings of the existing

polyester fiber that is easy to be pilled, charged with static electricity and stained with dust.

o Based on the problems described above, it is of great significance to prepare a plant-based

functional polyester fiber with bacteriostatic and deodorization functions, high wear resistance,

high elasticity, comfortable hand feeling, pilling resistance and stain resistance.

SUMMARY

An object of this application is to provide a plant-based functional polyester filament and a

preparation thereof to overcome the above problems.

Technical solutions of the present disclosure are described as follows.

In a first aspect, this application provides a plant-based functional polyester filament,

comprising 0.1-1.5% of a plant extract.

o In an embodiment, the plant extract is a peppermint extract, a valerian extract, a

wormwood extract, a seaweed extract and a combination thereof. In an embodiment, the plant

extract may include any other suitable plant extract, which may not be described herein.

In a second aspect, this application provides a method for preparing the plant-based

functional polyester filament, comprising:

preparing a plant-based functional polyester masterbatch;

wherein the plant-based functional polyester masterbatch is prepared through steps of:

(1) heating a polyethylene terephthalate (PET) chip to a molten state to obtain a molten

PET chip;

(2) adding an antioxidant and a dispersant to the molten PET followed by stirring to obtain

a first mixture;

(3) adding a protective agent and a plant extract to the first mixture followed by mixing to obtain a second mixture; (4) adding a modifier to the second mixture followed by uniform mixing to obtain a third mixture; and (5) subjecting the third mixture to an extrusion granulation to obtain the plant-based functional polyester masterbatch. In an embodiment, a weight ratio of the PET chip to the antioxidant to the dispersant to the protective agent to the modifier is 100: (0.1-0.5): (0.1-0.3): (0.4-0.8): (0.1-0.4). In an embodiment, in step (1), the PET chip is heated to 250-260°C to obtain the molten o PET; in step (2), the stirring is performed at 500-700 r/min for 10-15 min; in step (3), the mixing is performed for 20-40 min; and in step (4), the third mixture is obtained by cooling to 220-230 0 C. In an embodiment, the antioxidant comprises tert-butyl hydroquinone and a zinc powder in a weight ratio of 1: (2-5). In an embodiment, the dispersant comprises sodium tripolyphosphate, ethylene diamine tetraacetic acid (EDTA) and sodium pyrophosphate in a weight ratio of 1: (1-4): (2-4). In an embodiment, the protective agent comprises a nano-carbon powder and a cross-linked porous chitosan microsphere in a weight ratio of 1: (1-4); the cross-linked porous chitosan microsphere is prepared through steps of: o dissolving chitosan in an acetic acid solution with a mass concentration of 2-5%, and removing bubbles by standing to obtain a uniform and transparent chitosan solution, wherein a weight ratio of the chitosan to the acetic acid solution is 1: (95-100); adding an emulsifier to liquid paraffin and nano-silica to obtain an emulsified dispersant by fully stirring, wherein a weight ratio of the liquid paraffin to the nano-silica to the emulsifier is (50-60): (2-5): 1; and dropwise adding the chitosan solution to the emulsified dispersant under stirring; heating a mixture of the chitosan solution and the emulsified dispersant to 40-50 0C followed by uniform mixing and addition of formaldehyde to obtain a reaction mixture; adjusting the reaction mixture to pH 4-5; subjecting the reaction mixture to a reaction at 40-50 0 C for 2-3 h to obtain a product; and after the reaction is completed, subjecting the product to water washing, immersion with a sodium hydroxide solution with a mass concentration of 20-30% and water washing to obtain the cross-linked porous chitosan microsphere, wherein a weight ratio of the chitosan solution to the emulsified dispersant to the formaldehyde is 100: (50-55): (4-8).

In an embodiment, the modifier comprises ethylene-bis-stearamide and silicone oil in a

weight ratio of 1: (3-5).

In an embodiment, the method for preparing the plant-based functional polyester filament

further comprises steps of:

uniformly mixing another PET chip with the plant-based functional polyester masterbatch;

melting a mixture of the another PET chip and the plant-based functional polyester masterbatch

by screw extrusion to obtain a melt product; and extruding the melt product from a spinning

o nozzle to obtain the plant-based functional polyester filament.

Compared to the prior art, the present disclosure has the following beneficial effects.

The plant-based functional polyester filament provided herein has high mechanical

strength of the polyester fiber and anti-mite and antibacterial performances of the plant extract,

In addition, the plant-based functional polyester filament has bacteriostatic and deodorization

functions, high wear resistance, high elasticity, comfortable hand feeling, pilling resistance and

stain resistance. Specifically, a breaking strength of the plant-based functional polyester

filament is 6.8-7.8 cN/dtex, an elasticity modulus is 90-101 cN/dtex and an elongation at break

is 12-18%. The plant-based functional polyester filament is subjected to 2000-times wear test

by using a wear resistant reciprocating testing machine, and the wear loss is less than 0.001 g. A

o mite removal rate is greater than 90%, and antibacterial rates of escherichia coli and

staphylococcus aureus are greater than 98%.

A point-to-point resistance and quantity of electric charge of a fabric prepared from the

plant-based functional polyester filament have reached a standard of Class A anti-static clothing.

In addition, the fabric has pilling resistance and anti-static and anti-dust performances, which

effectively solves the problems of pilling, static electricity and staining with dust of the existing

polyester fiber and expands the application range of the polyester fiber.

With respect to the method for preparing the plant-based functional polyester filament, the

antioxidant is added to prevent the plant extract from discoloration caused by being added to a

high-temperature melt. In addition, the antioxidant is added in the initial stage to make the

molten PET fiber more resistant to oxidation, thereby prevent the plant extract from high-temperature discoloration and appearance of coloring phenomenon when the plant extract is added in the later stage.

dispersant is added to quickly and evenly disperse the plant extract in the PET melt, so as to

avoid local high temperature of the PET melt and formation of a cross-linked three-degree

polymer caused by the agglomerate of the plant extract and prevent the melt from darkening

and change from liquid to colloidal.

nano-carbon powder and the cross-linked porous chitosan microsphere are configured as a

o protective agent. Since the nano-carbon powder and the cross-linked porous chitosan

microsphere have many surface micro-pores, such that the plant extract is coated in the

micro-pores to avoid carbonization of the plant extract. Preferably, the protective agent and the

plant extract are mixed and then added to the melt, such that the plant extract fully enters into

the micro-pores of the protective agent, thereby avoiding the carbonization of the plant extract.

modifier is added to improve the peelability of the melt and prevent the melt from sticking to a

spinneret plate caused by appearance of an expansion zone after the melt is extruded on the

spinneret plate, thereby ensuring the normal production and quality of a spinning process.

o DETAILED DESCRIPTION OF EMBODIMENTS

preparation thereof.

Technical solutions of this application will be further described in detail below with

reference to the embodiments and accompanying drawings.

A plant-based functional polyester filament is provided, containing 0.1-1.5% by weight of

a plant extract. The plant extract is an impurity for a polyester fiber. When a content of the plant

extract is too high, the plant extract has substantially poor dispersibility and tends to

agglomerate during a preparation process of the plant-based functional polyester filament. At

the same time, a melt containing the high-content plant extract has poor peelability and tends to

stick to a spinneret plate, thereby affecting the spinning.

In an embodiment, the plant extract is a peppermint extract, a valerian extract, a lavender extract, a wormwood extract, a chitin extract, a seaweed extract and a combination thereof. In an embodiment, the plant extract may include any other suitable plant extract, which may not be described herein. The present disclosure further provides a method of preparing the plant-based functional polyester filament. In the preparation method, a plant-based functional polyester masterbatch is prepared through the following steps. A polyethylene terephthalate (PET) chip is heated to 250-260°C to obtain a molten PET. o An antioxidant and a dispersant are added to the molten PET followed by stirring at 500-700 r/min for 10-15 min to obtain a first mixture. A protective agent and the plant extract are added to the first mixture followed by mixing for 20-40 min to obtain a second mixture. A modifier is added to the second mixture followed by uniform mixing to obtain a third mixture after the temperature is cooled to 220-230°C. The third mixture is subjected to an extrusion granulation to obtain the plant-based functional polyester masterbatch. A weight ratio of the PET chip to the antioxidant to the dispersant to the protective agent to the plant extract to the modifier is 100: (0.1-0.5): (0.1-0.3): (0.4-0.8): (0.5-5): (0.1-0.4). The plant extract is a peppermint extract, a valerian extract, a lavender extract, a wormwood extract, a seaweed extract and a combination thereof. o The plant extract can be purchased or self-extracted. An extraction method of the plant extract includes water extraction, acid extraction or alcohol extraction. The antioxidant includes tert-butyl hydroquinone and a zinc powder in a weight ratio of 1: (2-5). The antioxidant is configured to prevent the plant extract from discoloration caused by being added to a high-temperature melt. In addition, the antioxidant is added in the initial stage to make the molten PET fiber more resistant to oxidation, thereby prevent the plant extract from high-temperature discoloration and appearance of coloring phenomenon when the plant extract is added in the later stage. The dispersant includes sodium tripolyphosphate, ethylene diamine tetraacetic acid (EDTA) and sodium pyrophosphate in a weight ratio of 1: (1-4): (2-4). The dispersant is configured to quickly and evenly disperse the plant extract in the PET melt, so as to avoid local high temperature of the PET melt and formation of a cross-linked three-degree polymer caused by the agglomerate of the plant extract and prevent the melt from darkening in color and change from liquid to colloidal, thereby protecting mechanical performance of the plant-based functional polyester filament after spinning and uniform color of the plant-based functional polyester filament without dark spots.

The protective agent includes a nano-carbon powder and a cross-linked porous chitosan

microsphere in a weight ratio of 1: (1-4).

The cross-linked porous chitosan microsphere is prepared through the following steps.

Chitosan is dissolved in an acetic acid solution with a mass concentration of 2-5%, and

bubbles are removed by standing to obtain a uniform and transparent chitosan solution, where a

o weight ratio of the chitosan to the acetic acid solution is 1: (95-100).

An emulsifier is added to liquid paraffin and nano-silica to obtain an emulsified dispersant

by fully stirring, where a weight ratio of the liquid paraffin to the nano-silica to the emulsifier is

(50-60): (2-5): 1.

The chitosan solution is dropwise added to the emulsified dispersant under stirring and a

mixture of the chitosan solution and the emulsified dispersant is heated to 40-50°C followed by

uniform mixing and addition of formaldehyde to obtain a reaction mixture. The reaction

mixture is adjusted to pH 4-5. The reaction mixture is subjected to a reaction at 40-50°C for 2-3

h to obtain a product. After the reaction is completed, the product is subjected to water washing,

immersion with a sodium hydroxide solution with a mass concentration of 20-30% and water

o washing to obtain the cross-linked porous chitosan microsphere, where a weight ratio of the

chitosan solution to the emulsified dispersant to the formaldehyde is 100: (50-55): (4-8).

The cross-linked porous chitosan microsphere is prepared using a conventional inverse

crosslinking-emulsion method. Chitosan/acetic acid solution is added to the emulsified

dispersant, and the nano-silica is added and fully dispersed around chitosan molecules by

mechanical stirring, and a cross-linking agent is added. The pH value of the reaction system is

adjusted to enable the chitosan to cross-link into a sphere, and the nano-silica particles are

successfully load on the sphere during the cross-linking process, and uniformly dispersed and

occupy a certain position on the chitosan microsphere. After the cross-linking is completed, the

nano-silica particles are removed with sodium hydroxide solution to obtain the cross-linked

porous chitosan microsphere with evenly dispersed micro-pores, such that the plant extract is filled in the micro-pores, so as to prevent from being carbonized after the plant extract is added to the melt. The protective agent is configured to prevent the carbonization of the plant extract. Since the nano-carbon powder and the cross-linked porous chitosan microsphere have many surface micro-pores, such that the plant extract is coated in the micro-pores to avoid carbonization of the plant extract. In an embodiment, the protective agent and the plant extract are mixed and then added to the melt, such that the plant extract fully enters into the micro-pores of the protective agent, thereby avoiding the carbonization of the plant extract. The modifier includes ethylene-bis-stearamide and silicone oil in a weight ratio of 1: (3-5). o The modifier is added to improve peelability of the melt and prevent the melt from sticking to a spinneret plate caused by appearance of an expansion zone after the melt is extruded on the spinneret plate, thereby ensuring the normal production and quality of a spinning process. A PET chip is uniformly mixed with the plant-based functional polyester masterbatch and then a mixture of the PET chip and the plant-based functional polyester masterbatch is melted by screw extrusion to obtain a melt product. The melt product is extruded from a spinning nozzle to obtain the plant-based functional polyester filament. A diameter of the spinning nozzle is 5-50 m. In an embodiment, a weight ratio of the common PET chip to the plant-based functional polyester masterbatch is (2-50): 1. The blend spinning of the common PET chip and the plant-based functional polyester masterbatch ensures the effective content of the plant o extract the plant extract in the plant-based functional polyester filament, reduces production of the plant-based functional polyester masterbatch and improves the production efficiency. This application will be further described in detail below with reference to the embodiments.

Example 1 This embodiment provided a plant-based functional polyester filament, containing 0.1% by weight of a plant extract.

Example 2 This embodiment provided a plant-based functional polyester filament, containing 1.5% by weight of a plant extract.

Example 3 This embodiment provided a plant-based functional polyester filament, containing 0.5% by weight of a plant extract.

Example 4 This embodiment provided a plant-based functional polyester filament, containing 1.0% by weight of a plant extract.

o Example 5 This embodiment provided a plant-based functional polyester filament, containing 1.2% by weight of a plant extract.

Example 6 This embodiment provided a method of preparing the plant-based functional polyester filament, including the following steps. In the preparation method, a plant-based functional polyester masterbatch was prepared through the following steps. A polyethylene terephthalate (PET) chip was heated to 250-260°C to obtain a molten PET. o An antioxidant and a dispersant were added to the molten PET followed by stirring at 500 r/min for 10 min to obtain a first mixture. A protective agent and the plant extract were added to the first mixture followed by mixing for 20 min to obtain a second mixture. A modifier was added to the second mixture followed by uniform mixing to obtain a third mixture after the temperature was cooled to 230°C. The third mixture was subjected to an extrusion granulation to obtain the plant-based functional polyester masterbatch. A weight ratio of the PET chip to the antioxidant to the dispersant to the protective agent to the plant extract to the modifier was 100: 0.1: 0.1: 0.4: 0.5: 0.1. The antioxidant included tert-butyl hydroquinone and a zinc powder in a weight ratio of 1: 2. The dispersant included sodium tripolyphosphate, ethylene diamine tetraacetic acid (EDTA) and sodium pyrophosphate in a weight ratio of 1: 1: 2.

The protective agent included a nano-carbon powder and a cross-linked porous chitosan

microsphere in a weight ratio of 1: 1.

The cross-linked porous chitosan microsphere was prepared through the following steps.

Chitosan was dissolved in an acetic acid solution with a mass concentration of 2%, and

bubbles were removed by standing to obtain a uniform and transparent chitosan solution, where

a weight ratio of the chitosan to the acetic acid solution was 1: 95.

An emulsifier was added to liquid paraffin and nano-silica to obtain an emulsified

dispersant by fully stirring, where a weight ratio of the liquid paraffin to the nano-silica to the

emulsifier was 50: 2: 1.

o The chitosan solution was dropwise added to the emulsified dispersant under stirring and

then a mixture of the chitosan solution and the emulsified dispersant was heated to 40°C

followed by uniform mixing and addition of formaldehyde to obtain a reaction mixture. The

reaction mixture was adjusted to pH 4. The reaction mixture was subjected to a reaction at 40°C

for 2 h to obtain a product. After the reaction was completed, the product was subjected to

water washing, immersion with a sodium hydroxide solution with a mass concentration of 20%

and water washing to obtain the cross-linked porous chitosan microsphere, where a weight ratio

of the chitosan solution to the emulsified dispersant to the formaldehyde was 100: 50: 4.

The modifier included ethylene-bis-stearamide and silicone oil in a weight ratio of 1: 3.

A PET chip was uniformly mixed the plant-based functional polyester masterbatch and

o then a mixture of the PET chip and the plant-based functional polyester masterbatch was melted

by screw extrusion to obtain a melt product. The melt product was extruded from a spinning

nozzle to obtain the plant-based functional polyester filament containing 0.1% by weight of the

plant extract. A weight ratio of the common PET chip to the plant-based functional polyester

masterbatch was 4: 1.

Example 7

This embodiment provided a method of preparing the plant-based functional polyester

filament, including the following steps.

In the preparation method, a plant-based functional polyester masterbatch was prepared

through the following steps.

A polyethylene terephthalate (PET) chip was heated to 250-260°C to obtain a molten PET.

An antioxidant and a dispersant were added to the molten PET followed by stirring at 700 r/min

for 15 min to obtain a first mixture. A protective agent and the plant extract were added to the

first mixture followed by mixing for 40 min to obtain a second mixture. A modifier was added

to the second mixture followed by uniform mixing to obtain a third mixture after the

temperature was cooled to 220°C. The third mixture was subjected to an extrusion granulation

to obtain the plant-based functional polyester masterbatch.

A weight ratio of the PET chip to the antioxidant to the dispersant to the protective agent to

the plant extract to the modifier was 100: 0.5: 0.3: 0.4: 5: 0.4.

o The antioxidant included tert-butyl hydroquinone and a zinc powder in a weight ratio of 1:

5.

The dispersant included sodium tripolyphosphate, ethylene diamine tetraacetic acid

(EDTA) and sodium pyrophosphate in a weight ratio of 1: 4: 4.

microsphere in a weight ratio of 1: 4.

Chitosan was dissolved in an acetic acid solution with a mass concentration of 5%, and

a weight ratio of the chitosan to the acetic acid solution was 1: 100.

o An emulsifier was added to liquid paraffin and nano-silica to obtain an emulsified

emulsifier was 60: 5: 1.

The chitosan solution was dropwise added to the emulsified dispersant under stirring and

then a mixture of the chitosan solution and the emulsified dispersant was heated to 50°C

reaction mixture was adjusted to pH 5. The reaction mixture was subjected to a reaction at 50°C

for 3 h to obtain a product. After the reaction was completed, the product was subjected to

water washing, immersion with a sodium hydroxide solution with a mass concentration of 30%

of the chitosan solution to the emulsified dispersant to the formaldehyde was 100: 55: 8.

The modifier included ethylene-bis-stearamide and silicone oil in a weight ratio of 1: 5.

then a mixture of the PET chip and the plant-based functional polyester masterbatch was melted

nozzle to obtain the plant-based functional polyester filament containing 1.0% by weight of the

masterbatch was 4: 1.

Example 8

This embodiment provides a method of preparing the plant-based functional polyester

o filament, including the following steps.

through the following steps.

An antioxidant and a dispersant were added to the molten PET followed by stirring at 600 r/min

for 12 min to obtain a first mixture. A protective agent and the plant extract were added to the

first mixture followed by mixing for 30 min to obtain a second mixture. A modifier was added

temperature was cooled to 225°C. The third mixture was subjected to an extrusion granulation

to obtain the plant-based functional polyester masterbatch.

o A weight ratio of the PET chip to the antioxidant to the dispersant to the protective agent to

the plant extract to the modifier was 100: 0.2: 0.2: 0.5: 4.5: 0.2.

The antioxidant included tert-butyl hydroquinone and a zinc powder in a weight ratio of 1:

3. The dispersant included sodium tripolyphosphate, ethylene diamine tetraacetic acid

(EDTA) and sodium pyrophosphate in a weight ratio of 1: 2: 3.

microsphere in a weight ratio of 1: 2.

Chitosan was dissolved in an acetic acid solution with a mass concentration of 3%, and

a weight ratio of the chitosan to the acetic acid solution was 1: 96.

An emulsifier was added to liquid paraffin and nano-silica to obtain an emulsified dispersant by fully stirring, where a weight ratio of the liquid paraffin to the nano-silica to the emulsifier was 56: 4: 1. The chitosan solution was dropwise added to the emulsified dispersant under stirring and then a mixture of the chitosan solution and the emulsified dispersant was heated to 45°C followed by uniform mixing and addition of formaldehyde to obtain a reaction mixture. The reaction mixture was adjusted to pH 4.5. The reaction mixture was subjected to a reaction at 45°C for 2.5 h to obtain a product. After the reaction was completed, the product was subjected to water washing, immersion with a sodium hydroxide solution with a mass concentration of 24% o and water washing to obtain the cross-linked porous chitosan microsphere, where a weight ratio of the chitosan solution to the emulsified dispersant to the formaldehyde was 100: 52: 6. The modifier included ethylene-bis-stearamide and silicone oil in a weight ratio of 1: 4. Another PET chip was uniformly mixed the plant-based functional polyester masterbatch and then a mixture of the PET chip and the plant-based functional polyester masterbatch was melted by screw extrusion to obtain a melt product. The melt product was extruded from a spinning nozzle to obtain the plant-based functional polyester filament containing 1.5% by weight of the plant extract. A weight ratio of the common PET chip to the plant-based functional polyester masterbatch was 2: 1.

o Example 9 This embodiment provides a method of preparing the plant-based functional polyester filament, including the following steps. In the preparation method, a plant-based functional polyester masterbatch was prepared through the following steps. A polyethylene terephthalate (PET) chip was heated to 250-260°C to obtain a molten PET. An antioxidant and a dispersant were added to the molten PET followed by stirring at 550 r/min for 14 min to obtain a first mixture. A protective agent and the plant extract were added to the first mixture followed by mixing for 25 min to obtain a second mixture. A modifier was added to the second mixture followed by uniform mixing to obtain a third mixture after the temperature was cooled to 225°C. The third mixture was subjected to an extrusion granulation to obtain the plant-based functional polyester masterbatch.

the plant extract to the modifier was 100: 0.4: 0.15: 0.5: 4: 0.3.

4.

(EDTA) and sodium pyrophosphate in a weight ratio of 1: 3: 2.5.

microsphere in a weight ratio of 1: 3.

o Chitosan was dissolved in an acetic acid solution with a mass concentration of 4%, and

a weight ratio of the chitosan to the acetic acid solution was 1: 98.

emulsifier was 58: 4: 1.

then a mixture of the chitosan solution and the emulsified dispersant was heated to 48°C

reaction mixture was adjusted to pH 4.5. The reaction mixture was subjected to a reaction at

o 48°C for 2 h to obtain a product. After the reaction was completed, the product was subjected to

water washing, immersion with a sodium hydroxide solution with a mass concentration of 28%

of the chitosan solution to the emulsified dispersant to the formaldehyde was 100: 54: 5.

The modifier included ethylene-bis-stearamide and silicone oil in a weight ratio of 1: 3.5.

Another PET chip was uniformly mixed the plant-based functional polyester masterbatch

and then a mixture of the PET chip and the plant-based functional polyester masterbatch was

melted by screw extrusion to obtain a melt product. The melt product was extruded from a

spinning nozzle to obtain the plant-based functional polyester filament containing 0.5% by

weight of the plant extract. A weight ratio of the common PET chip to the plant-based

functional polyester masterbatch was 7: 1.

The plant extract in the plant-based functional polyester filament prepared in Examples 1-9

is a peppermint extract, a valerian extract, a lavender extract, a wormwood extract, a seaweed

extract and a combination thereof.

Detection indexes of the plant-based functional polyester filament prepared in Examples

6-9 is shown in Table 1. An antibacterial rate is measured with a vibration method referring to

GB/T20944.3-2008 Textiles-Evaluation for antibacterial activity. A mite removal rate is

measured referring to GB/T24253-2009 Textiles-Evaluation for anti-mites activity.

Table 1 Test data of the plant-based functional polyester filament prepared in Examples

6-9 Example 6 Example 7 Example 8 Example 9

Breaking strength 7.8 7.0 6.8 7.5 (cN/dtex)

Elasticity modulus 101 94 90 98 (cN/dtex)

Elongation at break (%) 18 14 12 16

2000-times <0.001 <0.001 <0.001 <0.001 wear loss (g)

Mite removal rate (%) 90.1 95.8 98.4 92.2

Antibacterial rate of

escherichia coli (%)

Antibacterial rate of

staphylococcus aureus 98.2 98.9 99.5 98.6

(0%)

It can be concluded from Table 1 that all indexes of the plant-based functional polyester

filament containing the plant extract are normal and have reached the requirements of the

polyester fiber. Specifically, the plant-based functional polyester filament has suitable breaking

strength, elasticity modulus and elongation at break, respectively 6.8-7.8 cN/dtex, 90-101

cN/dtex and 12-18%. In addition, the plant-based functional polyester filament has high wear

resistance, and the plant-based functional polyester filament is subjected to 2000-times wear

test by using a wear resistant reciprocating testing machine, and the wear loss is less than 0.001 g. Due to the addition of the plant extract, the plant-based functional polyester filament has antibacterial and anti-mite functions, and a mite removal rate is greater than 90%, and antibacterial rates of escherichia coli and staphylococcus aureus are greater than 98%. Comparative examples are designed on the basis of Example 7 in order to compare the effects of the antioxidant, the dispersant, the protective agent and the modifier in the preparation process. Comparative example 1 The method used herein for preparing the plant-based functional polyester filament was basically the same as that in Example 7, except that the antioxidant was not added herein.

Comparative example 2 The method used herein for preparing the plant-based functional polyester filament was basically the same as that in Example 7 except that the dispersant was not added herein.

Comparative example 3 The method used herein for preparing the plant-based functional polyester filament was basically the same as that in Example 7 except that the protective agent was not added herein.

Comparative example 4 o The method used herein for preparing the plant-based functional polyester filament was basically the same as those in Example 7 except that the modifier was not added herein. Test data of the plant-based functional polyester filament prepared in Comparative examples 1-4 are shown in Table 2. Table 2 Test data of the plant-based functional polyester filament prepared in Comparative examples 1-4 Comparative Comparative Comparative Comparative Example 7 example 1 example 2 example 3 example 4

Breaking strength 7.0 7.0 6.8 7.0 7.0 (cN/dtex)

Elasticity modulus 94 93 92 94 94

(cN/dtex)

Elongation at 14 14 12 14 13 break (%)

2000-times <0.001 0.001 0.002 <0.001 <0.001 wear loss (g)

Mite removal rate 95.8 95.0 95.8 75 95.8 (0%)

Antibacterial rate

of escherichiacoli 99.1 99.0 99.1 82 99.0

(0%)

Antibacterial rate

ofstaphylococcus 98.9 98.6 98.9 80 98.9

aureus (%)

Non-uniform,

Degree of coloring Uniform Color with dark Uniform Uniform

spots

It can be concluded from Table 2 that the plant-based functional polyester filament in

Comparative example 1 has similar breaking strength, elasticity modulus, elongation at break

and wear resistant performance as that in Example 7. However, the antioxidant is not added

during the preparation of the plant-based functional polyester filament in Comparative example

1, causing high-temperature discolouration of the plant extract and appearance of coloring

phenomenon and reducing the antibacterial performance of the plant extract.

The plant-based functional polyester filament in Comparative example 2 has the same

anti-mite and antibacterial performances as that in Example 7. However, the dispersant is not

added during the preparation of the plant-based functional polyester filament in Comparative

example 2, resulting in local high temperature of the PET melt and formation of a cross-linked

three-degree polymer due to agglomerate of the plant extract, such that the melt darkens in

color and changes from liquid to colloidal, thereby affecting mechanical performance of the plant-based functional polyester filament after spinning and causing uneven color of the plant-based functional polyester filament and dark spots. The plant-based functional polyester filament in Comparative example 3 has similar breaking strength, elasticity modulus, elongation at break and wear resistant performance as s that in Example 7. In other words, the mechanical performance of the plant-based functional polyester filament is not affected. However, the protective agent is not added during the preparation of the plant-based functional polyester filament in Comparative example 3, causing that the plant extract is carbonized and fails to be fully and smoothly added to the PET melt, thereby reducing anti-mite and antibacterial performances of the plant-based functional polyester filament after spinning. The plant-based functional polyester filament in Comparative example 4 has similar test data as that in Example 7. Since the melt has poor peelability and tends to stick to a spinneret plate, it is necessary to continuously spray silicone oil on the spinneret plate to in order for smooth spinning. However, the spraying amount of the silicone oil is not easy to control. The spraying amount of the silicone oil is too large to dirty the spinneret plate, affecting the quality of the plant-based functional polyester filament, and the spraying amount of the silicone oil is too small to make the melt stick to the spinneret plate, thereby repeatedly stopping the spinning process for cleaning the spinneret plate. The plant-based functional polyester filaments prepared in Examples 6-9 are subjected to o 2000-times wear test by using a wear resistant reciprocating testing machine, and the wear loss is less than 0.001 g, which indicates the plant-based functional polyester filaments prepared in Examples 6-9 have excellent wear-resistance performance. At the same time, the electrostatic phenomenon may not occur during the test process. The plant-based functional polyester filaments prepared in Examples 6-9 are respectively spun into a fabric using an existing method, and the anti-static performance is also studied according to a standard of GB 12014-2009 static protective clothing. Data of a point-to-point resistance and quantity of electric charge of the fabric are shown in Table 3.

Table 3 Anti-static test results of the fabric made of the plant-based functional polyester filaments prepared in Examples 6-9 Quantity of electric charge Point-to-point resistance (Q) (piC/m 2

) Example 6 3.5 x 106 0.09

Example 7 5.0 x 106 0.14

Example 8 5.2x 106 0.18

Example 9 4.6x 106 0.12

It can be concluded from Table 3 that the fabric made of the plant-based functional polyester filaments prepared in Examples 6-9 has the point-to-point resistance and quantity of electric charge reached a standard of Class A anti-static clothing. In addition, the fabric has pilling resistance and anti-static and anti-dust performances.

Claims

CLAIMS What is claimed is:

1. A plant-based functional polyester filament, comprising 0.1-1.5% by weight of a plant

extract.

2. A method for preparing a plant-based functional polyester filament, comprising:

preparing a plant-based functional polyester masterbatch;

PET chip;

a first mixture;

(3) adding a protective agent and a plant extract to the first mixture followed by mixing to

obtain a second mixture;

(4) adding a modifier to the second mixture followed by uniform mixing to obtain a third

mixture; and

(5) subjecting the third mixture to an extrusion granulation to obtain the plant-based

functional polyester masterbatch.

3. The method according to claim 2, characterized in that a weight ratio of the PET chip to

the antioxidant to the dispersant to the protective agent to the modifier is 100: (0.1-0.5):

(0.1-0.3): (0.4-0.8): (0.1-0.4).

4. The method according to claim 2, characterized in that in step (1), the PET chip is

heated to 250-260°C to obtain the molten PET; in step (2), the stirring is performed at 500-700

r/min for 10-15 min; in step (3), the mixing is performed for 20-40 min; and in step (4), the

third mixture is obtained by cooling to 220-230°C.

5. The method according to claim 2, characterized in that the antioxidant comprises

tert-butyl hydroquinone and a zinc powder in a weight ratio of 1: (2-5).

6. The method according to claim 2, characterized in that the dispersant comprises sodium

tripolyphosphate, ethylenediamine tetraacetic acid (EDTA) and sodium pyrophosphate in a

weight ratio of 1: (1-4): (2-4).

7. The method according to claim 2, characterized in that the protective agent comprises a

nano-carbon powder and a cross-linked porous chitosan microsphere in a weight ratio of 1:

(1-4); the cross-linked porous chitosan microsphere is prepared through steps of:

dissolving chitosan in an acetic acid solution with a mass concentration of 2-5%, and

removing bubbles by standing to obtain a uniform and transparent chitosan solution, wherein a

weight ratio of the chitosan to the acetic acid solution is 1: (95-100);

adding an emulsifier to liquid paraffin and nano-silica to obtain an emulsified dispersant

by fully stirring, wherein a weight ratio of the liquid paraffin to the nano-silica to the emulsifier

is (50-60): (2-5): 1; and

dropwise adding the chitosan solution to the emulsified dispersant under stirring; heating a

mixture of the chitosan solution and the emulsified dispersant to 40-50°C followed by

uniform mixing and addition of formaldehyde to obtain a reaction mixture; adjusting the

reaction mixture to pH 4-5; subjecting the reaction mixture to a reaction at 40-50°C for 2-3 h to

obtain a product; and after the reaction is completed, subjecting the product to water washing,

washing to obtain the cross-linked porous chitosan microsphere, wherein a weight ratio of the

8. The method according to claim 2, characterized in that the modifier comprises ethylene

bis-stearamide and silicone oil in a weight ratio of 1: (3-5).

9. The method according to claim 2, further comprising:

melting a mixture of the another PET chip and the plant-based functional polyester masterbatch by screw extrusion to obtain a melt product; and extruding the melt product from a spinning nozzle to obtain the plant-based functional polyester filament.