CN115612238B - Polystyrene-polyethylene alloy material and preparation method and application thereof - Google Patents

Abstract

The invention discloses a polystyrene-polyethylene alloy material, and a preparation method and application thereof. The alloy material comprises the following components: 30-70 parts of polystyrene resin; 20-60 parts of polyethylene resin; 5-20 parts of compatilizer; 2-8 parts of filler; 0.1-5 parts of nucleating agent; 0-1.5 parts of processing aid; wherein the polyethylene resin is a mixture of low-density polyethylene resin and high-density polyethylene resin in a weight ratio of 1:1-1:4; the weight ratio of the first compatilizer to the second compatilizer is a mixture of 4:1-1:3; the first compatilizer is a styrene-butadiene-styrene block copolymer and/or a hydrogenated styrene-butadiene block copolymer, and the second compatilizer is a polystyrene grafted maleic anhydride copolymer and/or a maleic anhydride grafted polyethylene copolymer. The alloy material has better tensile strength and good solvent resistance.

Description

Polystyrene-polyethylene alloy material and preparation method and application thereof

Technical Field

The invention belongs to the technical field of engineering plastics, and particularly relates to a polystyrene-polyethylene alloy material, and a preparation method and application thereof.

Background

Polystyrene has evolved into a worldwide important polymer commodity, with wide applications in the automotive, appliance, electrical product, furniture, household appliances, telecommunications, electronics, computers, disposables, medicine, packaging, and recreational markets. However, since polystyrene belongs to an amorphous polymer, a molecular chain is in an undisturbed Gaussian coil state, so that a larger free volume exists in the molecular chain, the polystyrene is extremely easy to be corroded by an external solvent, and application risks such as swelling and cracking appear; the polyethylene molecular chain can crystallize under proper conditions to form crystals; the molecular chains are regularly arranged to form a crystal region with compact molecules, and the crystal region has higher solvent erosion resistance; the solvent resistance can be improved by preparing the polystyrene-polyethylene alloy by melt blending.

However, due to the difference of molecular structures, the compatibility of polystyrene and polyethylene is poor, and the processing performance difference is obvious, the prior art CN 104098865A discloses a polystyrene-polyethylene alloy material, and the tensile strength of the alloy material is low, so that the alloy material is extremely easy to deform in the process of molding and reprocessing, and the service performance of the alloy material is influenced. Therefore, there is a need to develop a polystyrene-polyethylene alloy material having higher tensile strength and also good solvent resistance.

Disclosure of Invention

The invention aims to overcome the defect that the polystyrene-polyethylene alloy material in the prior art cannot have better mechanical property and solvent resistance at the same time, and provides a polystyrene-polyethylene alloy material with higher tensile strength and good solvent resistance at the same time.

Another object of the present invention is to provide a method for preparing the polystyrene-polyethylene alloy material.

The invention further aims to provide application of the polystyrene-polyethylene alloy material in preparation of household appliances and automobile materials.

In order to achieve the above object, the present invention is achieved by the following technical scheme:

the polystyrene-polyethylene alloy material comprises the following components in parts by weight:

wherein the polyethylene resin is a mixture of low-density polyethylene resin and high-density polyethylene resin, and the weight ratio of the low-density polyethylene resin to the high-density polyethylene resin is 1:1-1:4; the compatilizer is a mixture of a first compatilizer and a second compatilizer, and the weight ratio of the first compatilizer to the second compatilizer is 4:1-1:3;

the first compatilizer is a styrene-butadiene-styrene block copolymer and/or a hydrogenated styrene-butadiene block copolymer, and the second compatilizer is a polystyrene grafted maleic anhydride copolymer and/or a maleic anhydride grafted polyethylene copolymer.

The inventor surprisingly found that by adopting polystyrene as a base material and compounding low-density polyethylene resin and high-density polyethylene resin, the processability and lower melting temperature of the low-density polyethylene resin, and the high crystallinity and higher melting temperature of the high-density polyethylene resin are better utilized, and the low-density polyethylene resin is firstly melted in the melting blending process to form a melting initiation region, so that the high-density polyethylene resin is promoted to be melted, the melting temperature of the polystyrene-polyethylene alloy is lower, the mechanical property is better, and the solvent resistance of the polystyrene-polyethylene alloy material is improved.

By adopting the compatibility agent for compounding, the compatibility of the system can be effectively improved, and the mechanical property is good when the solvent resistance is good; the first compatilizer contains a polystyrene segment and a butadiene segment, so that the compatibility of polystyrene and polyethylene can be effectively improved, the interface strength is improved, the second compatilizer contains a reactive group, the compatibility of the filler and a matrix can be improved, the filler can migrate to the interface, and the filler can be uniformly distributed in the alloy material; when the weight ratio of the first compatilizer to the second compatilizer is too high, the dispersion is uneven and the processing performance is poor; when the weight ratio of the first compatilizer to the second compatilizer is too low, part of the second compatilizer coating filler can be dispersed in one phase to form micelles, so that stress concentration points can be caused, and the mechanical properties of the alloy material are poor. Therefore, the alloy material has better mechanical property and good solvent resistance by controlling the weight ratio of the compatilizer to the polyethylene resin.

Preferably, the weight ratio of the first compatilizer to the second compatilizer is 3:1-1:2.

Preferably, the weight ratio of the low-density polyethylene resin to the high-density polyethylene resin is 2:3-3:7.

Preferably, the polystyrene resin is a high impact polystyrene.

Preferably, the polystyrene resin has a melt index of 4g/10min to 13g/10min.

Preferably, the polystyrene resin has a melt index measurement standard of ASTM D1238-2010.

Preferably, the polystyrene resin has a melt index measured at 200℃and a measured weight of 5kg.

Preferably, the low-density polyethylene resin has a melt index of 1.5 to 50.0g/10min.

Preferably, the melt index of the low density polyethylene resin is measured as ASTM D1238-2010.

Preferably, the low-density polyethylene resin has a melt index measured at 190℃and a measured weight of 2.16kg.

Preferably, the high-density polyethylene resin has a melt index of 0.1 to 50.0g/10min.

Preferably, the melt index of the high density polyethylene resin is measured as ASTM D1238-2010.

Preferably, the high-density polyethylene resin has a melt index measured at 190℃and a measured weight of 2.16kg.

Preferably, the filler is one or more of calcium carbonate, barium sulfate or talcum powder.

In the present invention, a nucleating agent in the prior art may be selected. Preferably, the nucleating agent is one or more of amide, phosphate and hydrazide compounds.

Specifically, the amide nucleating agent is one or more of polyethylene diamine oxalic acid, polydecamethylene diamine terephthalic acid, polydecamethylene diamine isophthalic acid, polynonamine terephthalic acid or polynonamine isophthalic acid.

Specifically, the phosphate nucleating agent is one or more of sodium phenylphosphinate, sodium 2,2 '-methylene-bis (4, 6-di-tert-butylphenyl) phosphate or bis [2,2' -methylene-bis (4, 6-di-tert-butylphenyl) ] aluminum phosphate.

Specifically, the hydrazide compound is phenyl substituted dihydrazide and/or aliphatic chain dihydrazide.

Preferably, the processing aid is an antioxidant and/or a lubricant.

Preferably, the antioxidant is one or more of hindered phenol antioxidants, phosphite antioxidants or thioester antioxidants.

Specifically, the hindered phenol antioxidant is one or more of N, N' -hexamethylenebis (3, 5-di-tert-butyl-4-hydroxy-benzamide, tetra [ beta- (3, 5-di-tert-butyl-4-hydroxy-phenyl) propionic acid ] pentaerythritol ester, triethylene glycol bis-3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionic acid ester, beta- (4-hydroxy-3, 5-di-tert-butylphenyl) propionic acid N-octadecyl ester or spiro ethylene glycol bis [ beta- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionic acid ester ].

Specifically, the phosphite antioxidant is 2, 4-di-tert-butylphenol and/or bis (2, 6-di-tert-butyl-4-tolyl) pentaerythritol phosphite.

Specifically, the thio-ester antioxidant is one or more of distearyl thiodipropionate, dilauryl thiodipropionate or pentaerythritol dodecyl thiopropyl ester.

In the present invention, a lubricant in the prior art may be used. Preferably, the lubricant is a stearate based lubricant and/or a polyethylene wax.

Specifically, the stearate lubricant can be one or more of calcium stearate, magnesium stearate or zinc stearate.

The preparation method of the polystyrene-polyethylene alloy material comprises the following steps:

s1, drying polystyrene resin, polyethylene resin, a compatilizer, a filler, a nucleating agent and a processing aid, uniformly mixing polystyrene, the compatilizer and part of the processing aid, melt blending, extruding and granulating to obtain a premix master batch;

s2, melting, blending, extruding and granulating the premix master batch obtained in the step S1, polyethylene resin, filler, nucleating agent and the rest of processing aids to obtain the polystyrene-polyethylene alloy material.

Preferably, in step s1, the drying temperature of the drying is 70-90 ℃.

Preferably, in step s1, the drying time of the drying is 3-5 hours.

Preferably, in step S1, the temperature of the melt blending is 180-210 ℃.

Preferably, in step S2, the temperature of the melt blending is 170-190 ℃.

The application of the polystyrene-polyethylene alloy material in preparing refrigerator lining materials and automobile door plate materials is also within the protection scope of the invention.

Compared with the prior art, the invention has the following beneficial effects:

the invention provides a polystyrene-polyethylene alloy material, which adopts polystyrene as a base material, adds compound polyethylene resin and adopts compound compatilizer, and the prepared alloy material has good mechanical property and better solvent resistance. By regulating the weight ratio of the two compatilizers in the compound compatilizer and the weight ratio of the two polyethylene resins in the polyethylene resin, the tensile strength of the alloy material can be improved, the tensile strength of the prepared alloy material is not lower than 28MPa, the solvent resistance is good, and the tensile strength retention rate is not lower than 90%.

Detailed Description

The invention is further illustrated in detail below in connection with specific examples which are provided solely for the purpose of illustration and are not intended to limit the scope of the invention. The test methods used in the following examples are conventional methods unless otherwise specified; the materials, reagents and the like used, unless otherwise specified, are those commercially available.

The raw materials used in each example and comparative example:

polystyrene resin: PSMA5210, yashide chemical company, inc;

polyethylene resin 1: low density polyethylene resin, LDPE 2426H (petrochemical), available from chinese petrochemical company, inc;

polyethylene resin 2: high density polyethylene resin, HDPE HD5502W, available from korean petrochemical company, inc;

polyethylene resin 3: low density polyethylene resin, LDPE L705, available from Sumitomo Chemical co., ltd;

polyethylene resin 4: high density polyethylene resin, HDPE 5000S, available from chinese petroleum and natural gas, inc;

polyethylene resin 5: linear low density polyethylene resin, LLDPE E24065, available from Reliance Industries Limited;

first compatibilizer 1: styrene-butadiene-styrene block copolymer, SBS YH-791E, purchased from chinese petrochemical company, baling petrochemical company;

first compatibilizer 2: hydrogenated styrene-butadiene block copolymer, SEBS G1646V, available from Koteng Polymer Co., ltd;

second compatibilizer 1: polystyrene grafted maleic anhydride copolymer, SZ 23110, available from Polyscope polymers BV;

second compatibilizer 2: maleic anhydride grafted polyethylene copolymer, MC218, available from Ning wave energy, optical New Material technologies Co., ltd;

second compatibilizer 3: ethylene-acrylate-glycidyl methacrylate terpolymer, AX8900, available from alcma;

and (3) filling: calcium carbonate; nucleating agent: phosphate nucleating agents; an antioxidant: hindered phenol antioxidants; and (3) a lubricant: stearate lubricants are commercially available; the same fillers, nucleating agents, antioxidants and lubricants were used in examples 1 to 17 and comparative examples 1 to 6.

In examples and comparative examples, the polystyrene-polyethylene alloy material was prepared by a method comprising the steps of:

s1, placing polystyrene resin, polyethylene resin, compatilizer, filler, nucleating agent and processing aid into an oven at 80 ℃ for drying for 4 hours;

s2, uniformly mixing the polystyrene resin, the toughening agent, the compatilizer and part of processing aids after drying in the step S1, and carrying out first melt blending and first extrusion granulation at 180-210 ℃ to obtain a premix master batch;

s3, carrying out secondary melt blending and secondary extrusion granulation on the pre-mixed master batch obtained in the step S2, the polyethylene resin, the filler, the nucleating agent and the rest of processing aids at 180 ℃ to obtain the polystyrene-polyethylene alloy material.

The component contents of each of the examples and comparative examples are shown in tables 1 to 3.

Table 1 formulas (unit: parts by weight) of polystyrene-polyethylene alloy materials in examples 1 to 8

In the table: x is the weight ratio of the first compatilizer to the second compatilizer; y is the weight ratio of the low-density polyethylene resin to the high-density polyethylene resin.

Table 2 formulas (unit: parts by weight) of polystyrene-polyethylene alloy materials in examples 9 to 17

In the table: x is the weight ratio of the first compatilizer to the second compatilizer; y is the weight ratio of the low-density polyethylene resin to the high-density polyethylene resin.

The component contents of each comparative example are shown in Table 3.

Comparative examples 1 to 6

Table 3 formulas (unit: parts by weight) of polystyrene-polyethylene alloy materials in comparative examples 1 to 6

In the table: x is the weight ratio of the first compatilizer to the second compatilizer; y is the weight ratio of the low-density polyethylene resin to the high-density polyethylene resin.

Performance testing

The properties of the polystyrene-polyethylene alloy materials prepared in the above examples and comparative examples were tested, and specific test items and test methods are as follows:

1. test method

(1) Tensile strength test: according to GB/T1040-2006 test, the stretching rate is 50mm/min, dumbbell type test specimen, type 5A spline: the width of the narrow part is 4mm, and the thickness is 3mm;

(2) Solvent resistance test: drawing a 150 x 10 x 4 tensile spline according to GB/T1040-2006 standard, completely soaking the tensile spline in sunflower seed oil with 5% of fixed deformation, standing for 48 hours, wiping off the sunflower seed oil on the surface, and standing for 24 hours for tensile property test;

(3) Tensile strength retention: tensile strength retention = tensile strength after solvent resistance test/tensile strength x 100% calculated according to the formula.

2. Test results

The measurement results are shown in Table 4.

Table 4 data for each example and comparative example

As can be seen from Table 4, the polystyrene-polyethylene alloy material prepared in the invention has a tensile strength of not less than 28MPa, good solvent resistance and a tensile strength retention of not less than 90%.

As can be seen from comparison of examples 2, examples 5 to 6 and example 11, when the weight ratio of the low-density polyethylene resin to the high-density polyethylene resin is further adjusted to 2:3 to 3:7, the overall properties of the alloy material obtained are better.

As can be seen from the comparison of examples 6 to 10, when the weight ratio of the first compatilizer to the second compatilizer in the compatilizer is further adjusted to be 3:1 to 1:2, the prepared polystyrene-polyethylene alloy material has better comprehensive properties.

From examples 12 to 16, it can be seen that the polystyrene-polyethylene alloy material prepared by compounding different compatilizers and adopting different low-density polyethylene resins and high-density polyethylene resins has equivalent comprehensive properties.

As can be seen from comparative example 1, when only the low-density polyethylene resin is used to improve the solvent resistance of the alloy material, the low-density polyethylene resin has a low molecular crystallinity, which results in a slightly poor solvent resistance of the polystyrene-polyethylene alloy material, and the low-density polyethylene resin has a short molecular chain, a high branching degree, a poor matching property with the polystyrene resin, a poor plasticizing uniformity of the system, and poor mechanical properties.

As can be seen from comparative examples 6 and comparative examples 2 to 3, when the weight ratio of the low-density polyethylene resin to the high-density polyethylene resin is too high, the tensile strength of the prepared alloy material is low, and the alloy material is extremely easy to deform in the process of molding and reprocessing, so that the plate material prepared from the polystyrene-polyethylene alloy material is extremely easy to have defects such as liner folding and deformation in the application process; when the weight ratio of the low-density polyethylene resin to the high-density polyethylene resin is too low, the prepared alloy material has too high rigidity and insufficient ductility, so that risks such as cracking are very easy to occur in the subsequent processing process.

As can be seen from comparing example 6 with comparative examples 4 to 5, when the weight ratio of the first compatibilizer to the second compatibilizer in the compatibilizers is too low, the compatibility of the polystyrene resin and the polyethylene resin is poor, resulting in poor mechanical properties of the material; when the weight ratio of the first compatilizer to the second compatilizer is too high, the filler is unevenly dispersed in the system, so that stress concentration points are easily formed, and the mechanical property of the system is poor.

As can be seen from comparative example 6, the compounding of the linear low-density polyethylene resin and the high-density polyethylene resin resulted in uneven dispersion of the system during plasticizing process due to poor processability of the linear low-density polyethylene resin.

As can be seen from comparative example 7, when the ethylene-acrylic ester-methyl acrylic ester glycidyl ester terpolymer is adopted in the compatilizer for compounding, the compatibility of the compatilizer, polyethylene resin and polystyrene resin is poor, so that the compatilizer is adhered to the surface of the filler to form micelles, and stress concentration points are caused, so that the overall mechanical property is poor, the defects among molecular chains are large, and the solvent resistance is poor.

It is to be understood that the above examples of the present invention are provided by way of illustration only and not by way of limitation of the embodiments of the present invention. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. Any modification, equivalent replacement, improvement, etc. which come within the spirit and principles of the invention are desired to be protected by the following claims.

Claims (10)

1. The polystyrene-polyethylene alloy material comprises the following components in parts by weight:

wherein the polyethylene resin is a mixture of low-density polyethylene resin and high-density polyethylene resin, and the weight ratio of the low-density polyethylene resin to the high-density polyethylene resin is 1:1-1:4; the compatilizer is a mixture of a first compatilizer and a second compatilizer, and the weight ratio of the first compatilizer to the second compatilizer is 4:1-1:3;

the first compatilizer is a styrene-butadiene-styrene block copolymer and/or a hydrogenated styrene-butadiene block copolymer, and the second compatilizer is a polystyrene grafted maleic anhydride copolymer and/or a maleic anhydride grafted polyethylene copolymer.

2. The polystyrene-polyethylene alloy material according to claim 1, wherein the weight ratio of the first compatibilizer to the second compatibilizer is 3:1 to 1:2.

3. The polystyrene-polyethylene alloy material according to claim 1, wherein the weight ratio of the low-density polyethylene resin to the high-density polyethylene resin is 2:3 to 3:7.

4. The polystyrene-polyethylene alloy material according to claim 1, wherein the filler is one or more of calcium carbonate, barium sulfate or talc.

5. The polystyrene-polyethylene alloy material according to claim 1, wherein the nucleating agent is one or more of amides, phosphates and hydrazides.

6. The polystyrene-polyethylene alloy material according to claim 1, wherein the processing aid is an antioxidant and/or a lubricant.

7. The polystyrene-polyethylene alloy material according to claim 6, wherein the antioxidant is one or more of hindered phenol antioxidants, phosphite antioxidants and thio-ester antioxidants.

8. The polystyrene-polyethylene alloy material according to claim 6, wherein the lubricant is a stearate-based lubricant and/or a polyethylene wax.

9. The method for producing a polystyrene-polyethylene alloy material according to any one of claims 1 to 8, comprising the steps of:

s1, drying polystyrene resin, polyethylene resin, a compatilizer, a filler, a nucleating agent and a processing aid, uniformly mixing polystyrene, the compatilizer and part of the processing aid, melt blending, extruding and granulating to obtain a premix master batch;

s2, melting, blending, extruding and granulating the premix master batch obtained in the step S1, polyethylene resin, filler, nucleating agent and the rest of processing aids to obtain the polystyrene-polyethylene alloy material.

10. Use of the polystyrene-polyethylene alloy material according to any one of claims 1 to 8 for preparing lining materials for refrigerators and door panel materials for automobiles.