CN113336986A - Preparation method of oriented gamma-phase PVDF/CTAB composite film - Google Patents

Preparation method of oriented gamma-phase PVDF/CTAB composite film Download PDF

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CN113336986A
CN113336986A CN202110620855.4A CN202110620855A CN113336986A CN 113336986 A CN113336986 A CN 113336986A CN 202110620855 A CN202110620855 A CN 202110620855A CN 113336986 A CN113336986 A CN 113336986A
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pvdf
ctab
composite film
phase
stretching
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王海军
刘坤
刘子雄
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Shaanxi University of Science and Technology
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Shaanxi University of Science and Technology
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    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08JWORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J5/00Manufacture of articles or shaped materials containing macromolecular substances
    • C08J5/18Manufacture of films or sheets
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08JWORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2327/00Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers
    • C08J2327/02Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment
    • C08J2327/12Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment containing fluorine atoms
    • C08J2327/16Homopolymers or copolymers of vinylidene fluoride
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08KUse of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K5/00Use of organic ingredients
    • C08K5/16Nitrogen-containing compounds
    • C08K5/17Amines; Quaternary ammonium compounds
    • C08K5/19Quaternary ammonium compounds

Abstract

A preparation method of an oriented gamma-phase PVDF/CTAB composite film adopts Cetyl Trimethyl Ammonium Bromide (CTAB) to improve the phase change capability of polyvinylidene fluoride (PVDF), increases the nucleation rate of the gamma-phase of the polyvinylidene fluoride under the action of low-temperature nucleation and high-temperature crystallization, accelerates the growth rate of the gamma-phase, obtains the oriented gamma-phase PVDF under the action of high-temperature stretching, and can quickly prepare the oriented gamma-phase PVDF/CTAB composite film; detection and comparison find that the stretched PVDF/CTAB composite film contains a large amount of oriented gamma-phase PVDF; the invention has simple preparation process and convenient operation, has excellent performances of high temperature resistance, corrosion resistance, piezoelectricity and ferroelectricity, and has potential application value in the aspects of capacitors, sensors, information storage, electronic devices and high temperature resistant thermosensitive materials as a high temperature resistant functional polymer material.

Description

Preparation method of oriented gamma-phase PVDF/CTAB composite film
The invention belongs to the technical field of preparation of polymer films, and particularly relates to a preparation method of an oriented gamma-phase PVDF/CTAB composite film.
Background
The functionalization of polymer film materials has been receiving wide attention, and polyvinylidene fluoride (PVDF) is a polycrystalline semi-crystalline polymer, and the most common crystal forms are three, namely, alpha, beta and gamma; the alpha-phase polyvinylidene fluoride has excellent mechanical properties and can be used in electronics, chemical engineering, solar devices and the like; the beta-phase polyvinylidene fluoride has good piezoelectric and ferroelectric effects and is widely applied to transducer devices in various fields, such as pressure sensitive devices, humidity sensitive devices and the like; the gamma phase has ferroelectricity and piezoelectricity, the Curie temperature of the gamma phase is higher than that of the beta phase, and the gamma phase is an excellent high-temperature-resistant flexible piezoelectric material. Orientation is an important method to improve the properties of materials. The prior art generally adopts a melt drawing method for preparing polyvinylidene fluoride, and has the defect of low gamma phase content.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention aims to provide a preparation method of an oriented gamma-phase PVDF/CTAB composite film, which adopts Cetyl Trimethyl Ammonium Bromide (CTAB) to improve the phase change capability of polyvinylidene fluoride (PVDF), increases the nucleation rate of the gamma-phase of polyvinylidene fluoride and accelerates the growth rate of the gamma-phase under the action of low-temperature nucleation and high-temperature crystallization, and can quickly prepare a high-temperature resistant PVDF dielectric film; has the characteristics of high polar phase content, short time and easy industrialization.
In order to achieve the purpose, the invention adopts the technical scheme that:
a preparation method of an oriented gamma-phase PVDF/CTAB composite film specifically comprises the following steps:
1) respectively placing PVDF and CTAB granules in a vacuum oven at 70-90 ℃, and drying for 12-24h to remove moisture;
2) uniformly mixing the PVDF and CTAB granules dried in the step 1) in a mass ratio of 100/0-100/2; and pressing the sample into a shaped sample at the temperature of 190-200 ℃ by using a hot press;
3) cooling the shaped sample prepared in the step 2) to room temperature in a room temperature environment to obtain a PVDF/CTAB shaped sample;
4) stretching the shaped sample in the step 3) in a high-low temperature tensile machine at the stretching temperature of 150 ℃ and 160 ℃ and at the stretching speed of 5-1000mm/min to obtain the PVDF/CTAB composite film.
The mass average molecular weight of the PVDF pellets in the step 1) is 71000.
The mass average molecular weight of the CTAB pellets in said step 1) was 364.45.
And (3) stretching at the temperature of 150 ℃ and 160 ℃ for 5-1000mm/min in the step 4) to prepare the PVDF/CTAB composite film, and characterizing by using an infrared spectrum means, wherein the result shows that the crystal form is a beta + gamma crystal form.
The shaped sample can be a cuboid, a cone, a cylinder or other regular or irregular shapes, and is preferably a dumbbell-shaped sample.
The invention has the beneficial effects that:
according to the invention, CTAB is adopted to improve the phase change capability of PVDF, oriented gamma-phase PVDF is obtained under the action of high-temperature stretching, the nucleation rate of the gamma-phase of polyvinylidene fluoride is increased under the action of low-temperature nucleation and high-temperature crystallization, and the growth rate of the gamma-phase is accelerated; oriented gamma-phase PVDF can be rapidly prepared, and the content of the gamma-phase can reach 89%. The invention adopts the high molecular crystal material to prepare the multifunctional composite film with the dielectric property to replace the traditional ceramic dielectric material, the preparation method has simple process and convenient operation, and the PVDF has excellent dielectric property and high temperature resistance, and is hopeful to be applied in the fields of pressure sensors, lithium ion batteries, automobile motors, high temperature resistance thermistor devices and the like.
Drawings
FIG. 1 is a Fourier infrared spectrum of example 1 of the present invention.
FIG. 2 is a Fourier infrared spectrum of example 3 of the present invention.
Detailed Description
The invention is described in further detail below with reference to the figures and specific examples.
Example 1:
a preparation method of an oriented gamma-phase PVDF/CTAB composite film specifically comprises the following steps:
1) putting PVDF and CTAB granules into a vacuum oven at 70 ℃, drying for 12h and removing water;
2) uniformly mixing the granules dried in the step 1) according to the mass ratio of 100/0.1, and pressing the granules into a dumbbell-shaped sample at 190 ℃;
3) rapidly cooling the dumbbell type sample in the step 2) at room temperature to obtain a PVDF/CTAB dumbbell type sample;
4) stretching the dumbbell type sample in the step 3) in a high-low temperature tensile machine at the stretching temperature of 150 ℃ at the stretching speed of 5mm/min to prepare the PVDF/CTAB composite film.
Example 2:
a preparation method of an oriented gamma-phase PVDF/CTAB composite film specifically comprises the following steps:
1) putting PVDF and CTAB granules into a vacuum oven at 75 ℃ respectively, and drying for 14h to remove moisture;
2) uniformly mixing the granules dried in the step 1) according to the proportion of 100/0.2, and pressing the granules into a dumbbell-shaped sample at the temperature of 192 ℃ by using a hot press;
3) rapidly cooling the dumbbell type sample in the step 2) at room temperature to obtain a PVDF/CTAB dumbbell type sample;
4) stretching the dumbbell type sample in the step 3) in a high-low temperature tensile machine at the stretching temperature of 152 ℃ at the stretching speed of 10mm/min to prepare the PVDF/CTAB composite film.
Example 3:
a preparation method of an oriented gamma-phase PVDF/CTAB composite film specifically comprises the following steps:
1) putting PVDF and CTAB granules into a vacuum oven at 80 ℃ respectively, and drying for 16h to remove moisture;
2) uniformly mixing the granules dried in the step 1) according to the proportion of 100/0.5, and pressing the granules into a dumbbell-shaped sample at the temperature of 194 ℃ by using a hot press;
3) rapidly cooling the dumbbell type sample in the step 2) at room temperature to obtain a PVDF/CTAB dumbbell type sample;
4) stretching the dumbbell type sample in the step 3) in a high-low temperature tensile machine at the stretching temperature of 154 ℃ and the stretching speed of 50mm/min to prepare the PVDF/CTAB composite film.
Example 4:
a preparation method of an oriented gamma-phase PVDF/CTAB composite film specifically comprises the following steps:
1) putting PVDF and CTAB granules into a vacuum oven at 85 ℃ respectively, and drying for 20h to remove moisture;
2) uniformly mixing the granules dried in the step 1) according to the proportion of 100/1, and pressing the granules into a dumbbell-shaped sample at the temperature of 196 ℃ by using a hot press;
3) rapidly cooling the dumbbell type sample in the step 2) at room temperature to obtain a PVDF/CTAB dumbbell type sample;
4) stretching the dumbbell type sample in the step 3) in a high-low temperature tensile machine at the stretching temperature of 156 ℃ and the stretching speed of 100mm/min to prepare the PVDF/CTAB composite film.
Example 5:
a preparation method of an oriented gamma-phase PVDF/CTAB composite film specifically comprises the following steps:
1) putting PVDF and CTAB granules into a vacuum oven at 90 ℃ respectively, and drying for 24h to remove moisture;
2) uniformly mixing the granules dried in the step 1) according to the proportion of 100/2, and pressing the granules into a dumbbell-shaped sample at the temperature of 200 ℃ by using a hot press;
3) rapidly cooling the dumbbell type sample in the step 2) at room temperature to obtain a PVDF/CTAB dumbbell type sample;
4) stretching the dumbbell type sample in the step 3) in a high-low temperature tensile machine at the stretching temperature of 160 ℃ and the stretching speed of 500mm/min to prepare the PVDF/CTAB composite film.
The PVDF/CTAB composite films prepared in examples 1 to 5 were characterized by using infrared spectroscopy, and it was found that PVDF in the blended film was in the form of a beta + gamma crystal.
Comparative example:
1) 2g of PVDF granules are placed in a vacuum oven at 70 ℃, and dried for 24 hours to remove moisture;
2) pressing the PVDF granules dried in the step 1) into a dumbbell type sample by a hot press at the temperature of 190 ℃ and 200 ℃;
3) rapidly cooling the dumbbell type sample in the step 2) at room temperature to obtain the PVDF dumbbell type sample.
4) Stretching the dumbbell type sample in the step 3) in a high-low temperature tensile machine at the stretching temperature of 160 ℃ and the stretching speed of 5mm/min to obtain the PVDF sample film.
And (3) the infrared spectrum characterization result of the cooled PVDF film sample shows that the PVDF only contains the alpha crystal form.
The mass average molecular weight of the PVDF pellets in the step 1) is 71000.
The mass average molecular weight of the CTAB pellets in said step 1) was 364.45.
Referring to fig. 1, pure PVDF is stretched at 160 ℃, the phase of the PVDF crystal is not changed, and after CTAB is added, the PVDF crystal is changed into a solid-solid phase, and is changed into a β + α phase, and after stretching, the PVDF crystal is changed into a β + γ phase, and is oriented into a γ phase.
Referring to fig. 2, it can be seen that the phase change of PVDF/CTAB with the same ratio is different under the stretching action of different rates, and the higher the stretching rate is, the stronger the phase change capability is.
According to the invention, CTAB is adopted to improve the phase change capability of PVDF, and oriented gamma-phase PVDF is obtained under the action of high-temperature stretching. The detection comparison shows that the stretched PVDF/CTAB composite film contains a large amount of oriented gamma-phase PVDF.

Claims (10)

1. A preparation method of an oriented gamma-phase PVDF/CTAB composite film is characterized by comprising the following steps: the method specifically comprises the following steps:
1) respectively placing PVDF and CTAB granules in a vacuum oven at 70-90 ℃, and drying for 12-24h to remove moisture;
2) uniformly mixing the PVDF and CTAB granules dried in the step 1) in a mass ratio of 100/0-100/2; and pressing the sample into a shaped sample at the temperature of 190-200 ℃ by using a hot press;
3) cooling the existing sample prepared in the step 2) to room temperature in a room temperature environment to obtain a PVDF/CTAB dumbbell sample;
4) stretching the shaped sample in the step 3) in a high-low temperature tensile machine at the stretching temperature of 150 ℃ and 160 ℃ and at the stretching speed of 5-1000mm/min to obtain the PVDF/CTAB composite film.
2. The method for preparing the oriented gamma-phase PVDF/CTAB composite film according to claim 1, which is characterized in that: the PVDF/CTAB composite film prepared in the step 4) is characterized by an infrared spectrum means, and the result shows that the crystal form is a beta + gamma crystal form.
3. The method for preparing the oriented gamma-phase PVDF/CTAB composite film according to claim 1, which is characterized in that: the mass average molecular weight of the PVDF pellets in the step 1) is 71000.
4. The method for preparing the oriented gamma-phase PVDF/CTAB composite film according to claim 1, which is characterized in that: the mass average molecular weight of the CTAB pellets in said step 1) was 364.45.
5. The method for preparing the oriented gamma-phase PVDF/CTAB composite film according to claim 1, which is characterized in that: the shaped sample can be a cuboid, a cone, a cylinder or other regular or irregular shapes, and is preferably a dumbbell-shaped sample.
6. The method for preparing the oriented gamma-phase PVDF/CTAB composite film according to claim 1, which is characterized in that: the method specifically comprises the following steps:
1) putting PVDF and CTAB granules into a vacuum oven at 70 ℃, drying for 12h and removing water;
2) uniformly mixing the granules dried in the step 1) according to the mass ratio of 100/0.1, and pressing the granules into a dumbbell-shaped sample at 190 ℃;
3) rapidly cooling the dumbbell type sample in the step 2) at room temperature to obtain a PVDF/CTAB dumbbell type sample;
4) stretching the dumbbell type sample in the step 3) in a high-low temperature tensile machine at the stretching temperature of 150 ℃ at the stretching speed of 5mm/min to prepare the PVDF/CTAB composite film.
7. The method for preparing the oriented gamma-phase PVDF/CTAB composite film according to claim 1, which is characterized in that: the method specifically comprises the following steps:
1) putting PVDF and CTAB granules into a vacuum oven at 75 ℃ respectively, and drying for 14h to remove moisture;
2) uniformly mixing the granules dried in the step 1) according to the proportion of 100/0.2, and pressing the granules into a dumbbell-shaped sample at the temperature of 192 ℃ by using a hot press;
3) rapidly cooling the dumbbell type sample in the step 2) at room temperature to obtain a PVDF/CTAB dumbbell type sample;
4) stretching the dumbbell type sample in the step 3) in a high-low temperature tensile machine at the stretching temperature of 152 ℃ at the stretching speed of 10mm/min to prepare the PVDF/CTAB composite film.
8. The method for preparing the oriented gamma-phase PVDF/CTAB composite film according to claim 1, which is characterized in that: the method specifically comprises the following steps:
1) putting PVDF and CTAB granules into a vacuum oven at 80 ℃ respectively, and drying for 16h to remove moisture;
2) uniformly mixing the granules dried in the step 1) according to the proportion of 100/0.5, and pressing the granules into a dumbbell-shaped sample at the temperature of 194 ℃ by using a hot press;
3) rapidly cooling the dumbbell type sample in the step 2) at room temperature to obtain a PVDF/CTAB dumbbell type sample;
4) stretching the dumbbell type sample in the step 3) in a high-low temperature tensile machine at the stretching temperature of 154 ℃ and the stretching speed of 50mm/min to prepare the PVDF/CTAB composite film.
9. The method for preparing the oriented gamma-phase PVDF/CTAB composite film according to claim 1, which is characterized in that: the method specifically comprises the following steps:
1) putting PVDF and CTAB granules into a vacuum oven at 85 ℃ respectively, and drying for 20h to remove moisture;
2) uniformly mixing the granules dried in the step 1) according to the proportion of 100/1, and pressing the granules into a dumbbell-shaped sample at the temperature of 196 ℃ by using a hot press;
3) rapidly cooling the dumbbell type sample in the step 2) at room temperature to obtain a PVDF/CTAB dumbbell type sample;
4) stretching the dumbbell type sample in the step 3) in a high-low temperature tensile machine at the stretching temperature of 156 ℃ and the stretching speed of 100mm/min to prepare the PVDF/CTAB composite film.
10. The method for preparing the oriented gamma-phase PVDF/CTAB composite film according to claim 1, which is characterized in that: the method specifically comprises the following steps:
1) putting PVDF and CTAB granules into a vacuum oven at 90 ℃ respectively, and drying for 24h to remove moisture;
2) uniformly mixing the granules dried in the step 1) according to the proportion of 100/2, and pressing the granules into a dumbbell-shaped sample at the temperature of 200 ℃ by using a hot press;
3) rapidly cooling the dumbbell type sample in the step 2) at room temperature to obtain a PVDF/CTAB dumbbell type sample;
4) stretching the dumbbell type sample in the step 3) in a high-low temperature tensile machine at the stretching temperature of 160 ℃ and the stretching speed of 500mm/min to prepare the PVDF/CTAB composite film.
CN202110620855.4A 2021-06-03 2021-06-03 Preparation method of oriented gamma-phase PVDF/CTAB composite film Pending CN113336986A (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114409944A (en) * 2022-02-24 2022-04-29 陕西科技大学 Method for rapidly inducing polyvinylidene fluoride film to generate alpha-gamma phase change
CN114953296A (en) * 2022-05-26 2022-08-30 业成科技(成都)有限公司 Manufacturing method of polycrystalline phase polyvinylidene fluoride film and wearable device
CN115028871A (en) * 2022-06-22 2022-09-09 陕西科技大学 Method for preparing oriented gamma-phase polyvinylidene fluoride film

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102875938A (en) * 2012-09-28 2013-01-16 四川大学 Polar crystal-form polyvinylidene fluoride and preparation method of composite thereof
CN106832690A (en) * 2017-01-18 2017-06-13 苏州固泰新材股份有限公司 A kind of preparation method of polyvinylidene difluoride film
CN108342036A (en) * 2018-03-26 2018-07-31 南昌航空大学 A kind of magnetism Mxenes polymer composite wave-suction materials and preparation method thereof

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102875938A (en) * 2012-09-28 2013-01-16 四川大学 Polar crystal-form polyvinylidene fluoride and preparation method of composite thereof
CN106832690A (en) * 2017-01-18 2017-06-13 苏州固泰新材股份有限公司 A kind of preparation method of polyvinylidene difluoride film
CN108342036A (en) * 2018-03-26 2018-07-31 南昌航空大学 A kind of magnetism Mxenes polymer composite wave-suction materials and preparation method thereof

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114409944A (en) * 2022-02-24 2022-04-29 陕西科技大学 Method for rapidly inducing polyvinylidene fluoride film to generate alpha-gamma phase change
CN114953296A (en) * 2022-05-26 2022-08-30 业成科技(成都)有限公司 Manufacturing method of polycrystalline phase polyvinylidene fluoride film and wearable device
CN114953296B (en) * 2022-05-26 2023-08-29 业成科技(成都)有限公司 Manufacturing method of polycrystalline polyvinylidene fluoride film and wearable device
CN115028871A (en) * 2022-06-22 2022-09-09 陕西科技大学 Method for preparing oriented gamma-phase polyvinylidene fluoride film

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