Method for promoting alpha-to-gamma crystal transformation of vinylidene fluoride

A polyvinylidene fluoride and crystal form transformation technology, applied in the field of polyvinylidene fluoride plastic modification, can solve the problems of high technical difficulty, low melting point of gamma crystal and high cost consumption

Inactive Publication Date: 2017-12-12
TIANJIN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The crystallization rate of γ-phase PVDF at high temperature can be promoted by adding nucleating agents such as KBr, but the resulting γ-crystal has a lower melting point
Other methods, such as anodic oxide alumi

Method used

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  • Method for promoting alpha-to-gamma crystal transformation of vinylidene fluoride
  • Method for promoting alpha-to-gamma crystal transformation of vinylidene fluoride
  • Method for promoting alpha-to-gamma crystal transformation of vinylidene fluoride

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] Add 100g PVDF (Solvay S.A., Brussels, Belgium.) to the banburying chamber of XSS-30 torque rheometer at 230°C, melt and banbury at 230°C for 10min, then add 0.05g graphene (Changzhou Sixth Element Material Technology Co., Ltd., SE1231), continue to melt and knead at 230 ° C for 15 minutes to fully mix graphene and PVDF, take out the tablet after banburying, and obtain a PVDF / graphene composite material. Carry out the same banburying process on PVDF pure material for comparison.

[0019] Add the banburyed PVDF / graphene composite material between the two heating plates of the flat vulcanizer, melt at 230°C for 10 minutes, then gradually pressurize to 30MPa, hold the pressure for 5 minutes, transfer to the cooling plate for holding pressure and shaping, and press to obtain 1mm thick sheet and cut it into a 18mm diameter disc.

[0020] Put the wafer into the shear cell of the CSS450 shear heat station, and heat up to 230°C at a heating rate of 30°C / min to melt the sample. ...

Embodiment 2

[0022] 100g PVDF (Solvay S.A., Brussels, Belgium.) was loaded into the mixing chamber of XSS-30 torque rheometer at 230°C, and melted and mixed at 230°C for 10min. Then add 0.5g graphene (Changzhou Sixth Element Materials Technology Co., Ltd., SE1231) and melt and knead at 230°C for 15 minutes to fully mix graphene and PVDF. After banburying, take out the tablet to prepare a PVDF / graphene composite Material. Carry out the same banburying process on PVDF pure material for comparison.

[0023] Load the good polyvinylidene fluoride / graphene composite material between the two heating plates of the flat vulcanizer, first melt it at 230°C for 10 minutes, then gradually increase the pressure to 30MPa, hold the pressure for 5 minutes, and then transfer it to the cooling plate for preservation. Press and shape, press into 1mm thick sheet, and it is cut into the disc of diameter 18mm.

[0024] Put the wafer into the shear cell of the CSS450 shear heat station, and heat up to 230°C at ...

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Abstract

The invention discloses a method for promoting alpha-to-gamma crystal transformation of vinylidene fluoride. The method for promoting alpha-to-gamma crystal transformation of the vinylidene fluoride comprises adding graphene into the vinylidene fluoride for melt-mixing to fully mixing the graphene and the vinylidene fluoride; extracting tablets, and performing melt isothermal crystallization; performing DSC (differential scanning calorimetry) testing on fully-crystallized samples, analyzing change of the crystal structure of the samples. The method for promoting alpha-to-gamma crystal transformation of the vinylidene fluoride discovers that adding in the graphene can improve the alpha-to-gamma crystal transformation rate of the vinylidene fluoride, and the higher the added content of the graphene is, the more significant the improvement is.

Description

technical field [0001] The invention belongs to the technical field of polyvinylidene fluoride plastic modification, and in particular relates to a method for promoting the polyvinylidene fluoride alpha→gamma crystal transformation process. Background technique [0002] Polyvinylidene fluoride (PVDF) is widely used in petrochemical, fluorocarbon coatings, and electronic components due to its good mechanical properties, thermal and chemical stability, high thermoelectric and piezoelectric coefficients, and easy processing and molding. , film products and other fields. [0003] Polyvinylidene fluoride is a common polymorphic polymer. So far, it has been reported that there are five crystal forms of α, β, γ, δ, and ε crystals, among which α, β, and γ crystals are common crystal forms. The alpha crystal obtained by cooling crystallization from the melt is the most stable and common crystal form of all crystal forms. In the α unit cell, the two molecular chains are arranged ant...

Claims

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Application Information

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IPC IPC(8): C08L27/16C08K3/04
CPCC08K3/04C08L2205/24C08L27/16
Inventor 蒋世春王本平李景庆王秀奎
Owner TIANJIN UNIV
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