【作者】 李林；

【导师】 范萍；

【作者基本信息】 浙江工业大学 ， 材料工程（专业学位）， 2020， 硕士

【摘要】 随着商品经济的不断发展,包装行业和广告装饰业也随之蓬勃发展,对包装或广告装饰用膜的需求也越加增大。聚乙烯醇（PVA）是一种100%生物降解绿色材料,并且PVA可采用非石油生产的路线大规模生产,受到了广泛关注。由于PVA结构规整,分子内存在很强的氢键,结晶度高使其熔融温度高于分解温度,导致熔融加工难度大。因此要解决PVA的热塑性加工问题,必须通过降低其熔点或提高其热分解温度的方法来创造出PVA的熔融加工窗口。本文采用少量离子液体作为PVA的热稳定剂,推高PVA热分解温度,从而获得PVA的熔融加工窗口。本文研究内容如下:（1）采用1-乙烯基-3-乙基咪唑四氟硼酸盐（BF₄IL）作为PVA的热稳定剂,制备PVA/BF₄IL共混物。结果表明:添加3wt%BF₄IL时,PVA/BF₄IL的熔点降低,热分解温度升高。与纯PVA相比,BF₄IL的加入,拓宽了PVA的热塑性加工窗口。此外,添加的3wt%BF₄IL,为PVA提供约100°C的热塑性加工窗口。同时,当加入3%BF₄IL时,透光率仍然保持在90%以上,几乎不会削弱PVA本身优秀的光学性能。（2）采用甲基丙烯酰氧乙基三甲基氯化铵（DMC）作为PVA的热稳定剂,制备PVA/DMC共混物。结果表明:与纯的PVA相比,PVA/DMC的最快分解温度从287.3°C升高至380.4°C。少量DMC的加入不影响PVA的结晶性能,PVA/DMC的熔融温度仍保持在纯PVA的221°C。这意味着少量DMC的加入可为PVA提供出一个约90°C的加工窗口。由于DMC对PVA的结晶性能没有影响,DMC也几乎不会削弱PVA本身优秀的力学性能、光学性能及耐水性能。更多还原

【Abstract】 With the continuous development of the commodity economy,the packaging industry and the advertising decoration industry have also prospered,and the demand for packaging or advertising decorative films has increased.Polyvinyl alcohol（PVA）is a kind of 100%biodegradable green material,which can be prepared on a large scale by non petroleum production route and has been widely concerned.Due to the regular structure,strong hydrogen bond and high crystallinity of PVA,the melting temperature of PVA is higher than the decomposition temperature,which makes the melting process more difficult.Therefore,in order to solve the thermoplastic processing problem of PVA,it is necessary to create a melt processing window of PVA by reducing its melting point or increasing its thermal decomposition temperature.In this paper,a small amount of ionic liquid is used as a heat stabilizer for PVA,in order to push up the thermal decomposition temperature of PVA,thereby obtaining a melt processing window of PVA,the research content of this paper is as follows:（1）PVA/BF₄IL blends are prepared by using 1-vinyl-3-ethylimidazolium tetrafluoroborate（BF₄IL）as heat stabilizer of PVA.The results show that when 3wt%BF₄IL is added,the melting point of PVA/BF₄IL decreases and the thermal decomposition temperature increases.Compared with pure PVA,the addition of BF₄IL widens the thermoplastic processing window of PVA.Moreover,the addition of 3wt%BF₄IL provides a thermoplastic processing window of about 100°C for PVA.At the same time,when 3%BF₄IL is added,the light transmittance is still maintained above 90%,which hardly impairs the excellent optical properties of the PVA itself.（2）PVA/DMC blend was prepared using methacryloyloxyethyltrimethyl ammonium chloride（DMC）as the heat stabilizer for PVA.The results show that the fastest decomposition temperature of PVA/DMC is increased from 287.3°C to380.4°C compared with pure PVA.The addition of a small amount of DMC did not affect the crystallization properties of PVA,and the melting temperature of PVA/DMC remained at 221°C of pure PVA.This means that the addition of a small amount of DMC provides a processing window of about 90°C for the PVA.Since DMC has no effect on the crystallization properties of PVA,DMC hardly impairs the excellent mechanical properties,optical properties and water resistance of PVA itself.更多还原