宽熔融加工窗口聚乙烯醇共混物的制备及性能研究
发布时间：2019-03-26 17:37
【摘要】：聚乙烯醇(Poly(vinyl alcohol))是一种综合性能优异的水溶性高聚物。PVA的耐油、耐溶剂及气体阻隔性能尤其出众,在有机溶剂、食品药品等包装方面具有独特优势。PVA高分子链上含有大量的活性羟基易形成大量的分子内和分子间氢键,导致PVA的熔融温度与其热分解温度相当接近,熔融即分解,因而很难进行热塑加工。本文分别采用硅烷偶联剂KH602与KH560对PVA进行接枝改性,研究偶联剂对PVA熔点的影响;分别采用天然大分子丹宁酸和明胶与PVA共混,研究其对PVA热分解温度的影响。同时,制备不同碳链长度的烷基酚聚氧乙烯醚磷酸酯(NP-4P、NP-10P、NP-15P),分别研究其对PVA热稳定性和熔点的影响,最终制备了宽熔融加工窗口的聚乙烯醇共混物。分别采用硅烷偶联剂KH602和KH560对PVA进行接枝改性,制备了PVA-g-KH602和PVA-g-KH560改性材料。研究结果表明:两者的熔点分别由230℃降低至193℃和218℃,接触角分别从49°提高至92°和73°,在降低熔点方面,KH602的效果明显优于KH560。改性后,PVA的拉伸强度从87.5 MPa分别降低至59.6 MPa和64.5 MPa,断裂伸长率从156%分别提高到486%和338%。分别采用天然大分子丹宁酸(TA)和明胶(GEL)对PVA进行共混,制备了PVA/TA和PVA/GEL共混物。研究结果表明:与纯PVA相比,PVA/TA(7 wt%)和PVA/GEL(15wt%)共混物的热分解温度分别提高了103℃和87℃,熔点变化不大。随着TA和GEL含量的逐渐增加,PVA/TA和PVA/GEL共混材料仍具有优异的力学性能和透光率。分别采用不同碳链长度的磷酸酯类化合物(NP-4P、NP-10P、NP-15P)与PVA进行共混,结果表明,三种磷酸酯类化合物均能有效提高PVA的热分解温度,降低熔点。其中PVA/NP-10P(5 wt%)共混物效果最好,热分解温度升至311℃,熔点降低至213℃。分别采用微分法、Kissinger法以及Ozawa法探讨了PVA/NP-10P(5 wt%)与纯PVA的热降解动力学。结果表明,NP-10P可以有效地缓解PVA前期的热分解速率,提高其热稳定性。力学性能结果表明,随着NP-10P添加量的增多,PVA/NP-10P共混物的拉伸强度下降,断裂伸长率增加。当NP-10P的量为5 wt%时,PVA/NP-10P共混膜拉伸强度为72.2 MPa、断裂伸长率为473%,透光率为85%。进一步研究表明,在PVA-g-KH602中添加5 wt%的NP-10P制备宽熔融加工窗口PVA共混物,共混物熔点降低至185℃,热分解温度升为286℃,Td-Tm为101℃,易于热塑加工。力学和透光率结果表明:PVA-g-KH602(7%)/NP-10P共混物薄膜的拉伸强度为64.3 MPa,断裂伸长率为492%,透光率为74%,综合性能优异。
[Abstract]:Polyvinyl alcohol (Poly (vinyl alcohol) is a water-soluble polymer with excellent comprehensive properties. Its oil resistance, solvent resistance and gas barrier properties are especially outstanding in organic solvents. There are a lot of active hydroxyl groups in PVA macromolecular chain to form a large amount of intramolecular and intermolecular hydrogen bonds, which leads to the melting temperature of PVA is very close to its thermal decomposition temperature, that is to say, melting is decomposed. Therefore, it is difficult to carry out thermoplastic processing. In this paper, silane coupling agent KH602 and KH560 were used to graft PVA to study the effect of coupling agent on the melting point of PVA, and natural macromolecule tannic acid and gelatin were mixed with PVA to study the effect of coupling agent on the thermal decomposition temperature of PVA. At the same time, alkylphenol polyoxyethylene ether phosphate (NP-4P,NP-10P,NP-15P) with different carbon chain length was prepared, and its effects on thermal stability and melting point of PVA were studied respectively. Finally, polyvinyl alcohol blends with wide melting processing window were prepared. Silane coupling agents KH602 and KH560 were used to modify PVA to prepare PVA-g-KH602 and PVA-g-KH560 modified materials. The results show that the melting point of KH602 is decreased from 230 鈩，
本文编号：2447772
[Abstract]:Polyvinyl alcohol (Poly (vinyl alcohol) is a water-soluble polymer with excellent comprehensive properties. Its oil resistance, solvent resistance and gas barrier properties are especially outstanding in organic solvents. There are a lot of active hydroxyl groups in PVA macromolecular chain to form a large amount of intramolecular and intermolecular hydrogen bonds, which leads to the melting temperature of PVA is very close to its thermal decomposition temperature, that is to say, melting is decomposed. Therefore, it is difficult to carry out thermoplastic processing. In this paper, silane coupling agent KH602 and KH560 were used to graft PVA to study the effect of coupling agent on the melting point of PVA, and natural macromolecule tannic acid and gelatin were mixed with PVA to study the effect of coupling agent on the thermal decomposition temperature of PVA. At the same time, alkylphenol polyoxyethylene ether phosphate (NP-4P,NP-10P,NP-15P) with different carbon chain length was prepared, and its effects on thermal stability and melting point of PVA were studied respectively. Finally, polyvinyl alcohol blends with wide melting processing window were prepared. Silane coupling agents KH602 and KH560 were used to modify PVA to prepare PVA-g-KH602 and PVA-g-KH560 modified materials. The results show that the melting point of KH602 is decreased from 230 鈩，
本文编号：2447772
本文链接：https://www.wllwen.com/kejilunwen/huaxue/2447772.html
教材专著
