PVC/耐热改性剂共混体系的力学及耐热性能研究

以具有核壳结构的纳米级交联粒子为耐热改性剂,系统研究了聚氯乙烯(PVC)树脂/粒子耐热改性剂/甲基丙烯酸甲酯-丁二烯-苯乙烯共聚物(MBS)树脂三元共混体系的力学性能、维卡耐热性能及流变行为,探讨了刚性粒子和橡胶粒子在PVC树脂增韧和耐热改性过程中的相互作用及关键影响因素。结果表明:具有核壳结构的纳米离子型耐热改性剂可以显著提高PVC树脂的维卡软化温度,加入MBS树脂可提高共混物冲击强度。研究发现,PVC中加入8份MBS和15份耐热改性剂,可制得耐热、抗冲兼备的PVC共混新材料。     

氯化聚氯乙烯/聚氯乙烯/抗冲击改性剂共混对埋地式高压电力电缆套管的维卡软化温度及力学性能的影响

研究了氯化聚氯乙烯(PVC-C)/聚氯乙烯(PVC)/抗冲击改性剂(CPE/ACR)共混体系对埋地式高压电力电缆PVC-C护套管的维卡软化温度和力学性能的影响。结果表明,在基础配方不变的情况下,PVC-C/PVC共混体系中,随着PVC-C含量的增加,管材的维卡软化温度提高,抗冲击性能下降;在PVC-C/PVC配比不变的情况下,冲击改性剂CPE(氯化聚乙烯)和抗冲ACR(丙烯酸酯类共聚物)的加入份数的提高,管材的抗冲击性能提高,维卡软化温度降低。     

ChMI/MMA/HFPT共聚物提高PVC耐热性能的研究

通过N-环已基马来酰亚胺/甲基丙烯酸/六氟丙烯三聚体(ChMI/MMA/HFPT)共聚在共聚物骨架上引入氟元素,生产出聚氯乙烯(PVC)树脂的耐热改性剂。试验证明:共聚物可提高PVC树脂混合物玻璃化温度tg。维卡软化温度tv及极限氧指数(LOI),从而降低PVC耐热制品的成本。三元共聚物ChMI/MMA/HFPT的最佳配比为35/62/3(wt)。耐热改性剂加量占PVC树脂混合物10%时,可大大提高PVC制品的耐热性能。     

N-环己基马来酰亚胺／甲基丙烯酸甲酯／苯乙烯乳液共聚物与PVC共混的研究

通过乳液共聚合得到N-环己基马来酰亚胺(ChMI)、甲基丙烯酸甲酯(MMA)、苯乙烯(St)的三元共聚物(ECMS)，用共聚物作耐热改性剂与PVC共混，用TBA和TGA研究了共聚物含量对共混物热性能、力学性能、流变性能及维卡软化点的影响。结果表明随三元共聚物含量的增加，共混物的玻璃化温度及维卡软化点逐渐上升；PVC第一阶段降解完毕。后平台区残留量逐渐上升；拉伸强度提高，冲击强度下降；熔体表观粘度增加，呈假塑性流体。     

聚氯乙烯用耐热改性剂研究进展

综述了聚氯乙烯(PVC)树脂用耐热改性剂的研究进展,指出目前PVC用耐热改性剂主要为N-取代马来酰亚胺的共聚物及其衍生物、α-甲基苯乙烯类耐热改性剂、马来酸酐类耐热改性剂、耐热工程塑料及其他耐热改性剂等,详述了各类耐热改性剂对PVC树脂耐热性和力学性能的改善效果。最后,对PVC用耐热改性剂的未来发展方向进行了展望。     

新型PVC-C管材加工方便

常州市卓成塑料有限公司目前已成功地开发出1种类似聚氯乙烯(PVc)加工工艺的氯化聚氯乙烯(PVC—C)管材。新开发的新型管材具有以下优点：①可以用类似PVC加工工艺的方法加工，其维卡软化点不低于110℃；②耐热温度比未增塑聚氯乙烯(PVC—U)高30～40℃，比ABS高l5～25℃；③耐老化及耐化学介质腐蚀性比ABS和PVC—U高出许多；④材料的韧性和抗冲击性能不比PVC—U差，     

ChMI/MMA/St/HfA提高PVC耐热性能研究

通过在N-环己基马来酰亚胺/甲基丙烯酸甲酯/苯乙烯(ChMI/MMA/St)三元共聚物聚合过程中加入微量的含氟单体丙烯酸六氟丁酯(HfA)进行共聚,在共聚物骨架上引入氟元素,生产出共聚物用于改性聚氯乙烯(PVC)树脂。试验证明,三元共聚物和四元共聚物均可提高PVC树脂混合物玻璃化温度(tg)和维卡软化温度(tVicat);耐热改性剂中HfA加入可提高PVC混合料的加工性能;四元共聚物加入量占PVC树脂混合物15%(质量分数,下同),相当于加入三元共聚物25%的效果,可大大降低PVC耐热制品的成本。     

ChMI/ MMA/AN悬浮共聚物与PVC共混的研究

通过悬浮共聚得到了N－环己基马来酰亚胺（ChMI）、甲基丙烯酸甲酯（MMA）、丙烯腈（AN）三元共聚物（PCMA），用作耐热改性剂与PVC共混。考察了共聚物用量对共混物热性能、力学性能、流变性能的影响，用扫描电镜（SEM）观察其断面。结果表明：随共聚物用量的增加，共混物的玻璃化温度和维卡软化点明显提高；PVC第一阶段降解速率减小，降解守毕后平台区残留量逐渐上升；拉伸强度明显提高，冲击强度在一定比例范围内几乎不变；熔体表观粘度增加，呈假塑性流体。     

PVC-C/PVC/MBS三元共混材料的研究

研究了氯化聚氯乙烯(PVC-C) /聚氯乙烯(PVC)与抗冲改性剂MBS[聚丁二烯(PB)与甲基丙烯酸甲酯(MMA)及苯乙烯(St)按枝共聚物]的二儿共混物的物理力学性能和流变性能。结果表明:共混物的维卡软化点随PVC-C用量的增加而上升,在PVC-C/PVC=50 /50(质量比)处有一拐点。共棍物的拉伸强度、弯曲模量随PVC-C用量的增加而提高; 而冲山强度和断裂伸长率都随PVC-C用量增加而下降。共棍物中随PVC-C用量增加,塑化能力增强,平衡转矩上升。不同的加工助剂可降低共棍物熔体黏度,改善加工性能。     

氯化聚氯乙烯双壁波纹管研制成功

由轻工业塑料加工应用研究所双壁波纹管技术研究中心与昆山鹰仕塑胶有限公司联合开发成功氯化聚氯乙烯 (ＰＶＣ -Ｃ)双壁波纹管生产技术。据悉 ,该产品生产技术为国内领先水平。该管材的维卡软化温度达到 93℃以上 ,耐热性能优良 ,比普通硬聚氯乙烯双壁波纹管的维卡软化温度高十几度 ,达到高电力、电缆护套管的使用要求 ,使双壁波纹管又多了一个应用领域 ,具有良好的市场前景。氯化聚氯乙烯双壁波纹管研制成功     

固相法氯化聚氯乙烯的研制

采用气 固相搅拌式氯化法对影响聚氯乙烯氯化反应的条件进行了分析,得出了适宜的反应条件。结果表明,温度为115℃、时间为2h、氯气流量为500～550mL·min-1是较佳的反应条件。对聚氯乙烯的氯化反应机理及动力学特征作了初步的研究。当反应温度超过100℃时,反应由内控制控制。     

PVB边角料用于硬质聚氯乙烯的改性研究

利用汽车夹层玻璃生产中所产生的大量边角料聚乙烯醇缩丁醛(PVB)来改性硬质聚氯乙烯(PVC-U),以提高PVC-U的冲击性能,测试了PVC-U/PVB共混物的冲击性能、拉伸性能及加工性能,并用场发射环境扫描电子显微镜(SEM)对其进行了断面形貌分析.结果表明,当100份PVC-U中加入5份PVB时,PVC-U/PVB体系的相容性较好,其冲击性能是纯PVC-U的2倍以上,而体系的拉伸性能变化不大,同时加工性能也得到了很好的改善.     

PVC/黏土纳米复合材料研究进展

文章简要概述了黏土的有机改性机理,聚氯乙烯/黏土纳米复合材料的特性及其制备方法、结构与表征方面的研究进展。对熔融插层共混法、溶液插层共混法、原位聚合法和插层聚合法进行了介绍和比较,对聚氯乙烯/黏土纳米复合材料的重点研究领域和发展趋势提出了具有前瞻性的预测。     

The influence of poly(vinyl alcohol) suspending agents on suspension poly(vinyl chloride) morphology

The requirements for PVC suspension resin have changed considerably in the last few years, so much so that few companies have products on their ranges that are more than 4 or 5 years old. The suspending agent has a crucial influence on the morphology of the resin, so the changes in resin characteristics have largely been achieved by changes in the suspending agent systems. After a brief review of the mechanism of PVC suspension polymerisation, the properties of polymers made using PVOH suspending agents are related to changes in the latter. The effect of variations in PVAc degree of hydrolysis and viscosity are related to changes in surface tension. Methods of achieving higher porosity by using low hydrolysis co-suspending agents are described. It is shown that higher bulk densities can be achieved by delayed addition of the PVOH. Levels of conjugated unsaturation and copolymer distributions are also shown to have important influences.     

Effect of mechanochemical degradation on gelation and mechanical properties of PVC

The effect of vibromilling or jet milling on gelation and mechanical properties of poly(vinyl chloride) (PVC) was studied through SEM, FTIR, DSC, and mechanical properties tests. The experimental results show that the size of the grain and apparent density of PVC are decreased. The grains become much more loosely aggregated and the crystallinity of PVC is decreased during milling. The extensional fracture of degraded PVC is obviously different from that of undegraded PVC, the tensile strength and degree of gelation of degraded PVC are increased as compared with undegraded PVC. The mechanical properties of PVC are improved quite a lot after blending it with a small amount of mechanochemically degraded PVC. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 2273–2281, 1997     

透明PVC厚片材的研制

针对透明聚氯乙烯(PVC)厚片材的使用要求,进行了配方设计、优化及工艺参数的选择,分别讨论了抗冲击改性剂、热稳定剂、加工助剂、润滑剂等对透明PVC厚片材热稳定性、力学性能和透明性能的影响。提出了配方优化的原则和生产工艺,经过试验给出优化的生产工艺参数,研制出厚度大于1．2mm的透明PVC医用片材,满足使用要求。     

国内外聚氯乙烯生产及市场概况（Ⅱ）

分析了亚洲及中国的PVC树脂的生产及市场概况,并提出了我国PVC树脂的发展方向。     

Iodination of plasticized poly(vinyl chloride) in aqueous media via phase transfer catalysis

Nucleophilic substitution of chlorine on plasticized poly(vinyl chloride) (PVC) was carried out using potassium iodide (KI) in the presence of a phase transfer catalyst (PTC) in aqueous media. Iodination was confirmed using energy dispersive X‐ray analysis (EDAX). The extent of iodination was studied with respect to time, temperature, concentration of the reactants, as well as different PTCs. Among the different PTCs examined, tetrabutylammonium bromide (TBAB) and tetrabutylammonium hydrogen sulfate (TBAH) were found to be highly efficient for the reaction. About 25% increase in weight was observed for PVC sheets iodinated under optimal reaction conditions. The thermal stability of the modified PVC was found to be impaired upon iodination. The iodinated PVC released iodide ions when kept in distilled water, as evidenced by UV spectroscopy. Sustained release of iodide ion in distilled water was followed up for about 30 days. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 493–499, 2002; DOI 10.1002/app.10176     

Effects of the reinforcement and toughening of acrylate resin/CaCO3 nanoparticles on rigid poly(vinyl chloride)

Novel composite particles based on nanoscale calcium carbonate (nano‐CaCO₃) as the core and polyacrylates as the shell were first synthesized by in situ encapsulating emulsion polymerization in the presence of the fresh slush pulp of calcium carbonate (CaCO₃) nanoparticles. Subsequently, these modified nanoparticles were compounded with rigid poly(vinyl chloride) (RPVC) to prepare RPVC/CaCO₃ nanocomposites. At the same time, the effects of the reinforcement and toughening of these modified nanoparticles on RPVC were investigated, and the synergistic effect of modified nanoparticles with chlorinated polyethylene (CPE) was also studied. The results showed that in the presence of nano‐CaCO₃ particles, the in situ emulsion polymerization of acrylates was carried out smoothly, and polyacrylates successfully encapsulated on the surface of nano‐CaCO₃ to prepare the modified nanoparticles, breaking down nano‐CaCO₃ particle agglomerates, improving their dispersion in the matrix, and also increasing the particle–matrix interfacial adhesion. Thus, the effects of the reinforcement and toughening of these modified nanoparticles on RPVC were very significant, and the cooperative effect of the nanoparticles with CPE occurred in the united modification system. Scanning electron microscopy analyses indicated that large‐fiber drawing and network morphologies coexisted in the system of joint modification of nanoparticles with CPE. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3940–3949, 2007