软质高聚合度聚氯乙烯的改性研究

以软质高聚合度聚氯乙烯为对象,探讨了增塑剂品种及用量,粉末丁腈及混温度对共混物力学及流为性能的影响,在共混力学改性的基础上进行共混加工改性。     

聚氯乙烯的共混改性研究

以石油树脂与顺丁烯二酸酐加成，然后与异辛醇酯化反应制备了改性石油树脂（ＭＰＲ），并应用ＭＰＲ与聚氯乙烯进行共混改性，结果表明，适量ＭＰＲ的引入明显改善了ＰＶＣ的加工性能，并在保持共混改性ＰＶＣ材料的弯曲强度、拉伸强度等性能基本不变的情况下，显著提高材料的抗冲性能，制得了ＰＶＣ／ＭＰＲ共混硬制品，拓宽了ＰＶＣ的使用范围。     

粉末丁腈橡胶改性软质聚氯乙烯的应用试验

就粉末丁腈橡胶改性软质聚氯乙烯进行应用试验配方设计、样条制备及性能测试。讨论了不同含量的丁腈橡胶（NBR）、增塑剂DOP、填充剂C aCO3对共混物性能的影响,并确定了最佳配方。     

共混改性聚氯乙烯的研究状况

文中详细论述了共混改性PVC的研究发展状况,探讨了PVC的增韧改性机理。     

国内聚氯乙烯共混增韧改性研究进展

介绍我国聚氯乙烯共混增韧改性的研究现状。分别对弹性体及非弹性体的增韧机理、影响增韧效果的因素,以及最近取得的成果作了概述。     

弹性体的改性技术：第4章 弹性体的共混改性

弹性体的共混改性,是指弹性体与其他聚合物或某些低分子物通过掺合、动态部分硫化和动态全硫化进行共混,以实现弹性体改性的目的。本章主要介绍弹性体与某些聚合物的机械共混。     

用粉末丁腈橡胶改性高聚合度聚氯乙烯的研究

考察了高聚合度聚氯乙烯热塑性弹性体（HPVC-TPE）的基本力学性能、加工流变性能。系统地研究了HPVC软质材料、硬质材料的共混力学改性和共混加工改性。由具有包藏结构的粉末丁腈改性的HPVC制得的软质HPVC-TPE材料和研制的硬质HPVC材料的力学性能、耐老化性能、流变性能均达到或接近进口材料水平。挤出产品外观平整、光滑,接近进口挡雨条样品的水平。     

软聚氯乙烯热可逆交联性的研究

利用Diels-Alder热可逆反应,合成了含有端环戊二烯基(CPD)的硫醇盐,作为具有热可逆性的交联剂,并将其应用于软聚氯乙烯中。研究了交联剂用量、时间及温度对交联程度的影响。采用DTA差热分析对此交联剂的热可逆特性进行了研究,并通过刚果红法和转矩流变仪测试了热可逆共价交联软聚氯乙烯的热稳定性以及加工流动性。     

给水管用PVC的改性研究

采用活性碳酸钙和甲基丙烯酸甲酯-丁二烯-苯乙烯三元接枝共聚物(MBS)对PVC进行改性,研究了二者对改性PVC抗冲击性能的影响.结果表明,活性碳酸钙和MBS的加入,改性PVC的抗冲击性能可提高17.3％,改性PVC管在低温下的抗冲击性能得到明显提高.     

Viscoelastic Behavior and Deformation Mechanism of Soft Poly(vinyl chloride)

Effect of plasticizer, filler (CaCO₃, carbons), and nitrile-butadiene rubber on the elastic network structure of plasticized PVC was studied by step-cycle and stress relaxation measurements. It is proposed that the network of plasticized PVC comprise the main network (the true Gaussian network) formed by the entanglement of molecular chains and the secondary network formed by the interaction of chains (van der Waals force). The critical true strain at turning point on curves of recovery strain (?_c), residual strain (?_S), and viscous stress (Δσ) versus the true strain (?_H), respectively only depends on the entanglement density of main network. While, the recovery strain, the residual strain and the viscous stress relate to the secondary network. Plasticizer, CaCO₃, and carbons don't influence the main network structure, but can change the secondary network structure of PVC material. Nitrile-butadiene rubber, however, can change both the main and the secondary network structure of PVC material.     

聚氯乙烯／聚丙烯酸共混体系增容剂的合成及性能研究

利用聚氯乙烯的化学反应制备了丙烯酸代聚氯乙烯,用此与丙烯酸共聚,合成了聚氯乙烯接枝聚丙烯酸接枝共聚物;利用红外光谱仪表征了它们的化学结构,用此接枝共聚物作为ＰＶＣ／ＰＡＡ供混体系的增容剂;利用ＤＳＣ等实验方法研究了ＰＶＣ／ＰＡＡ增容体系的热性能及力学性能。实验结果表明,所合成的接枝共聚物能够显著提高聚氯乙烯与聚丙烯酸的相容性,当接枝率为０．５７时,增容效果最佳。     

Photooxidative degradation of carboxylated poly(vinyl chloride)

Thin films of poly(vinyl chloride), PVC, and carboxylated poly(vinyl chloride), C-PVC, containing 1.8% of carboxyl groups were exposed to high energy ultraviolet radiation (λ = 254 nm) in laboratory conditions. The photochemical reactions in irradiated samples were studied by FTIR and UV–Vis spectroscopy, gel permeation chromatography and gravimetric estimation of insoluble gel. It was found that photodegradation and photocrosslinking in C-PVC is accelerated, whereas photodehydrochlorination is retarded comparing to these processes in PVC. Photooxidation investigated on the base of reaction leading to formation of hydroxyl groups is also more efficient in modified PVC. However, the total amount of carbonyl groups is much lower in UV-irradiated C-PVC than that in PVC. It indicates that competitive reactions (destruction of carboxyl groups and formation of new carbonyls) occur simultaneously in C-PVC chains. The influence of carbonyl groups on photochemical processes can be explained by an efficient Norrish I and II reactions as well as by energy transfer from absorbing species to weak chemical bonds.     

Application of Poly(butylenes 2-methylsuccinate) as Migration Resistant Plasticizer for Poly(vinyl chloride)

The bio-based and biodegradable polyester poly(butylenes 2-methylsuccinate) (PBM) was successfully used as a polymeric plasticizer to modify poly(vinyl chloride) (PVC) in this work. The tensile properties, plasticization efficiency estimated by the lowered glass transition temperature and the enhanced elongation at break of the PVC/PBM blends and the migration stability of the PBM were investigated. It was indicated that the migration-resistant property of PVC plasticized with PBM was greatly superior to that with dioctyl phthalate (DOP). Furthermore, the tensile properties were comparable to that of PVC/DOP, indicating that the environmentally friendly PBM can be used as an alternative plasticizer to remove the potential health risks from migrating phthalates during applications.     

热塑性聚氨酯与聚氯乙烯共混研究进展

综述了热塑性聚氨酯与聚氯乙烯共混改性研究进展，重点介绍了热塑性聚氨酯与聚氯乙烯共混物的相容性、共混方式、热塑性聚氨酯的类型和组分、助剂和第三组分聚合物等对共混物性能的影响及其应用。     

聚氯乙烯／丁腈橡胶共混体系的流变性能

本文研究了聚氯乙烯／丁腈橡胶共混体系的流变性能,并对用流变法测聚氯乙烯的相对凝胶废作了初步探讨。结果表明,该体系的流动符合假塑性流体的流动规律,表观粘度随剪切速度的增大而降低,熔体的粘流活化能具有剪切速率依赖性,弹性效应使溶体挤出胀大,胀大经胺剪切速率和温度的影响。     

国内聚氯乙烯抗冲击改性剂现状及发展趋势

介绍了几种重要的聚氯乙烯 (PVC)抗冲击改性剂 ,并对国内PVC抗冲击改性剂的发展前景进行了分析