高聚合度聚氯乙烯材料的加工改性研究

研制了ＤＯＰ,ＭＢＳ,ＡＣＲ改性剂对合度聚氯乙烯加工性能和改性体系力学性能的影响,结果表明：ＤＯＰ对高聚合度聚氯乙烯材料的加工性有明显的改善,能满足挤出、注射成型的工艺要求,但随着ＤＯＰ的含量增加材料的力学性能下降很大;ＭＢＳ,ＡＣＲ改性高聚合度聚氯乙烯,不但使改性体系塑化为改善,冲击强度有明显提高,而且共混材料的拉伸强度下降不大。     

HPVC/SBR共混体系相容性的研究

采用动态硫化方法制备高聚合度聚氯乙烯（ＨＰＶＣ）／ＳＢＲ共混型热塑性弹性体,考察了单一组分相容剂「相容剂分别为ＮＢＲ２７０、ＮＢＲ Ｐ６５、ＣＰＥ和氢化苯乙烯－丁二烯、苯乙烯嵌段共聚物（ＳＥＢＳ）」、复合相容剂（ＳＥＢＳ／ＮＢＲ和ＣＰＥ／ＮＢＲ）及交联程度对ＨＰＶＣ／ＳＢＲ共混体系相容性的影响。结果表明,使用复合相容剂可明显改善ＨＰＶＣ／ＳＢＲ共混物的性能;动态硫化在改善共混物力学性能方面起主要作     

CPE,CV及其与ACR,MBS复合增韧RPVC的研究

考察了不同ＣＰＥ牌号及用ＣＰＥ－ＰＶＣ接枝共聚物（ＣＶ）部分或全部代替ＣＰＥ对改善Ｒ－ＰＶＣ冲击和拉伸性能的影响,在此基础上,研究了复合增韧体系（ＣＰＥ、ＣＶ分别与ＡＣＲ、ＭＢＳ并用或ＣＰＥ、ＣＶ同时和ＡＣＲ并用等）对提高Ｒ－ＰＶＣ力学性能的影响。结果表明,ＣＰＥ的分子量高、氯含量分布窄和氯含量高、残余结晶度高分别对提高Ｒ－ＰＶＣ的冲击和拉伸强度有利;ＣＶ与ＣＰＥ并用能提高Ｒ－ＰＶＣ的冲击强度,并且拉伸强度的损失较单独使用ＣＰＥ为小,并用时其组成比以１１为宜;ＣＰＥ、ＣＶ与ＡＣＲ或ＭＢＳ联合使用,在适宜组成比下能对Ｒ－ＰＶＣ产生协同增韧效应,改善体系的相容性,提高冲击性能并保留较高的其它力学强度,这是解决目前ＰＶＣ／ＣＰＥ共混材料性能缺陷的有效方法。     

聚氯乙烯／丁腈橡胶共混型热塑性弹性体流变性能的研究

采用毛管流变仪研究了聚氯乙烯（ＰＶＣ）／丁腈橡胶（ＮＢＲ）共混型热塑性弹性体的流变性能。试验结果表明，ＰＶＣ／ＮＢＲ热塑性弹性体熔体是一种典型的假塑性流体，并遵从幂律流体规律。橡胶含量和硫黄用量降低或增塑剂ＤＯＰ用量增加均可降低熔体的表观粘度。采用高速混炼和返炼的方法，可使熔体粘度减小，挤出物外观质量明显改善。     

核／壳型丙烯酸酯类R－PVC改性剂的研究

采用二步乳液聚合技术、合成了具有核／壳结构的硬质聚氯乙烯（Ｒ—ＰＶＣ）改性剂ＣＳ—ＡＣＲ—ＩＶ。借助于透射电镜和动态粘弹谱仪，考察了此改性剂的形态结构。利用Ｂｒａｂｅｎｄｅｒ塑化仪和毛细管流变仪研究了ＣＳ—ＡＣＲ—ＩＶ的用量及合成参数对Ｒ—ＰＶＣ加工性能的影响。试验结果表明，具有核／壳结构的ＣＳ—ＡＣＲ—ＩＶ能明显促进Ｒ—ＰＶＣ的塑化并降低熔体的表观粘度。     

CPE与ACR或MBS复合增韧R—PVC体系的流变性能研究

本文主要研究了ＣＰＥ／ＡＣＲ、ＣＰＥ／ＭＢＳ复合增韧ＲＰＶＣ体系的熔体剪切粘度（ηα）与增韧剂组成比（Ｒｃ）的关系。结果表明,两种三元共混物的ηαＲｃ关系明显不同;定Ｒｃ和γ下的ηα,ＣＰＥ／ＡＣＲ体系＜ＣＰＥ／ＭＢＳ体系;该ηα差别随Ｒｃ增加而增大,随γ增加而减小。其流变特性与增韧组份间相互作用和相分散形态有关。     

SAN对PVC／CPE加工行为的影响

采用Ｂｒａｂｅｎｄｅｒ塑化仪和双辊开炼机，研究了几种刚性有机填料ＳＡＮ（苯乙烯和丙烯腈的共聚物）对ＰＶＣ／ＣＰＥ（聚氯乙烯／氯化聚乙烯）共混体加工行为及力学性能的影响。实验表明：这几种ＳＡＮ均有缩短ＰＶＣ／ＣＰＥ塑化时间，改善熔融塑化行为的效能，但不同流动性的ＳＡＮ作用有所差异。还证实了不同加工方法的改性效果不尽相同。     

高聚合度PVC改性电缆料的研制

本文介绍采用不同改性剂对高聚合度ＰＶＣ进行改制造橡胶类改性热塑性电缆料，考察了塑化温度、改性剂、增塑化温度为１７５℃；丁腈胶Ｎ－４１是ＰＶＣ的良好改性剂；当ＣａＣＯ３用量为３０份，ＤＯＰ用量为６５－７５份（均以ＰＶＣ／Ｎ－４１为９０／１０，共计１００）时，可制得性能良好的改性电缆料。     

LARGE SCALE PURIFICATION OF PHOSPHOGLYCERATE KINASE（PGK） AND GLYCERALDEHYDE 3－PHOSPHATE DEHYDROGENASE（GAPDH） FROMYELLOW PEAS BY PEG／REPPAL PES AQUEOUS TWO PHASE SYSTEM AND ION EXCHANGE CHROMATOGRAPHY

ＬＡＲＧＥＳＣＡＬＥＰＵＲＩＦＩＣＡＴＩＯＮＯＦＰＨＯＳＰＨＯＧＬＹＣＥＲＡＴＥＫＩＮＡＳＥ（ＰＧＫ）ＡＮＤＧＬＹＣＥＲＡＬＤＥＨＹＤＥ３－ＰＨＯＳＰＨＡＴＥＤＥＨＹＤＲＯＧＥＮＡＳＥ（ＧＡＰＤＨ）ＦＲＯＭＹＥＬＬＯＷＰＥＡＳＢＹＰＥＧ／ＲＥＰＰＡＬ...     

ENHANCEMENT OF ENERGY TRANSFER FROM THE TERMINAL CHROMOPHORE OF POLYETHER TO EUROPIUM CATION（Ⅲ）VIA C

ＥＮＨＡＮＣＥＭＥＮＴＯＦＥＮＥＲＧＹＴＲＡＮＳＦＥＲＦＲＯＭＴＨＥＴＥＲＭＩＮＡＬＣＨＲＯＭＯＰＨＯＲＥＯＦＰＯＬＹＥＴＨＥＲＴＯＥＵＲＯＰＩＵＭＣＡＴＩＯＮ（Ⅲ）ＶＩＡＣＯＭＰＬＥＸＡＴＩＯＮＥＮＨＡＮＣＥＭＥＮＴＯＦＥＮＥＲＧＹＴＲＡＮＳＦＥＲ...     

刚性聚合物改性PVC/CPE/CaCO_3共混体的研究

本文研究刚性聚合物(PS、PMMA)对CaCO_2填充的PVC/CPE共混体力学性能和流变性能的影响。结果表明,刚性聚合物的填入提高了共混体的冲击强度,其中,对PVC/CPE/CaCO_3=100/15/10体系的增韧效果较好。PMMA使共混体的拉伸强度有所提高而PS使共混体拉伸强度下降。流变性的测定显示,Ca-CO_2使共混体的表观粘度和粘流活化能增加,牛顿的流动性增强,而在PVC/CPE/CaCO_3共混体中加入4.5份PS能明显降低共混体的表观粘度和粘流活化能,牛顿的流动性降低,但仍有良好的挤出物外观和较低的挤出膨胀率。     

硬相粒子（PS）与弹性体（CPE）增韧聚氯乙烯研究

将最新的硬相增韧技术与传统的弹性体增韧方法相结合，对聚氯乙烯树脂进行改性，制备了综合性能优异的ＰＶＣ／ＣＰＥ／ＰＳ三元合金材料，其具有高韧性、高强度的特征，并能改善ＣＰＥ增韧ＰＶＣ时，耐热性，加工流动性变差的缺点。本文探讨了其改性效果的主要因素及增韧机理。     

纳米CaCO3增韧PVC/CPE复合材料的性能研究

研究了纳米CaCO3增韧PVC／CPE复合材料的力学性能和流变性能。结果表明，纳米CaCO3对PVC／CPE复合材料有明显的增韧作用，出现单峰最大值分布；并与CPE产生协同增韧效应。PVC／CPE复合材料的拉伸强度随纳米CaCO3和CPE的用量的增加而稍有下降。随纳米CaCO3的用量增加，PVC熔体的塑化时间延迟了5倍，凝胶速率提高了2倍，平衡粘度增加，操作范围变窄，加工难度增加。     

Nanocomposites of poly(vinyl chloride) and nanometric calcium carbonate particles: Effects of chlorinated polyethylene on mechanical properties,morphology, and rheology

Nanocomposites of poly(vinyl chloride) (PVC) and nano‐calcium carbonate (CaCO₃) particles were prepared via melt blending, and chlorinated polyethylene (CPE) as an interfacial modifier was also introduced into the nanocomposites through preparing CPE/nano‐CaCO₃ master batch. The mechanical properties, morphology, and rheology were studied. A moderate toughening effect was observed for PVC/nano‐CaCO₃ binary nanocomposites. The elongation at break and Young's modulus also increased with increasing the nano‐CaCO₃ concentration. Transmission electron microscopy (TEM) study demonstrated that the nano‐CaCO₃ particles were dispersed in a PVC matrix uniformly, and a few nanoparticles agglomeration was found. The toughening effect of the nano‐CaCO₃ particles on PVC could be attributed to the cavitation of the matrix, which consumed tremendous fracture energy. The notched Izod impact strength achieved a significant improvement by incorporating CPE into the nanocomposites, and obtained the high value of 745 J/m. Morphology investigation indicated that the nano‐CaCO₃ particles in the PVC matrix was encapsulated with a CPE layer through preparing the CPE/nano‐CaCO₃ master batch. The evaluation of rheological properties revealed that the introduction of nano‐CaCO₃ particles into PVC resulted in a remarkable increase in the melt viscosity. However, the viscosity decreased with addition of CPE, especially at high shear rates; thus, the processability of the ternary nanocomposites was improved. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2714–2723, 2004     

Miscibility and rheological properties of poly(vinyl chloride)/styrene–acrylonitrile blends prepared by melt extrusion

Styrene–acrylonitrile (SAN) with acrylonitrile (AN) concentrations of 11.6–26 wt % and α‐methylstyrene acrylonitrile (αMSAN) with a wide range of AN concentrations are miscible with poly(vinyl chloride) (PVC) through solution blending. Here we examine the rheological properties and miscibility of PVC/SAN and PVC/αMSAN blends prepared by melt extrusion for commercial applications. We have investigated the rheological properties of the blends with a rheometer and a melt indexer. The PVC/SAN and PVC/αMSAN blends have a low melting torque, a long degradation time, and a high melt index, and this means that they have better processability than pure PVC. The miscibility of the blends has been characterized with differential scanning calorimetry, dynamic mechanical thermal analysis, and advanced rheometrics expansion system analysis. The miscibility of the blends has also been characterized with scanning electron microscopy. The SAN series with AN concentrations of 24–31 wt % is immiscible with PVC by melt extrusion, whereas αMSAN with 31 wt % AN is miscible with PVC, even when they are blended by melt extrusion, because of the strong interaction between PVC and αMSAN. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Studies on mechanical and rheological properties of poly(vinyl chloride) modified with elastomers and rigid organic particles

Chlorinated polypropylene (CPP) as rigid organic particles and chlorinated polyethylene (CPE) as elastomer were used to modify the properties of poly(vinyl chloride) (PVC) by melt blending. Both mechanical and rheological properties of the PVC blends were investigated. The submicroscopic morphology of the blends was observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results demonstrate that when the weight ratio of CPE to CPP is about 6 : 1, a sample with the best impact strength and without obvious decline in tensile strength can be obtained. The impact strength correlates well with SEM morphologies, and TEM micrographs in the necking of the tensile specimen indicate that a cold‐drawing deformation of rigid particles happens as reported by T. Kurauchi and T. Ohta (J Mater Sci 1984, 19, 1699). Therefore, a conclusion can be drawn that CPP particles acting similar to elastic particles can toughen PVC, and the cold‐drawing deformation is the primary reason for toughening the PVC blends. In addition, the addition of CPP can promote the processibility of PVC ternary blends. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2478–2483, 2003     

固相法氯化聚乙烯增韧聚氯乙烯的研究──氯化聚乙烯的氯含量、制备条件与增韧聚乙烯性能的关系

本文研究了固相氯化法制备的氯化聚乙烯（ＣＰＥ）和ＰＶＣ／ＣＰＥ共混物的机械特性。氏考察了ＣＰＥ氯含量、氯化条件如聚乙烯晶区与非晶区氯化程度比、氯化过程中热处理条件、氯化温度等对聚氯乙烯（ＰＶＣ）增韧效果的影响。共混前后的物理力学性能变化表明，不仅氯含量、而且氯化聚乙烯的制备条件对ＰＶＧ的增韧效果有着很大的影响，而分子量对性能影响不大。因相法ＣＰＥ与悬浮法ＣＰＥ对ＰＶＣ的增韧效果相当，ＣＰＥ用量为７—１５ｐｈｒ时，增韧效果尤为突出。形态结构的表征结果说明共混物是微观上的相分离，具有优良增韧效果的体系为ＣＰＥ是均匀连续同分布于ＰＶＣ粒子表面。     

高分子量聚氯乙烯增塑体系及其改性研究

研究了ＨＭＷＰＶＣ和通用ＰＶＣ的增塑性能,采用ＣＰＥ、Ｐ８３ 和７４１ 改性剂对ＨＭＷＰＶＣ增塑体系进行改性,结果表明,随ＰＶＣ分子量增加,体系的拉伸强度,冲击回弹性,硬度、熔体平衡转矩、熔体温度提高,而软化温度和磨耗降低,动态热稳定时间缩短;ＤＯＰ用量的增加,呈现通常的增塑性能;加有ＣＰＥ的体系磨耗增加明显,７４１ 对体系的硬度,软化温度和冲击回弹性影响较显著,对于熔体性能的影响,则ＣＰＥ更为明显。     

核壳结构PMMA纳米微球增韧R-PVC/CPE

研究了核壳结构聚甲基丙烯酸甲酯（PMMA）纳米微球对硬质聚氯乙烯/氯化聚乙烯（R-PVC/CPE）体系的增韧和增强作用及其对加工流变性的影响。研究发现，核壳结构PMMA纳米微球与R-PVC/CPE基体在适当配比下共混，在显著提高基体的冲击强度的同时，拉伸强度、伸长率和加工流变性也有改善。