PVC共混增韧改性研究进展

阐述了近年来国内外聚氯乙烯(PVC)共混增韧改性的研究进展;介绍了PVC化学改性和物理改性;探讨了PVC弹性体共混增韧改性和刚性粒子共混增韧改性,尤其是纳米粒子共混增韧改性,指出了PVC共混增韧改性的研究前景及发展方向。     

聚氯乙烯共混增韧改性研究进展

概述了聚氯乙烯(PVC)树脂共混增韧改性体系的研究现状,包括PVC/弹性体和PVC/刚性粒子共混体系,并对PVC共混增韧改性体系的发展前景进行了展望。     

PS SAN 和AAS对PVC／ABS体系增韧改性的研究

采用非弹性体增韧的概念,探讨了三种有机刚性粒子(PS、SAN和AAS)对PVC/ABS二元体系的增韧改性作用,分析了有机刚性粒子增韧作用的影响因素和实现途径。结果表明,有机刚性粒子对PVC/ABS二元共混体系确有一定增韧作用,不同的刚性粒子对不同韧性的二元基体,增韧改性效果各不相同。     

PVC的共混改性研究进展

阐述了近年来对PVC的共混改性研究工作,总结了不同物质,如弹性体、塑料、无机刚性粒子增韧PVC的机理。并讨论了部分PVC树脂共混体系的相容性及改性效果。     

PVC的共温改性研究进展

阐述了近年来对PVC的共混改性研究工作，总结了不同物质，如弹性体、塑料、无机刚性粒子增韧PVC的机理。并讨论了部分PVC树脂共混体系的相容性及改性效果。     

聚氯乙烯增韧改性的研究进展

在大量文献的基础上简述了国内外聚氯乙烯(PVC)增韧改性的研究状况,从弹性体、刚性粒子、纤维状填料等共混增韧改性,到纳米技术的出现,对PVC的增韧改性赋予了PVC材料良好的性能,扩大了PVC的应用领域。但目前纳米粒子与PVC之间在纳米尺度上的相容性较差,因此加强理论研究上的深度,使这一新材料真正发挥其潜能,是今后重要的任务。     

刚性有机粒子对硬聚氯乙烯韧性体的增韧改性研究

研究了刚性有机粒子(如SAN,PS,PMMA树脂)对硬聚氯乙烯韧性体(指PVC/ABS,PVC/MBS,PVC/CPE等二元共混物)的改性效果。发现添加小份量有机粒子,能提高基体的冲击韧性,并保持基体拉伸强度不受损害或同时得到改善。不同粒子对各种硬PVC韧性体的改性效果不同,不同共混工艺的影响差别很大。初步得知,实现刚性有机粒子增韧改性的必要条件有:粒子与被增韧基体间的良好相容性;粒子与基体间的恰当的脆—韧比及要求基体本身有足够的强度和韧性。刚性有机粒子使共混物流变行为变佳,挤出物外观改善,挤出膨胀率下降,体系耐热性,热尺寸稳定性及耐酸碱性均有改善,显示出与传统的弹性体增韧不同的规律及特色。     

聚乳酸增韧改性研究进展

主要介绍了聚乳酸的化学增韧改性(共聚改性)和物理增韧改性(增塑、共混与无机刚性粒子复合),综述了近年来国内外聚乳酸增韧改性的研究现状及进展,并对今后聚乳酸增韧改性提出了建议。     

超细CaCO_3对PVC/ABS二元体系增韧改性的探讨

本实验采用了非弹性体增韧的概念,利用无机刚性粒子超细CaCO_3对PVC/ABS体系进行增韧改性。结果表明,CaCO_3用量为15份时,共混物的韧性有较大幅度的提高。本实验还考察了不同共混温度对体系增韧效果的影响。此外,运用J积分法对PVC/ABS/CaCO_3体系韧性进行了表征。     

增韧改性聚氯乙烯的研究进展

综述了近年来国内外对聚氯乙烯(PVC)增韧改性的方法,重点介绍了弹性体共混、纳米粒子填充、纤维增强、弹性体/纳米粒子复合材料增韧改性以及绿色填料在PVC增韧改性中的研究进展,指出了改性PVC复合材料具有广阔的应用前景。但开发价格低廉的纳米材料,简化生产工艺,降低产品成本,纳米复合材料增韧PVC的机理、多相协同增韧PVC的机理、不同填料的混杂效应及其协同机理、不同品种木粉改性PVC等尚需进一步研究。     

建筑塑料的增韧改性研究进展

综述了聚氯乙烯、聚丙烯、聚苯乙烯等常用建筑塑料的增韧改性研究进展，讨论了橡胶和热塑性弹性体共混增韧、刚性无机粒子增韧以及共聚、交联等化学增韧的方法和特点。     

聚偏二氯乙烯树脂增韧改性研究

介绍了聚偏二氯乙烯(PVDC)树脂的增韧改性方法,包括化学改性和物理改性方法。化学改性主要是通过提高氯乙烯(vC)单体含量、引人缩水甘油基丙烯酸甲酯(GMA)或丙烯腈(AN)单体来改善PVDC的韧性。物理改性方法主要有弹性体增韧改性和纳米碳酸钙刚性粒子增韧,文中主要介绍了PVDC和乙烯一酷酸乙烯共聚物(EVA)、甲基丙烯酸甲酷一丁二烯一苯乙烯共聚物(MBS)弹性体、丙烯酸酷共聚弹性体(ACR)的共混增韧体系。最后,指出了PVDC增韧改性的研究前景和发展方向。     

Vapor phase polymerization of vinyl chloride

A study of the polymerization of vinyl chloride was made at conditions under which the monomer exists in the gas phase. In the presence of a bed of poly(vinyl chloride) particles, free-flowing product was obtained. By using free-radical initiators, such as dialkylperoxy dicarbonates or acetylcyclohexane sulfonyl peroxide, high initiator productivities were obtained in reaction periods of 1.5 to 3 hr. Although some modifiers, such as ethyl bromomalonate and bromoform, were demonstrated to lower molecular weight, satisfactory molecular weight modification was accomplished by adjusting polymerization temperature. Several peroxy compounds of different reactivity were studied. Hydrocarbon additives improve the polymerization rate. It is believed that the hydrocarbon and initiator are absorbed on the PVC particle surface and allow the monomer concentration to be increased at the polymerization locus. PVC particles of small size may be prepared in a liquid bulk polymerization for use as seed polymer for the vapor phase process. This provides a seed of high porosity which enables one to prepare a vapor phase product with suitable plasticizer absorption. The physical properties of products prepared by the vapor phase process were evaluated in a rigid formulation.     

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。     

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     

聚氯乙烯增韧改性的研究现状

综述了目前国内外聚氯乙烯(PVC)增韧改性的研究状况和技术进展。分别对弹性体及刚性体的增韧机理、增韧剂种类和影响增韧效果的因素,以及最近取得的研究成果作了概述,指出了PVC增韧研究的发展趋势。     

PS增韧改性研究进展

介绍了目前国内外PS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PS增韧研究的发展方向和最近取得的成果进行了概述。     

Melt elasticity behavior and extrudate characteristics of rigid poly(vinyl chloride)/epoxidized natural rubber miscible blends

A study on the melt elasticity behavior and extrudate characteristics of melts of rigid poly(vinyl chloride), PVC, and rigid poly(vinyl chloride)/epoxidized natural rubber (ENR) miscible blends were conducted. Extrusion studies were carried out in a capillary rheometer and examinations of the surface characteristics of the extrudate were made by taking photomicrographs in a scanning electron microscope. The anomalous behavior in the die swell ratio of rigid PVC arising from the particle agglomerates continued in its blends up to 50 wt% composition of ENR. Temperature independence for high ENR blends was noted for the principal normal stress difference and elastic shear modulus, when shear stress was held constant. Recoverable shear strain and die swell ratio behaved identically in terms of blend composition and processing temperature. Factors which control the extrudate distortion and melt fracture of the melts of rigid PVC/ENR systems were fusion of particle agglomerates and strength of melts. Diamond cavitations were typical of the extrudate surface of PVC melts as those of the fracture surface of the tensile failure of PVC. Conditions to obtain a smooth extrudate surface of rigid PVC melts in blends with ENR have been found to be the low ENR content, low shear rate, or stress and high processing temperature.     

聚甲醛增韧改性的研究进展及应用

简述了聚甲醛（POM）的增韧改性方法,包括弹性体增韧改性、无机刚性粒子增韧改性、合金化增韧改性和复合增韧改性,综述了近些年来对POM进行增韧改性的研究进展,介绍了POM及其改性产品在各领域的应用,并对POM增韧改性的前景作出展望。     

The in situ polymerization of vinyl chloride in poly(butyl acrylate)

The in situ polymerization of vinyl chloride with poly(butyl acrylate) has been studied. Vinyl chloride was polymerized using a peroxydicarbonate initiator in sealed ampoules in the presence of various weights of poly(butyl acrylate). The products were examined by dynamic mechanical analysis and electron microscopy. It was found that if about 50% or less vinyl chloride was present in the mixture homogeneous blends were formed. If more than 50% vinyl chloride was present the polymerization passed through a two phase region in the three component phase diagram and inhomogeneous blends were formed. If homogeneous blends prepared as above were reswollen with vinyl chloride and the latter polymerized, then homogeneous blends containing more poly(vinyl chloride) could be prepared, avoiding the two phase region. The interaction parameters between vinyl chloride and both poly(vinyl chloride) and poly(butyl acrylate) were estimated using inverse gas chromatography. Using these and an estimate of the polymer/polymer interaction parameter the three component phase diagram could be qualitatively explained.