PVC管扩口定长系统的改进

介绍了一种新型的扩口定长系统,该系统利用光电开关、旋转编码器、计数器实现零件的定位,并利用计数器的原理将滚轮旋转信息转换为工作所要的计长仪信号,记录工程所需的长度.结果表明:该系统可以把误差由原来的几十毫米降低到±1毫米,有效地提高了成品的加工精度.     

合金化—聚氯乙烯分离膜材料改性及膜结构设计的新思路(Ⅰ)

本文介绍了PVC分离膜材料合金化对膜的亲水性、成膜性、膜结构、膜的分离渗透性能的影响.     

乙酰丙酮锌的制备、表征及其在PVC中的应用

以有机溶剂为分散剂,以乙酰丙酮和氢氧化锌为原料,合成了乙酰丙酮锌.将所制备的乙酰丙酮锌与其他热稳定剂原料复配,采用烘箱热老化法及流变实验,考察了乙酰丙酮锌对PVC的热稳定作用,结果表明：加入适量的乙酰丙酮锌,能显著提高PVC的初期着色性和长期热稳定性.     

Using Probabilistic Modeling to Evaluate Human Exposure to Organotin in Drinking Water Transported by Polyvinyl Chloride Pipe

The leaching of organotin (OT) heat stabilizers from polyvinyl chloride (PVC) pipes used in residential drinking water systems may affect the quality of drinking water. These OTs, principally mono- and di-substituted species of butyltins and methyltins, are a potential health concern because they belong to a broad class of compounds that may be immune, nervous, and reproductive system toxicants. In this article, we develop probability distributions of U.S. population exposures to mixtures of OTs encountered in drinking water transported by PVC pipes. We employed a family of mathematical models to estimate OT leaching rates from PVC pipe as a function of both surface area and time. We then integrated the distribution of estimated leaching rates into an exposure model that estimated the probability distribution of OT concentrations in tap waters and the resulting potential human OT exposures via tap water consumption. Our study results suggest that human OT exposures through tap water consumption are likely to be considerably lower than the World Health Organization (WHO) "safe" long-term concentration in drinking water (150 μg/L) for dibutyltin (DBT)—the most toxic of the OT considered in this article. The 90th percentile average daily dose (ADD) estimate of 0.034 ± 2.92 × 10⁻⁴μg/kg day is approximately 120 times lower than the WHO-based ADD for DBT (4.2 μg/kg day).     

Designing and analyzing a mixture experiment to optimize the mixing proportions of polyvinyl chloride composites

Polyvinyl chloride (PVC) products are typically complex composites, whose quality characteristics vary widely depending on the types and proportions of their components, as well as other processing factors. It is often required to optimize PVC production for specific applications at the highest cost efficiency. This study describes the design and analysis of a statistical experiment to investigate the effects of different parameters over the mechanical properties of PVC intended for use in electrical wire insulation. Four commonly used mixture components, namely, virgin PVC, recycled PVC, calcium carbonate, and a plasticizer, and two process variables, type of plasticizer and filler particle size, were examined. Statistical tools were utilized to analyze and optimize the mixture while simultaneously finding the proper process parameters. The mix was optimized to achieve required strength and ductility, as per ASTM D6096 while minimizing cost. The paper demonstrates how statistical models can help tailor complex polymeric composites in the presence of variations created by process variables.     

玻璃纤维增强聚氯乙烯复合材料的研究

阐述了玻璃纤维增强聚氯乙烯复合材料的制备方法及工艺现状，对该类材料的结构与性能的关系，特别是其界面层性质与材料性能的关系进行了叙述和分析，指出了该类复合材料的研究趋势     

PVC装潢材料的热分解特性分析

主要研究PVC装潢材料的热分解特性及机理.通过热失重实验对PVC装潢材料的热分解过程进行了分析,发现PVC的热分解明显分为3个阶段,由此建立了PVC的热解动力学模型,通过一种比较新颖的数学处理办法,确定此三个阶段皆为一级反应,并大体上推测了各阶段的主体反应.     

水悬浮法制备GF/PVC复合材料的加工性能的研究

考察了用不同悬浮液体系制备的复合材料的力学性能与模压温度、时间和压力的关系 ,并用扫描电子显微镜对复合材料中纤维 基体间的孔隙进行观察 ,结果发现 :在水悬浮法制备的GF PVC复合材料中 ,悬浮液中的高分子粘结剂对材料的加工性能有一定的影响 ,悬浮液中的Ⅰ ,Ⅱ及Ⅳ号高分子粘结剂能在一定的程度上改善PVC树脂的流动性 ,特别是Ⅳ号高分子粘结剂对体系的加工性能改善效果最好     

PP/PVC共混体系的研究进展

综述了国内外有关聚丙烯/聚氯乙烯共混体系的形态结构、热性能、动态力学性能、流变性能和物理力学性能的研究进展。分别介绍了非反应性、引入特殊作用基团和超支化聚合物增容剂改性聚丙烯/聚氯乙烯共混体系对其性能的影响。在聚丙烯/聚氯乙烯共混体系中加入增容剂使聚丙烯/聚氯乙烯共混体系的力学性能得到提高,两相之间的相分离程度减小,相容性改善。尤其是超支化聚合物增容剂和其它增容剂同时改性聚丙烯/聚氯乙烯共混体系,能够更加有效的提高其性能。