PVC树脂平均聚合度分析方法的探讨

在探讨了高聚合度聚氯乙烯树脂的平均聚合度(P)(黏数)的分析方法中,其溶液浓度对结果的准确度和精密度的影响。结果表明:当测定P<2000的PVC树脂的黏度和P时需使用质量浓度为0.0050g/mL的溶液进行分析;而测定P≥2000时的PVC树脂的黏度和P时则需使用质量浓度为0.0020g/mL的溶液进行分析。     

超低聚合度PVC树脂生产技术的研究

概述了国内超低聚合度PVC树脂生产工艺的研究进展以及应用情况,介绍了超低聚合度PVC树脂的研发过程,重点讨论了扩链剂巯基乙醇用量与平均聚合度和凝胶化温度之间的关系,并测试了超低聚合度PVC树脂的熔体流变性能和作为SG8型PVC树脂聚合物型增塑剂使用时的增塑效果。     

PVC树脂专用品生产技术的开发与应用

介绍了超低聚合度PVC树脂、高表观密度PVC树脂、消光PVC树脂、超高聚合度PVC树脂及高抗冲PVC树脂等几种专用PVC树脂的国内外生产、工艺、产品型号及应用情况。     

PVC专用树脂的现状与研究进展

与普通PVC树脂相比,消光PVC树脂具有更好的耐溶剂性和耐热性,其制品在外力作用下有较小的永久形变,加工尺寸稳定性好;高抗冲PVC树脂提高了制品的冲击强度和加工性能;耐热PVC树脂具有更好的耐热、耐溶剂、力学性能和加工尺寸稳定性;超高聚合度PVC具有较长的使用寿命,良好的抗撕裂性能;超低聚合度PVC树脂吸油能力强、熔融黏度低、塑化时间短,可显著改进硬制品的抗冲击性能。PVC树脂的研究和开发应朝着精细化、功能化、系列化的方向发展。     

悬浮法PVC树脂塑化的影响因素

简要分析了PVC树脂聚合度、树脂颗粒特性、加工设备、加工配方及助剂对悬浮法PVC树脂塑化的影响。     

卤素水分仪在PVC树脂生产中的应用

采用卤素水分仪法测定PVC树脂中所含的少量水分,并与常用的烘箱法进行了对比.指出采用烘箱法耗时长、测定结果波动较大,而采用卤素水分仪法不仅可以提高测定结果的准确性,还可以有效地缩短测定时间,对PVC树脂生产具有指导意义.     

我国PVC电缆料行业现状及对PVC树脂的需求

介绍了我国PVC电缆料行业的现状及线缆业对PVC电缆料的新需求。提出了PVC电缆料行业对分子质量分布均匀的PVC树脂、PVC消光树脂、本体法PVC树脂及高聚合度PVC树脂的需求。     

超低聚合度PVC树脂的生产状况及应用

介绍了超低聚合度PVC树脂的生产状况、应用领域及聚合时应注意的问题,并比较了国内与国外超低聚合度PVC树脂的基本物性.     

悬浮法高聚合度PVC的制备及特性研究

针对以电石为原料用微悬浮法生产糊用聚氯乙烯树脂,讨论了高聚合度PVC树脂的制备要点、树脂质量和特性.表明以低温法或扩链剂法制备高聚合度树脂,工艺简便、质量稳定.     

高型号聚氯乙烯树脂(PVC—SG6)工业试验总结

前言最常用的PVC树脂的聚合度在500～1500之间。通常将平均聚合度在1000以下的PVC树脂称作低聚合度树脂。国家标准中将低聚合度树脂列为PVC—SG6、PVC—SG7型等PVC树脂(一般称为高型号PVC树脂)。高型号PVC树脂具有较好的加工性     

汽车用环保PVC电缆料的研制之一——PVC聚合度的选择

比较了S-1000型、S-1300型和P-2500型PVC树脂的物理性能、耐老化性、力学性能及其电缆料的性能,以及采用不同厂家的1000型PVC树脂生产的绝缘电线的外观质量。结果表明:①高聚合度PVC树脂在老化白度、耐热性、增塑剂吸收量、力学性能等方面都优于普通聚合度PVC树脂,且具有更好的耐老化性及更低的脆化温度;②从力学性能、绝缘性能方面考虑,高聚合度PVC树脂更适合生产电线电缆等软制品,但应注意其熔体流动性大幅下降。     

超低聚合度PVC树脂的生产现状及制备的关键技术

介绍了超低聚合度PVC树脂的生产现状、生产方法、反应机制及配方设计的关键因素。指出超低聚合度PVC树脂具有发展潜力,市场前景广阔。     

Particle features of poly(vinyl chloride) resins prepared by a new heterogeneous polymerization process

The heterogeneous polymerization of vinyl chloride monomer (VCM), with n‐butane as the reaction medium, was used to prepare poly(vinyl chloride) (PVC) resins. The particle features of the resulting resins and the particle formation mechanism of the polymerization process were investigated. The PVC resins prepared by the new polymerization process had a volume‐average particle size comparable to that of suspension PVC resins and a lower number‐average particle size. From scanning electron micrographs, it could be seen that the new PVC resins had a regular particle shape and a smooth surface with no obvious skin. They also had a high porosity. The new PVC resins were composed of individual and loosely aggregated primary particles. The diameter of the primary particles in the top layer of the grains was smaller than that of the primary particles in the center part of the grains. On the basis of the particle features of these PVC resins, a particle formation mechanism for the new polymerization process was proposed. PVC chains precipitate from a VCM/n‐butane mixed medium to form primary aggregates at a very low conversion, and the primary aggregates of the PVC chains aggregate to form primary particles, which further aggregate to form grains. The primary particles and grains grow by the capture of newly formed PVC chains and their primary aggregates and by polymerization occurring inside the aggregates. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 954–958, 2003     

聚氯乙烯树脂吸收增塑剂的影响因素

研究了不同聚合度聚氯乙烯树脂的增塑剂吸收量与吸收时间随聚合度变化规律。结果表明:聚氯乙烯树脂对增塑剂的吸收量随聚合度增大而增大;不同聚合工艺生产的聚氯乙烯树脂由于皮膜结构差异致使对增塑剂的吸收时间差异很大;同一工艺生产的聚合度相同的聚氯乙烯树脂,对增塑剂吸收时间长的塑化能力差。     

超低聚合度PVC树脂研制过程中巯基乙醇添加方式探讨

通过具体的试验数据阐述了巯基乙醇加料方式对PVC树脂主要性能指标（如聚合度等）的影响。结果表明：在适当提高聚合温度（61～64℃）的条件下，分散剂用量0．20％，巯基乙醇用量0．13％时。采取在氯乙烯聚合反应开始时一次流加巯基乙醇3h的方式，所生产的聚合度为400的超低聚合度PVC树脂质量最佳。     

特种聚氯乙烯树脂生产概况

简述了国内外主要特种聚氯乙烯树脂(包括高聚合度PVC树脂、消光PVC树脂、PVC掺混树脂、氯乙烯一醋酸乙烯共聚树脂和氯化PVC树脂)的生产情况。并列举了主要特种PVC树脂的生产厂商、牌号和技术规格。     

不同聚合度PVC树脂的表征和力学性能的研究

采用凝胶渗透色谱仪（ＧＰＣ），差示扫描量热仪（ＤＳＣ）研究不同聚合度ＰＶＣ树脂的分离其分布，玻璃化转变温度（Ｔｇ），考察了加工塑化温度对力学性能的影响。试验结果表明：随着聚合度的提高，ＰＶＣ树脂的分子是增大，分布变宽，Ｔｇ升高，导致材料的加工温度升高，力学性能提高。     

超低聚合度PVC配方的优化

通过调整复合引发剂配比、链转移剂用量,筛选分散剂,选用复合热稳定剂等进一步优化超低聚合度PVC的配方,制得"鱼眼"数少、质量好的聚合度为500、600的PVC.     

Effect of poly(vinyl chloride) resin type in the preparation process of slush powder

During the preparation of the poly(vinyl chloride) (PVC) slush powder, we found that PVC resins obtained by different polymerization methods affected many properties of slush powder and its products. Two types of commercial PVC resins were used for slush powder preparation: mass poly(vinyl chloride) (M‐PVC) and suspension poly(vinyl chloride) (S‐PVC). We used the Haake rheomix test to characterize the absorption of plasticizers into PVC resins, and the results showed that M‐PVC absorbed the plasticizers more quickly than S‐PVC. The fusion behavior of the two slush powders was studied by the thermal plate test and Haake rheomix test, and the results showed that the slush powder of M‐PVC was easier to fuse than that of S‐PVC. The different properties of the two resins and slush powder could be explained by the morphology, average size, and size distribution. Due to the “skin” of the particles' surfaces, the wider size distribution, and the large size of particles, S‐PVC absorbed the plasticizers more slowly and was more difficult to fuse. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3331–3335, 2002