水相悬浮法制备氯化聚氯乙烯新工艺

采用水相悬浮法氯化的一种新工艺以大摩尔质量的SG3型国产聚氯乙烯(PVC)树脂为原料,制备高摩尔质量和高氯含量的氯化聚氯乙烯(CPVC)树脂,考察了工艺条件对CPVC摩尔质量和氯含量的影响。结果表明,氯化后产品CPVC的数均摩尔质量Mn和重均摩尔质量Mw值分别为93 174 g/mol和196 153 g/mol,分别大于PVC的88 487 g/mol和186 607 g/mol;在PVC与盐酸溶液固液比25%,反应温度60℃,1,2-二氯乙烷与PVC质量比0.5,偶氮二异丁腈和紫外光双引发,氯气流量0.4 L/min条件下,产品CPVC氯含量最高可达70.86%。该工艺下SG3型PVC树脂可成功氯化,氯化过程分子链没有发生断裂,氯化效率好,达到国外专用PVC树脂的氯化水平。     

苯乙烯氯化原位接枝改性氯化聚氯乙烯的研究

采用氯化原位接枝技术在聚氯乙烯（PVC）进行氯化反应的同时接枝上各种不同单体．从而制备改性的氯化聚氯乙烯（CPVC）。研究了PVC固相法氯化原位接枝St的规律，讨论了单体苯乙烯（St）加入量、氯含量对产物物理力学性能及流变性能的影响。结果表明：St的加入量为10份时，改性CPVC的屈服强度明显高于空白CPVC的屈服强度，但维卡软化点降低；改性CPVC的屈服强度和维卡软化点均随氟含量增加而增大；St的加入量适当，可以同时提高改性CPVC的屈服强度和冲击性能，降低熔体粘度。     

氯化专用聚氯乙烯树脂颗粒特性的研究——非离子型表面活性剂和链转移剂的影响

水相悬浮法生产氯化聚氯乙烯(CPVC)时,氯化速度和氯化均匀性取决于Cl2在聚氯乙烯(PVC)颗粒中的扩散程度,因而需要有能满足氯化要求的PVC专用树脂。采用以聚乙烯醇(PVA)和羟丙基甲基纤维素(HPMC)为主的复合分散剂,考察Span系列非离子表面活性剂、链转移剂等对PVC颗粒特性的影响。实验结果表明,表面活性剂的加入使PVC树脂增塑剂吸收率、平均粒径和比表面积增大,粒径分布变窄,而表观密度下降;随着链转移剂的加入,PVC树脂增塑剂吸收率、平均粒径和表观密度都增加。     

烯丙基氯含量及其对氯化聚氯乙烯热稳定性能的影响

选取了3种具有相近相对分子质量及其分布的氯化聚氯乙烯（CPVC）树脂,通过固态核磁（13C-NMR）对CPVC树脂的序列结构进行了表征,并对CPVC树脂中烯丙基氯的生成机理进行了分析,在此基础上建立了计算烯丙基氯含量的方法。运用Brabender流变仪研究了3种CPVC树脂的热稳定性。结果表明,相对分子质量及其分布相近的3种CPVC树脂,随着烯丙基氯含量的降低,树脂的热稳定性能越来越好。     

新型气固相法CPVC制备工艺的研究

以经力化学改性的PVC树脂为原料,通过低温等离子体生成自由基Cl.,在气固流化床中制备CPVC,考察了输入电压、体系压力、氯气流量、反应时间、惰性气体等因素对CPVC氯含量的影响,讨论了反应体系温度的控制,并采用扫描电镜对CPVC产物进行了表征。结果表明:①经过力化学改性后的PVC树脂颗粒粒径有较大程度的减小,比表面积增大,且树脂皮膜和结晶区被破坏,有利于氯化反应;②较佳的制备工艺条件为输入电压900V,常压,氯气流量3L/min,反应时间30min,不加入氩气;③输入电压是影响CPVC氯含量的主要因素;④当CPVC的含氯质量分数超过68%后,反应速率快速下降;⑤试验制得的CPVC呈现疏松的不规则雪片状结构,初级粒子、聚集体、亚颗粒等多层次的结构已经完全消失,皮膜也被彻底破坏,比表面积较大。     

增塑剂DOP在软PVC和PVC/ABS共混物中的应用

研究了增塑剂DOP对聚氯乙烯（商品牌号SG-3，SG-5）及PVC／ABS共混物力学和硬度等性质的影响及其机理。结果表明：由于DOP小分子对高分子链的物理隔离作用，当DOP含量高于30％时，随DOP用量的增加，PVC树脂及PVC／ABS的断裂伸长率明显增大，体系的拉伸强度、撕裂强度和硬度等略微下降。     

国内专利精选

<正>一种水相悬浮法CPVC树脂的制备方法:CN106565872A∥张学明(中国石油化工股份有限公司),公开日期:2017-04-19公开了一种水相悬浮法CPVC树脂的制备方法,其特征为:选用特定频率的超声波对PVC树脂进行分散,在该超声波频率下能够保证PVC树脂在水相悬浮体系下分散均匀,同时利用超声波的能效应及化学效应,保证了深度氯化的进行及氯化的均匀性,减少了CPVC树脂结构缺陷。制备的CPVC树脂氯含量及老化白度高、初期着色性好、动态     

聚氯乙烯的悬浮法后氯化工艺

氯化聚氯乙烯(CPVC)是PVC的耐热性改性品种。由于其氯含量大于原PVC,故其使用温度比PVC高35～40℃,制品在沸水中不变形。关于CPVC的性能、应用及加工,前已作过报导(见“聚氯乙烯”1981年No.2.P32;1984年No.1.P58)。将PVC进行后氯化即可得到CPVC,后氯化的方法有溶液法、悬浮法及气相法三种、溶液法所     

氯化聚氯乙烯后处理工艺优化

目前国内外工业化生产氯化聚氯乙烯(CPVC)树脂主要采用水相悬浮法,即,聚氯乙烯树脂在密闭氯化釜中在引发剂作用下与氯气反应生成CPVC,CPVC料浆经脱酸、洗涤、干燥工艺得到CPVC树脂。对氯化后的CPVC料浆后处理工艺进行了优化:1)CPVC料浆脱酸时加入还原剂亚硫酸钠,添加质量分数8%~12%;2)脱酸后的料浆采用蒸馏水洗涤,洗涤时添加乙二胺四乙酸(EDTA),添加质量分数0.05%~0.20%;3)洗涤后进入气流床干燥时添加柠檬酸,添加质量分数8%~11%。结果表明,采用这三种方式优化后,CPVC树脂的热稳定性能和氯含量都得到了提高。     

氯化聚氯乙烯树脂的生产应用及市场前景

氯化聚氯乙烯树脂（CPVC）是聚氯乙烯树脂（PVC）的一种重要改性产品,在化工、建材、电器和黏合剂等领域具有广泛的用途。介绍了氯化聚氯乙烯的性质特点、生产方法及应用情况,并对其市场发展前景作了展望。     

Effect of plasticizers on the thermal decomposition of chlorinated polyvinylchloride

Plasticized samples of chlorinated polyvinylchloride (CPVC) were investigated by using thermogravimetric (TG) analysis and differential scanning calorimetry (DSC). Three different plasticizers were studied, namely, dioctyl phthalate (DOP), alkyldiaryl phosphate ester (Santiciser 2148), and triaryl phosphate ester (Reofos 50). TG experiments in nitrogen showed one major decomposition stage, involving dehydrochlorination, and minor pyrolysis reaction of the hydrocarbon residue. In contrast to the three stages previously reported to occur in the nonplasticized‐stabilized CPVC, TG analyses in air showed two distinctive decomposition stages for the plasticized CPVC samples. The DOP system provided a suggestion of a third stage. The first decomposition stage was due not only to the loss of all the chlorine present, but also to loss of the plasticizer or its decomposition products. The second decomposition stage was mostly due to char oxidation, the char being formed almost exclusively from the DCE and VDC units in CPVC polymer. DSC results showed that in the presence of nitrogen, there was no significant plasticizer effect on the thermal decomposition behavior of CPVC up to about 330°C, while in air the DSC traces also show no significant differences below 400°C. The two phosphate plasticizers showed no significant differences in their effect on the thermal decomposition behavior of CPVC under the same experimental conditions. It is believed that P₂O₅ and polyphosphoric acid are among the main constituents of the residua. These would impart a protective glassy surface to the char. This will facilitate effective flame retardant action. This preliminary conclusion is based on the premise that the more stable the char layers are, the more resilient will be the protective layer, and consequently, the better the flame retardant effect. J. VINYL ADDIT. TECHNOL., 11:21–27, 2005. © 2005 Society of Plastics Engineers     

PVC-C/PVC共混材料的性能研究

采用氯化聚乙烯（CPE）对氯化聚氯乙烯（PVC—C）进行抗冲改性，将改性后的PVC—C与PVC进行共混，研究了PVC-C／PVC配比对PVC-C／PVC共混物力学性能、耐热性能及流变形能的影响。结果表明，PVC—C／PVC共混物的维卡软化点随PVC—C的用量增加而上升，在50／50（质量比）处有一拐点，大于50／50时上升更快些。共混物的拉伸强度、弯曲强度和熔体黏度随PVC—C用量的增加而提高；混物中随PVC—C用量增加，塑化时间缩短，塑化能力增强，而冲击强度和断裂伸长率却随PVC—C用量增加而下降。共平衡转矩增加。     

水相法氯化聚氯乙烯树脂分子质量的控制

研究了氯化聚氯乙烯树脂（CPVC）平均分子质量与加工耐热稳定性的关系，确定了水相悬浮氯化过程中影响CPVC树脂分子质量的主要因素。结果表明，制备合格的CPVC树脂，除受PVC原料影响外，选择合适的引发剂及其用量、通氯速率可控制CPVC的平均分子质量，氯化反应温度在一定程度上也影响着CPVC树脂的平均分子质量。     

Degradation of chlorinated polyethylene—III: Effect of additives on dehydrochlorination and oxygen absorption

Degradation of chlorinated polymers takes place via two simultaneous reactions; namely, dehydrochlorination and oxygen absorption. The dehydrochlorination and oxygen absorption of five grades of chlorinated polyenthylenes were studied at temperatures varying between 120 and 180°C. The chlorinated polyethylene grades varied in both molecular weight and chlorine content, the latter being in the range of 24.0 to 45.2 percent chlorine. Dehydrochlorination measurements on the pure polymers in both nitrogen and oxygen atmospheres showed that the rate of dehydrochlorination increases with an increase in the degree of chlorination of the polymer. The oxygen absorption rate, however, showed a decrease with higher chlorine content of the polymer. Dehydrochlorination and oxygen absorption studies were also carried out on chlorinated polyethylene containing dehydrochlorination stabilizers, antioxidants, antimony oxide, and other metal salts and metal oxides. Retardation of both oxygen absorption and dehydrochlorination was observed in the presence of antioxidants. More significant, however, was the observed action of some dehydrochlorination stabilizers as efficient antioxidants in the polymer.     

Effects of postchlorination on key product and processing properties of PVC

The behavior of PVC resins has been shown to change dramatically when postchlorinated from 57 to 70 percent chlorine. Many of these changes are beneficial: heat resistance, thermoformability, and combustion properties are improved to an extent that opens new market opportunities for properly formulated chlorinated PVC (CPVC) materials. Sharply increasing melt viscosity also results from increasing chlorine content, creating the need for compounding and processing expertise differing from that for rigid PVC. The fact that such expertise has been developed, and is constantly being improved, is expanding the use of CPVC.     

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。