Jubsilp Chanchira, Asawakosinchai Aran, Mora Phattarin, Saramas Duangporn, Rimdusit Sarawut
Department of Chemical Engineering, Faculty of Engineering, Srinakharinwirot University, Nakhon Nayok 26120, Thailand.
Research Unit in Polymeric Materials for Medical Practice Devices, Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University, Pathumwan, Bangkok 10330, Thailand.
Polymers (Basel). 2021 Dec 30;14(1):133. doi: 10.3390/polym14010133.
In this paper, the effects of organic based stabilizers (OBS) are investigated and compared with traditional lead (Pb) and calcium zinc (CaZn) heat stabilizers regarding their processability, mechanical property, and thermal degradation behaviors in rigid PVC pipe applications. In addition, the effects of repeated processing cycles on the degree of gelation and the impact strength of the PVC/OBS, PVC/CaZn, and PVC/Pb are also examined. A repeated processing cycle of those three types of the heat stabilizers up to four cycles was found to increase the degree of gelation and proved no significant effect on the impact strength and heat resistance of the resulting PVC samples. The OBS showed a positive effect on preventing the autocatalytic-typed thermal degradation of the PVC samples. This leads to a longer retention time for the initial color change of the PVC/OBS compared to PVC/Pb or PVC/CaZn systems. This characteristic was related to a more uniform fusion behavior of the PVC/OBS, i.e., the lowest gelation speed and the longest fusion time. The non-isothermal kinetic parameter determined by the Kissinger and Flynn-Wall-Ozawa methods of the dehydrochlorination stage of the PVC/OBS was in satisfactory agreement and continued to compare with the PVC/Pb and PVC/CaZn systems. The results indicated that the OBS might decrease the dehydrochlorination rate of PVC, implying that PVC/OBS was more stable than PVC/Pb and PVC/CaZn systems.
本文研究了有机基稳定剂（OBS）的效果，并将其与传统的铅（Pb）和钙锌（CaZn）热稳定剂在硬质聚氯乙烯（PVC）管材应用中的加工性能、机械性能和热降解行为方面进行了比较。此外，还考察了重复加工循环对PVC/OBS、PVC/CaZn和PVC/Pb体系凝胶化程度和冲击强度的影响。发现这三种热稳定剂重复加工循环至四个循环会提高凝胶化程度，且对所得PVC样品的冲击强度和耐热性无显著影响。OBS对防止PVC样品的自催化型热降解有积极作用。与PVC/Pb或PVC/CaZn体系相比，这使得PVC/OBS初始颜色变化的保留时间更长。这一特性与PVC/OBS更均匀的熔融行为有关，即最低的凝胶化速度和最长的熔融时间。通过基辛格法和弗林-沃尔-小泽法测定的PVC/OBS脱氯化氢阶段的非等温动力学参数吻合良好，并继续与PVC/Pb和PVC/CaZn体系进行比较。结果表明，OBS可能会降低PVC的脱氯化氢速率，这意味着PVC/OBS比PVC/Pb和PVC/CaZn体系更稳定。
