ISSN: 1003-6326
CN: 43-1239/TG

Vol. 12    No. 5    October 2002

Synthesis of antimony tris
(mercaptoethyl carboxylates) 
as thermal stabilizer for polyvinyl chloride
SHU Wan-yin(舒万艮), LIU You-nian(刘又年), CHEN Qi-yuan(陈启元)
(College of Chemistry and Chemical Engineering,
 Central South University, Changsha 410083, China
Abstract: A novel type of thermal stabilizers—antimony tris(mercaptoethyl carboxylates) (Sb(SCH2CH2OOCR) 3), was synthesized from carboxylic acid, antimony trioxide and 2-mercaptoethanol in two steps. The experimental results show that the molar ratio of carboxylic acid to antimony tris(2-hydroxyethyl mercaptide) is 1.2, when adding 0.6% tetra-n-butyl titanate as catalyst and xylene as isotropic solvent, heating and refluxing for about 2~4h. The thermal stability was measured by heat-aging oven test. The thermal stability time is about 8~40min(at 200℃) when adding 2% tetra-n-butyl titanate in polyvinyl chloride(PVC). Among these stabilizers, antimony tris(mercaptoethyl stearate) has best thermal stability. Its thermal stability is better than that of Ca-Zn complex and basic lead stabilizers, and equal to that of organotin. In addition, the stabilization mechanism of this kind of stabilizers for PVC was discussed briefly.
Key words:  PVC thermal stabilizer; antimony mercaptan; synthesis; thermal stability 
Superintended by The China Association for Science and Technology (CAST)
Sponsored by The Nonferrous Metals Society of China (NFSOC)
Managed by Central South University (CSU)