Synthesis Of A New Plasticizer And Its Application In Pvc Medical Products

A plasticizer is an additive which PVC consumes the largest amount of. But the traditional plasticizers of phthalates are found to have potential toxicity to human health in the last decades. After the International Agency for Research on Cancer classifing DEHP as possible carcinogenic to humans, numerous experiments proved it to have a carcinogenic suspicion through examing the reproductive toxicity, as well as the embryotoxicity, nephrotoxicity, pulmonary toxicity, cardiotoxicity, and hepatotoxicity of DEHP in mammals. The study and development of new non-toxic and biodegradable plasticizers have caused increasing attention of the society.In this article, concentrated sulfuric acid, methanesulfonic acid and activated carbon supported methanesulfonic acid were used as catalysts for the esterification reaction between hexahydrophthalic anhydride (HHPA) and iso-octanol to synthesize di(2-ethylhexyl)-1,2-cyclohexane dicarboxylate (DEHCH). And the plasticizing performance of the synthesized DEHCH was also investigated. Its plasticizing performance was in contrast with those of DINCH, TOTM, ATBC and DEHP. The conclusions are as follows:(1) The optimal reaction conditions catalyzed by concentrated sulfuric acid were as follows:the molar ratio of iso-octanol to HHPA was2.4:1, catalyst amount was0.2%of the mass of HHPA, reaction temperature was170℃, and reaction time was1.5h. The esterification yield was98.39%.(2) The optimal reaction conditions catalyzed by methanesulfonic acid were as follows:the molar ratio of iso-octanol to HHPA was2.6:1, catalyst content was0.25%of the mass of anhydride, reaction time was2h, and reaction temperature was170℃. The esterification yield was97.85%.(3) The optimal reaction conditions catalyzed by activated carbon supported methanesulfonic acid were as follows:the molar ratio of iso-octanol to HHPA was2.4:1, catalyst content was3.5%of the mass of iso-octanol and anhydride, reaction time was3h, and reaction temperature was160℃. The esterification yield was98.25%.(4) The functional groups analysis of DEHCH was conducted by using organic elemental analysis, FTIR,1HNMR and GC-MS. The content of DEHCH was99.18%of the mass of the reaction products. And cis-cyclohexane-1,2-dicarboxylic esters accounted for97.67%.(5) DEHCH is an efficient plasticizer for PVC. It has a similar performance with DINCH, TOTM, ATBC and DEHP at mechanical properties, transparency, volatility and migration stability. When DEHCH was used with other plasticizers, they could make up for their deficiencies for each other. DEHCH can be an alternative plasticizer for DEHP.(6) The new synthesized plasticizer DEHCH was used in reinforced tracheal intubation. The physical, chemical and toxicological properties all meet the requirements.