Plasticizers are the most commonly used additives for PVC resin, but traditional phthalate plasticizers have certain safety risks. The International Agency for Research on Cancer has listed DEHP as a possible After becoming a carcinogen, a large number of studies on the toxicity of DEHP plasticizers, including toxicity to the mammalian reproductive system, embryos, kidneys, heart, liver and lungs, etc., have shown that DEHP is suspected of being carcinogenic. 

Therefore, research on new non-toxic plasticizers has and development are imminent. This paper uses concentrated sulfuric acid, methanesulfonic acid and activated carbon loaded with methanesulfonic acid as catalysts to prepare cyclohexane-1,2-dicarboxylic acid diisooctyl ester through the esterification reaction of hexahydrophthalic anhydride and isooctyl alcohol. (DH553 plasticizer). The plasticizing properties of PVC were examined and compared with DINCH, TOTM, ATBC and DEHP. The plasticizing properties of DH553 plasticizer mixed with DINCH, TOTM and ATBC were also examined. The following conclusions are drawn: 

(1) The optimal synthesis conditions for the catalytic synthesis of DH553 plasticizer by concentrated sulfuric acid are: the molar ratio of alcohol to anhydride is 2.4:1, the dosage of concentrated sulfuric acid is 0.2% of the mass of the acid anhydride, and the reaction temperature and reaction time are 170°C and 1.5 respectively. h, the esterification rate can reach 98.39%. 

(2) The optimal synthesis conditions for the catalytic synthesis of DH553 plasticizer by methanesulfonic acid are: the molar ratio of alcohol to anhydride is 2.6:1, the dosage of methanesulfonic acid is 0.25% of the mass of the anhydride, the reaction temperature and reaction time are 170°C and 2h respectively, esterification The rate can reach 97.85%. 

(3) Using granular activated carbon loaded with methane sulfonic acid as a catalyst, the optimal synthesis conditions for synthesizing DH553 plasticizer are: the molar ratio of alcoholic anhydride is 2.4:1, the amount of catalyst is 3.5% of the total mass of alcoholic anhydride, the reaction temperature and reaction time are respectively At 160℃ and 3h, the esterification rate can reach 98.25%. 

(4) The molecular structure of the synthesized product was characterized through organic element analysis, infrared spectroscopy, nuclear magnetic resonance, and gas chromatography coupled with mass spectrometry, proving that the obtained product was the target substance cyclohexane-1,2-dicarboxylic acid diisooctyl. The ester was analyzed by GC-MS and the DH553 plasticizer content in the product was 99.18%, of which the cis structure was 97.67%. 

(5) DH553 plasticizer can effectively plasticize PVC, and in terms of mechanical properties, optical properties, volatility and solvent extraction resistance, DH553 plasticizer has similar properties to other plasticizers. After being matched with DINC, TOTM and ATBC, it can interact with each other. make up for their respective shortcomings. DH553 plasticizer can be used as an environmentally friendly and non-toxic plasticizer to replace DEHP. 

(6) The newly synthesized plasticizer DH553 plasticizer is applied to PVC reinforced tracheal intubation, and the obtained physical and chemical properties and toxicological properties meet the relevant requirements.