| In this study, with triethylamine as acid acceptor, hyperbranched polyester P501, P502and P503were prepared by reaction between hyperbranched polyester polyol P500and acetyl chloride, pentoyl chloride and octanoyl chloride respectively. The optimum preparation process conditions were obtained through experiments:the mole ratio of P500to triethylamine to chloride was1:22:20, the reaction temperature was0℃, and reaction time was half an hour.The main properties of every hyperbranched polyester plasticizers, including hydroxyl functionality, chromaticity, TG, relative viscosity and heating loss, were measured by physical and chemical methods. Products were characterized by infrared spectrum and gel permeation chromatography, which proved the existence of characteristic absorption peaks of hyperbranched polyester.The application performance of hyperbranched polyester plasticizers, including the compatibility with PVC, hardness, thermal evaporation rate of plasticized PVC and plasticizer extraction resistance were tested and were compared with single size plasticizers such as DEHP. Although hyperbranched polyester plasticizers have lower plasticizing efficiency compared with DEHP, the plasticizers exhibit good withstand volatilization properties, withstand extraction properties and good compatibility. But hyperbranched polyester plasticizers have low esterification rate and exhibited worse plasticizing efficiency than DEHP. A large number of hydroxyl groups in the hyperbranched polyester plasticizer may account for this result.Besides, the synthetized hyperbranched polyester plasticizers were compounded with DEHP and their performance tests were carried out. The results showed that evaporation rate and extraction rate of the plasticized samples are greatly reduced, but the hardness and tensile testing of the plasticized samples has no significant change. It indicated that hyperbranched polyester plasticizer could make up the shortcomings of DEHP. |
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