Study On Poly (Ether-ester) Urethane Elastomers

Polyurethane elastomer (PUE) is a kind of polymer materials with general and excellent properties which are between rubbers and plastics. It often be made into diversified products, such as rubber tires, seals and so on, to be widely used in various fields of national economy because of its outstanding resistance to abrasion, resistance to oil, and remaining high elastic characteristics in a wide rang of hardness, etc.Polyurethane elastomer is generally synthetized by oligomer polyols, isocyanates and chain extenders through the step growth polymerisation reaction. The oligomer polyols mainly include polyether, polyester, polybutadiene, polycarbonate and so on, so polyurethane elastomers can be divided into polyether-type PUE, polyester-type PUE, polycarbonate-type PUE, polyolefin-type PUE,etc. Among them, the applications of the foregoing two are in the majority. Long-term operations practice have proved that polyether-type PUE has poor mechanical performance but good hydrolysis constancy, and the resistance to abrasion and mechanical properties of polyester-type PUE are fine but hydrolysis stability is poor.In view of the above situation, people desperately want to make a kind of polyether-ester polyurethane elastomers that possess the advantages of both polyether-type PUE and polyester-type PUE in a certain way, therefore great efforts have been made by many researchers.In this article, a series of casting poly(ether-ester)urethane elastomers (CPUE) were prepared by the ways of physical blending and chemical modification, and were made for deeply analysis about those related performancesPhysical blending was to blend directly polyether polyol and polyester polyol or to blend two copolymers synthetized by the polyols respectively firstly.And then the polyether-ester CPUE were prepared with the compound after some reactions.However because of the compatibility and reactivity of the two hybrid components were discrepant and for other reasons, the mechanical properties of polyether-ester CPUE often could not get expected requirements.Chemical modification methods refered to preparing the polyether-ester CPUE with the high activity, low unsaturation, narrow distribution of molecular weight polyether-ester polyol which was synthetized by the method as following:using the polyester polyol as the starting agent, in the presence of the double metal catalysts DMC, the epoxy propane occured ring-opening polymerization with the last primary-hydroxyl sealing reaction of epoxy ethane. This paper made key researches about the polyether-ester CPUE prepared by that method.The analysis of Fourier Transform Infrared Spectroscopy (FTIR) showed that that CPUE contained a lot of structure units of polyether-polyester random embedded paragraph. Differential Scanning Calorimetry (DSC) results showed that as the relative content of ether bond in the polyether-ester polyol reducing, the glass transition temperature of the polyether-ester CPUE increased; The performance of resistance to high temperature was studied by the Thermo Gravimetric Analyzer (TGA).It was even more crucial that results of the researches about polyether-ester CPUE showed that, under the same NCO content in copolymer, the mechanical properties of the polyether-ester CPUE are much better than of elastomers based polyether, while hydrolytic stability excels polyester-type elastomers'.This research result will greatly promote the development and production of new polyurethane elastomer materials which combines the excellent mechanical properties of polyester CPUE and good resistance to hydrolysis of polyether CPUE, thus provides for the development and application of new polyurethane materials with theoretical support and guarantee.