Study Of Polyurethane Elastomers With Reinforcement And Cold Resistance

Polyurethane elastomer(PUE)possesses good mechanical properties,oil resistance and chemical resistance,oxygen resistance and biocompatibility,etc.,due to its special two-phase separation structure,and widely used in the automotive industry,construction,footwear industry,medical and other fields.This paper aims to reinforce the polyurethane elastomer and study the factors that affect its cold resistance,at first,polyether modified MQ silicone was synthesized and used as reinforcing filler to prepare reinforced cross-linked polyurethane elastomer;then the factors that affect the cold resistance of polyurethane elastomer was discussed,including the molecular weight of the soft segments,the type of the soft segments and the modifiers(polyether-modified silicone surfactant and grafted polytetrahyrofuran diol).The main contents are as follows:1.Polyether modified MQ silicone(E-MQ)with relatively narrow molecular weight distribution was synthesized through hydrosilylation reaction of hydrogen-containing MQ resin(H-MQ)and allyl polyether.Then E-MQ was filled in the cross-linked polyurethane elastomer to improve its mechanical properties,the results showed that the prepared polyurethane elastomer exhibited improved mechanical properties and heat resistance.When loading 8% mass of E-MQ,the tensile strength of polyurethane elastomer reached up to20.8Mpa,increased about 22.4% when compared with the pure polyurethane elastomer,the elongation at break was 562%,the tear strength was 82KN/m,the Shore hardness was 82 degrees,the resilience was 48%,glass transition temperature and internal friction did not change significantly.2.The factors that affect the cold resistance of polyurethane elastomer was discussed,including the molecular weight of the soft segments(PTMG1000?PTMG2000?PTMG3000),the type of the soft segment(PTMG?PPG)and the modifiers,polyether-modified silicone surfactant(PSE)and grafted polytetrahydrofuran diol(PTG-L).For polyurethane elastomer with PTMG as soft segment,Tg and ?E' were reduced when increasing the molecular weight of the soft segment,but when the molecular weight w higher than a certain value,its effect on Tg and ?E' became unobvious;Polyurethane elastomer with PTMG as soft segments had a lower Tg and a bigger ?E' when compared with which PPG as soft segments;The microphase separation of the polyurethane elastomer modified with the increse of PSE loading amount,which resulted in the decrease of Tg and the increase of ?E';The crystallization of the polyurethane elastomer modified with PTG-L was significantly reduced,which resulted in slightly increased of Tg,but significantly reduced of ?E';Polyurethane elastomer modified with PSE and PTG-L together obtained better cold resistance in lower Tg and ?E',due to the collective effect of the two modifiers.Polyurethane elastomer modified with PSE had good mechanical properties and heat resistance,the tensile strength was28.1Mpa,the Shore hardness was 88 degrees,the elongation at break was 635%,the tear strength was 73KN/m,the resilience was 62%,the initial temperature of weight loss increased16.8?.