Study On The Synthesis And Properties Of Organosilicon/polyurethane/epoxy Resin Terpolymer

Epoxy resins(EP) have eacellent chemical resistance,very good adhesion, excellent mechanical properties and good electric insulation,and have been utilized in many applications such as aircrafts,building,chemistry and civil engineering. Current engineering technolohy demand for good impact strength,low surface energy,which epoxy resins do not generally exhibit.In this paper,in order to improve the toughness of EP,the new method to modify the EP is to untilize polyurethane(PU) and organosilicon,and PU and organosilicon chains grafted in the EP chains,endows the materials with excellent hydrophobic properties and heat resistance.The synthesis,microstructure,dynamic mechanical properties and thermal propertie of modified EP were investigated by FTIR,SEM,DMA,TG and DTG.The mechanical properties,contact angle and water absorption were studied too.Isocyanate terminated polyurethane prepolymer was synthesized with polyaryl polymethylene isocyanate(PAPI) and polypropylene glycol(PPG).The graft polymer PU/EP was synthesized by PU prepolymer and EP.Then adding amino silicon oil,amino oil modified PU/EP were cured by methyl-tetrahydrophalic anhdride(MeTHPA).The results show that the thermal stability of modified EP are improved due to the addition of Si-O chains which delay the thermal degration of matrials;Tg of modified EP is lower than pure EP.When adding amino terminated polydimethysiloxane(ATPDMS),Tg is increasing,because ATPDMS has low molecular weigh,which improves the compatibility of the high molecular weight aminoethylaminopropyl polydimethylsiloxane(AEAPS) with EP,and enhances the graft reaction opportunity,increasing the crosslinking degree of materials.HTPDMS/PU/EP systems were synthesized with PU/EP polymer,amino silane coupling agent(DB792) and hydroxyl terminated polydimethylsiloxane(HTPDMS), which are characterized by FTIR.The mechanical properties,contact angle,frature surface morphology of materials were studied.The results show that the impact strength are remarkly increased,but the tensile strength decreased.When the contents of HTPDMS and PU are 20%and 10%,respectively,the tensile strength is 46.57MPa and the impact strength is 24.317 kJ/m~2,which has increased by 211.8%, compared to EP(7.81 kJ/m~2),and has good integrated mechanical properties.SEM show that the fracture model of both systems are ductlie fracture.The contact angle of testing results show that the contact angles with water of all modified EP augmented with the addition of organosilicon,which are above 95°. The systems have good hydrophobic properties.When the contents of AEAPS and PU are 10%and 20%,respectively,contact angle is up to 106.8°.The systems can be used for low surface energy materials.