The Curing Of The Carboxyl-terminated Liquid Fluorine Rubber

Fluorine rubber refers to the main chain or side chain carbon atoms containing fluorine atoms in a high molecular elastomer,it has good heat resistance,oil resistance,oxidation resistance and chemical resistance.It is a self-dying Functional rubber,which has a wide range of applications in the defense,petrochemical,aerospace and other fields.Traditional fluorine rubber is basically in solid form,through the molding or extrusion molding parts,by the mold size,shape and other restrictions,the traditional solid fluorine rubber can not meet all the application requirements,and it has the poor processing performance.Based on this situation,liquid fluorine rubber came into being.Liquid fluorine rubber is a low molecular weight fluorocopolymer,which is a non-crystalline copolymer,Tg below 0 ?.In order to prevent it from flowing at high temperatures and to maintain elasticity during use,it must be cured and crosslinked,so it is important to study the curing of liquid fluorine rubber.In this paper,the curing performance of the carboxyl-terminated liquid fluorine rubber was studied on the basis of the successful synthesis of the terminal carboxyl liquid fluorine rubber in the laboratory.In this paper,HDI trimer and epoxy resin are used to solidify the carboxyl-terminated liquid fluorine rubber.The curing process is explored by IR and DSC.The physical and mechanical properties,the solvent resistance and the heat resistance of the cured product are studied.Through the experimental study,this paper draws the following conclusions.The results show that the carboxyl group liquid fluorine rubber and HDI trimer can cure at 94 ? by IR and DSC.The aim of the experiment is to determine the best of HDI trimer solidified carboxyl-terminated liquid fluorine rubber.Curing conditions,and the effect of the addition amount of curing agent on the mechanical properties of the cured product and the solvent resistance are investigated.The results show that when the ratio of isocyanate group to carboxyl group is 1.20,the performance is the best,and it is proved that the cured product had good solvent resistance.The results show that the carboxyl group liquid fluorine rubber and epoxy resin can cure at 103 ? by IR and DSC.The aim of the experiment is to determine the best of epoxy resin solidified carboxyl-terminated liquid fluorine rubber.And the effect of the addition amount of curing agent on the mechanical properties of the cured product and the effect of solvent resistance are investigated.The results show that when the ratio of epoxy group to carboxyl group is 2.0,the mechanical properties are the best and the cured product has good solvent resistance.