Study On Phase Structure And Mechanical Properties Of Liquid Rubber Terminated By Amidogen Enhanced With Epoxy Resin

Amine-terminated butadiene acrylonitrile (ATBN) was applied as curing agents for diglycidyl ether of bisphenol A epoxy resin without any accelerating agent. ATBN weight percentage of59-82wt%was used, so that the soft ATBN domains in the cured samples formed a continuous phase, while the hard epoxy domains formed a discontinuous phase as irregular particles. Mechanical properties were tested in the means of strain-stress and adhesive strength. The results showed that the ATBN/Epoxy samples had excellent toughness at temperatures above the flexible segment glass transition temperature (Tg1). However, adhesive strength of the annealed sample decreased dramatically when the testing temperature was close to the rigid segment glass transition temperature (Tg2).It was observed that Tg2decreased and phase separation became weaker after annealing at150℃. Real-time Fourier transform infrared (FTIR) measurement indicated that this phenomenon was related to the disassociation of hydrogen bonding within the hard domain caused by the high temperature annealing. It was confirmed by transmission electronic microscope (TEM) test with clear images of the original and annealed samples.On the basis of the above study about phase structure and mechanical properties of ATBN/Epoxy elastomer, Amine-terminated poly-butadiene (ATPB) was applied as curing agents for epoxy resin. Similarly, ATPB domains in the cured samples formed a continuous phase, with weight percentage from59to82wt%. ATBN/Epoxy elastomers were used as control groups. DMA results showed that ATPB/Epoxy elastomers had more stable phase structure than ATBN/Epoxy, which was maintained well even after150℃annealing. Meanwhile, the degree of phase separation in ATPB/Epoxy elastomer was remarkable than that in ATBN/Epoxy. Mechanical properties were tested in the means of strain-stress, adhesive strength and impact strength. The results showed that the cryogenic properties were better and they had larger breaking elongation and better toughness even under lower temperature. Both ATBN/Epoxy and ATPB/Epoxy samples had relatively higher adhesive strength on different substrates, such as stainless steel, fiber reinforced plastics (FRP), tetrafluoroethylene and styrene-butadiene rubber (SBR).