Study On The Properties Of Digiycidyl Ether Of Bisphenol Propene (DGEBP) Modified With Liquid NBR

As a kind of important thermosetting polymer material, epoxy resin has been widely used in many industrial areas such as adhesives, coatings, electronics and aerospace owing to high strength, high bonding property, electric insulation and corrosion resistance. With the development of science and technology, lots of novel epoxy resins have been prepared to meet wider application. However, cured epoxy resins are often brittle and have internal stress, and toughening of the resin was and is still the hotpot of epoxy industry.A novel bisphenol epoxy resin with double bonds as side group (DGEBP) has been synthesized in the lab and then the resin was toughened with liquid NBR, which was characterized by DMTA,SEM,IR. The physical properties and microscopic phase structure were characterized and the compatibility of epoxy resin and liquid NBR was analyzed thoroughly.Results showed that the DGEBP had better compatibility with liquid NBR than E-51. The system of/DDM was transparent after cured with only one Tg in contrast with that the system of E-51/LNBR/DDM was not transparent with two Tg. When cured by D230, both E-51/LNBR system and DGEBP/LNBR system were not transparent while the miscibility of DGEBP/LNBR was better. The affection of DGEBP on the miscibility of E-51/LNBR was studied by DMA and TEM. The glass transition temperature and microscopic phase morphology was varied regularly with the load of vinyl side chain epoxy resin. With the increasing content of DGEBP, the Tg of rubber-rich phase and resin-rich phase was close up. When cured by curing agent DDM, the rubber-rich phase disappeared at the ratio of DGEBP/E-51 above 1:1.The epoxy value of DGEBP was measured at 0.34 and its mechanical properties were weaker than that of E-51, but it can improve the mechanical properties of E-51/LNBR system. The tensile strength of DGEBP/E-51/NBR system was 11.9% higher than that of E-51/NBR system when the ratio of DGEBP and E-51 was 4/6 and NBR concentration was 20%, wt. Similarly, the bending strength and elongation at break were 31.3% and 14.8% higher respectively. Furthermore, the glass transition temperature of DGEBP/E-51/NBR system varied according to the concentration of DGEBP.The mechanical properties and microscopic phase structure of DGEBP/S/NBR system was different from the system without sulfur, which could be in contributed to the reaction of sulfur to double bond in both DGEBP and NBR. FTIR results showed that the microscopic phase structure differed with different curing agents.As a whole, the thesis developed a new method to improve the compatibility of epoxy resin and NBR system.