Study On The Modification Of Bismaleimide Resin By PPENS And Benzoxazine

Bismaleimide resin(BDM) possesses excellent properties such as heat resistance, thermal stability, weather ability and dimensional stability. Therefore as the matrix resins of composite materials, BDM has been widely employed in the aerospace, electronic material and automobile industry. But the cured resins have inherent brittleness, poor impact strength and processing behavior because of their high cross-linked density, which greatly limits the application and development. So have to improve toughness of the bismaleimide without sacrificating their original properties push researchers to explore. In this paper the BDM resins is modified by mixing the high-performance thermoplastic poly (aryl ether nitrile sulfone) and thermosetting benzoxazine.Firstly, a kind of poly (aryl ether nitrile sulfone) s containing phthalazinone moiety and a curing-agent monomer were synthesized. Then the BDM/DABP/PPENS blends were prepared by means of melt blending. And the influences of the dosage of the PPENS on the mechanical properties and thermal properties of modified blends were studied. The results revealed that when the blends were added 10-phr PPENS, the unnotched impact strength of the blends reached to 17.4KJ/m2, increasing by 99% compared with the pure BDM/DABP, while the flexural properties maintained without clearly change. Scanning electron microscopy showed that PPENS resins were the dispersed in the blends uniformly, and the blends showed two phase structure, presenting the obvious characteristics of ductile fracture. Although the thermostability of blends was decreasing slightly, the char yield increased. At the same time the processing behavior of the BDM/DABP/PPENS blends was improved after mixing the DABP.Bismaleimide resin was modified by employing benzoxazine (BOZ). Then the BDM/DABP/BOZ blends were prepared by means of melt blending, and non-isothermal DSC tests were conducted to study the curing behavior of blends to determine the curing process. The influences of the different proportion of the BDM/BOZ on the properties of modified blends were studied. The results indicated that when the BDM and BOZ resins ratio of 1:1, the unnotched impact strength of the BDM/DABP/BOZ blends increased by 97%, significantly higher than the pure BDM or BOZ resins with separating curing. What’s more, the tensile strength and modulus of blends were improved, presenting the obvious characteristics of ductile fracture. Meanwhile the BDM/DABP/BOZ blends were homogeneous structure with the addition of the BOZ resin. But the thermostability of BDM/DABP/BOZ blends appeared a decreasing trend and the char yield increased.