Study Of UV Curing Of Bismaleimide

Bismaleimide (BMI) is one kind of typical high performance thermosetting resin,which has been considered as one kind of the most competitive structural/functional materials, and playing more and more important role in many industries including defense and military, electronic information and transportation. The biggest drawback of BMI is its high curing temperature and long curing time, causing big residual stress in cured network and thus declining the performance of the material. Therefore, how to overcome the disadvantage has been the main subject on investigations of BMI.Compared to other curing methods, ultra-violet (UV) curing technology exhibits many advantages such as fast curing speed, high production efficiency, environmental protection, energy-saving and low cost as well as the possible end-usage in outdoors. Therefore, as the "new technology of green industries in the 21st century", UV curing has been received wide attentions in both academic and industrial fields. It is no doubt that there are important theoretical significance and application value in investigating UV-curable BMI resin. This thesis aims to investigate the possibility to develop UV-curable BMI resin.In this thesis, N,N'-4,4'-diphenylmethane bismaleimide(BDM)/1,6-hexamethylene diacrylate(HDDA)/photoinitiator system was prepared, the UV-curable reactivity of the system was characterized by infrared spectroscopy, gel content and dry time. The influences of the contents of photoinitiator and BDM on UV curing and thermal stability of the system were investigated. Results show that in order to achieve UV curing, BDM/HDDA system needs to be carried out with photoinitiators, 2,4,6-trimethyl benzoyl-diphenyl phosphate oxidation (TPO) shows more effective role than benzoin ethyl ether (BE), and benzophenone-triethanolamine (BP-TEA) system. The influence of photoinitiators on the UV-curability and UV curing efficiency of BDM/styrene (St) system was studied, and the influence of BDM content on the UV curing of the BDM/St system was also investigated. Results show that BDM/St system is UV-curable with radical cleavage-type photoinitiator, and TPO has bigger induced effect than BE.The UV-curable BDM/4-hydroxyl butyl vinyl ether (HBVE) system was prepared. The UV curing of BDM/HBVE system is affected by the type and content of photoinitiators as well as the content of BDM. It shows that BDM/HBVE system is UV-curable with radical cleavage-type photoinitiator. If the content of BDM is too low, BDM/HBVE is unable to reach dry. Under the same conditions, the higher the content of BDM, the greater the gel content is.