The Study On Glass-Fiber Reinforced Phenolic Resin Nanocomposites Cured Without Ammounia

Phenolic resin has been widely used in electrical and electronic appliance, automotive and other industry fields due to its excellent electric, thermal and mechanical performance. However, phenolic plastic (novolac) prepared with two-step method is mostly cured with HTMA and this curing process will release ammonia from HTMA, which will corrode the copper or brass parts. It is very necessary to develop a novel phenolic plastic without ammonia after curing, which it is mostly depended on importation now. The dissertation emphasizes on preparing a novel phenolic plastic cured without ammonia and aims at enhance the thermal and mechanical performance.The paper consists of the following parts: (1) synthesis of a novel resol with dibenzyl ether bond; (2) preparation of the phenolic resin/layered silicates nanocomposites (RPLSN) and investigating the melt intercalation and curing behavior; (3) discussing mechanical properties and its related influence factor.The synthesis conditions of the resol with dibenzyl ether bond are discussed in the first section and it is characterized by FT-IR and gel-time test. The results show that the gel time of the resol prepared in this paper is much longer than that of resol catalyzed with normal alkali such as ammonia and it is more stable when temperature is under 160 ; while temperature exceeds 160 , it cures very fast.Secondly, the intercalation and exfoliation behavior of two layered silicates modified by organic cation (DK1 and DK3) with the resol under different conditions is investigated. It is found that the intercalated structure of DK3 is preserved and exfoliated in cured RPLSN, while the resol intercalated in DK1 is deintercalated when it is cured. It is suggested that DK3 intercalated in the resol is more stable in the curing process than DK1. Conclusively, organic modifier used for layered silicate plays an important role in determining the stable nanostructure.Finally, glass-fiber reinforced phenolic nanocomposite is prepared and its mechanical properties are investigated. The results indicate that good mechanical properties are obtained under condition that the content of DK3 is 3wt% in resin, resin is consisted of the ratio of 3:7 (novolac: resol) and proportion of resin with reinforcer is 35/65.