Prepapration And Properties Of Novel Water-soluble Benzoxazine/Preparation Of POSS Modifier With Polyurethane Structure

Polybenzoxazines,as a novel type of phenolic resin,have the advantages of the traditional phenolic resins,such as good thermal stability,mechanical strength,excellent electrical property,and outstanding fame retardance.In addition,they also provide unique characteristics like molecular design flexibility,nearly zero shrinkage,release of no byproducts upon curing,curing without using acid or basic catalysts etc.However,there are still some shortcomings for polybenzoxazines including much higher curing temperature,brittleness and not good film forming ability.At this moment,many novel benzoxazine monomers or precursors have been developed and most of the researches have been focused on how to further improve the thermal stability or how to reduce the curing temperature.To surmount the current conventional research,new fields for polybenzoxazine should be explored.So it will be a very important research direction in the future about how to develop new functional polybenzoxazines.The unsaturated polyester resin is an important thermosetting resin in modern plastics industry,and it has been applied in many fields because of its diversified products.Polyurethane modified unsaturated polyester resin showed better mechanical properties,including excellent flexibility and high impact and damage tolerance.Introducing POSS group can enhance the thermal and mechanical properties of unsaturated polyester resin.So it is very important to develop new modifiers,in order to meet the diversified applications of unsaturated polyester resin.In this thesis,we considered to develop novel water-soluble benzoxazine,which was successfully prepared by three-step method with the Salicylic aldehyde,formaldehyde and 3,5-bis(aminomethyl)methyl benzoate.The properties of the relative polybenzoxazines were also investigated.In addition,a new unsaturated polyester resin modifier was successfully synthesized,in which the structure of POSS group and polyurethane were both introduced.The research work mainly consists of the following two parts:(1)For the first time,3,5-bis(aminomethyl)methyl benzoate was used as the amine source for the synthesis of the benzoxazine,and novel water soluble benzoxazine P-bamb was prepared by the three-step method.The introduced Ester group can be rapidly hydrolyzed into salt in alkaline condition,which wound provide P-bamb water soluble.PolyP-bamb show good film properties and also had excellent heat resistance.The weight loss temperature of 10%for polyP-bamb was 408℃ and the char yield was 55%at 800 ℃.(3)The polyether-terminated or acrylate-terminated POSS modifier with polyurethane structure was successfully prepared,which were characterized by FTIR and 1H NMR.