Study On The Synthesis And Curing Bahavior Of Allyl-Functional Benzoxazine

Allyl-functional benzoxazine is synthesized by the reaction of allyl phenol,phenyl amines, and formaldehyde. The reason to research allyl-functionalbenzoxazine is that there are two kinds of reactive functional groups, benzoxazinering and allyl group, in its molecular structure. Modifying bismaleimide resin with itcan not only improve the toughness of bismaleimide, but also keep its goodheat-resistant. And under the heat and/or catalyzer, benzoxazine's ring-openingpolymerization is easy to occur. Therefore, there is no small molecular releasingduring the curing process, and no big change in volume happens. We study the synthesis of allyl phenol compounds firstly in this paper. Duringthe experiment, the synthetic conditions' influence on the final rate of production andreaction time is researched carefully. The result shows that with the nitrogenenvironment and inorganic salt as the catalyzer, the rate of production and reactionefficiency can be improved greatly. Allyl-functional benzoxazine is synthesized with the allyl phenol produced by us.And the product is characterized and deduced by H-NMR, FTIR, MS and DSC. The 1result shows that the composition and structure of product are influenced greatly bydifferent synthetic methods and reaction media. One-step solution method usingtoluene as solvent is preferred because the product have the highest amount ofmonomer compared with the other synthetic methods. In addition, allyl-functionalbenzoxazine has two different kinds of curing mechanisms: the additionpolymerization of double bond and curing reaction of benzoxazine ring. The curing III北京化工大学硕士学位论文temperature of addition polymerization of double bond is close to that of ring-openingpolymerization of benzoxazine ring. The curing behaviors of allyl-functional benzoxazine have been studied in detailsby non-isothermal and dynamic differential scanning calorimetry (DSC). Kissingerequation and Freeman-Carroll equation has been introduced to deal with the data ofDSC analysis. The result shows that Kissinger equation and Freeman-Carroll equationsuit to the copolymer system. And Freeman-Carroll equation shows that the activationenergy and the order of the reaction decrease with the increase of calefactive speed. Benzoxazine has flexible molecule designing property. The synthetic technics ofbenzoxazines with new structures are further studied. And the result of modifyingbismaleimide resin has been researched.