双环原酸酯类膨胀单体的合成

SYNTHESIS ABOUT A KIND OF EXPANDING MONOMER WITH BICYCLIC ORTHO ESTER GROUP

通过原酸酯和季戊四醇进行酯交换反应制备了双环原酸酯4-羟甲基-2,6,7-三氧杂二环(2,2,2)辛烷,提出采用原酸酯和季戊四醇在没有催化剂存在时直接反应,可以合成出4-羟甲基-2,6,7-三氧杂二环(2,2,2)辛烷,并研究了这种合成方法的合成机理。首次进行了双环原酸酯4-羟甲基-2,6,7-三氧杂二环(2,2,2)辛烷和大分子未封端聚醚预聚物聚醚的反应,得到了具有较大分子量的两端带有双环原酸酯膨胀基团的长链大分子膨胀单体。

A new kind of bicyclic ortho ester, 4- （hydroxymethyl）-2.6,7-trioxabicyclo[2,2,2] octane was synthesized by the reaction between trimthyl orthoformate and pentaerythritol without catalyst. The mechanism of this reaction was also studied. Some papers proclaimed that the bieyelie ortho ester can be obtained in dioetyl phthalate（DOP） by the reaction between orthoester and pentaerythritol catalyzed by anhydrous p-tolueneeulfonie acid. But our experiments show that this compound cannot be synthesized in the method described above. The ring opening polymerization of bieyelie ortho ester occurs easily in the presence of cationic compounds or high temperature： A kind of expanding monomer with bieyelie ortho ester group was synthesized by the reaction between 4- （hydroxymethyl）-2.6,7-trioxabicyclo [2,2,2-]octane and isoeyanate terminated prepolymer in toluene catalyzed by dibutytin laurate. Which has an average volume increase of 0.43% in the ring opening polymerization initiated by cationic compounds at 130 ℃.