钒钼协同作用下杂多酸催化阻聚甲基丙烯酸甲酯

Catalytic Inhibition of Heteropoly Acid on Polymerization of Methyl Methacrylate Affected by the Synergsic Action of Vanadium and Molybdenum

利用一锅法制备了Dawson型钨磷酸和钼钒磷酸,并用红外光谱和X-射线衍射表征了其结构.采用沸腾法研究了合成的杂多酸对甲基丙烯酸甲酯(MMA)的催化阻聚性能,考察了杂多酸结构、杂多酸用量和反应温度等因素对MMA本体聚合反应的影响.结果表明:钒钼元素在杂多酸催化阻聚MMA的反应中具有明显的协同作用,而且,杂多酸对MMA的催化阻聚作用随钒原子数的增加而增强,杂多酸的用量和反应温度对MMA自聚反应的速率影响较大.在过氧化苯甲酰(BPO)为0.04 g,MMA为10 mL,H9P2Mo15V3O62质量为MMA的0.06%,反应温度为101.2℃或H9P2Mo15V3O62质量为MMA的0.03%,反应温度为89.4℃时,MMA自聚反应被抑制.与传统和常用酚阻聚剂相比,Dawson型钼钒磷酸具有阻聚效果好、后处理简单、无腐蚀和污染问题等优点,能够作为MMA的阻聚剂使用.

The Dawson-type molybdophosphoric and molybdovanadophosphoric acids were synthesized via the one- pot process and characterized by IR and X-ray power diffraction. The inhibition effects of the heteropoly acids for the polymerization of methyl methacrylate （MMA） were investigated by ebullition method and effects of the hetero- poly acid structure, H9P2Mo15V3O62 dosage and reaction temperature on the reaction were tested. The results showed that the catalytic Inhibitions of heteropoly acid on the polymerization of MMA were affected by the synergsic action of vanadium and molybdenum. Moreover, the inhibition effects of the heteropoly acid for the polymerization of MMA increased with the increasing of the amounts of vanadium in the heteropolyacid molecules. The dosage of the heteropoly acid and the reaction temperature had significant effect on the rate of MMA polymerization. The poly- merizations were prohibited when the dosage of benzoyl peroxide （BPO） was 0.04 g, MMA was 10 mL, mass ratio ofH9P2Mo15V3O62 to MMA was 6 ： 10 000 g, the reaction temperature was 101. 2 ℃ or mass ratio ofH9P2Mo15V3O62 tto MMA was 3 ： 10 000 g, reaction temperature was 89.4 ℃. Compared with using phenol as cat- alyst, the catalyst can be used for inhibition of the polymerization of MMA characterized by process simplification, higher efficiency and no corrosion for facilities have been achieved.