Composite catalyst of heteropolyacid ammonium salt, (NH₄)₃PW₁₂O₄₀, and SiO₂ was prepared by sol–gel method. The resultant catalyst ((NH₄)₃PW₁₂O₄₀-SiO₂, 3.38wt%) having W/Si molar ratio of 2/8 enabled to proceed ring-opening polymerizations of tetrahydrofuran (THF), ε-caprolactone (CL), and glycidyl phenyl ether (GPE) to give the corresponding poly(THF), poly(CL), and poly(GPE) having number-average molecular weights (M_n) of 6610, 4010, and 2370 with polydispersity index (M_w/M_n) of 1.57, 1.36, and 1.49 in 24%, 88%, and 59% yields, respectively. Matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) spectra of poly(CL) and poly(GPE) exhibited that Brønsted acid induced from (NH₄)₃PW₁₂O₄₀-SiO₂ is the only one species that initiates the polymerization.

采用溶胶-凝胶法制备了杂多酸铵盐，（NH ₄）₃ PW ₁₂ O ₄₀和SiO _2的复合催化剂。将得到的催化剂（（NH ₄）₃ PW ₁₂ ö ₄₀ -SiO ₂，3.38wt％），其具有W /硅的2/8摩尔比能够继续进行的四氢呋喃（THF），ε己内酯的开环聚合（CL）和缩水甘油基苯基醚（GPE），得到相应的聚（THF），聚（CL）和聚（GPE），其数均分子量（M _n）为6610、4010和2370，且多分散指数（M _w / M _n）分别以24％，88％和59％的收益率分别为1.57、1.36和1.49）。聚（CL）和聚（GPE）的基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）光谱显示，由（NH ₄）₃ PW ₁₂ O ₄₀ -SiO ₂诱导的布朗斯台德酸是唯一的一种引发聚合反应的物种。