关键词: FONT-SIZE: 10.5pt, mso-bidi-font-size: 11.0pt, mso-ascii-font-family: Calibri, mso-ascii-theme-font: minor-latin, mso-fareast-theme-font: minor-fareast, mso-bidi-font-family: 宋体, mso-ansi-language: EN-US, mso-fareast-language: ZH-CN, mso-bidi-language: AR-SA">磷钨酸；βFONT-SIZE: 10.5pt, mso-bidi-font-size: 11.0pt, mso-ascii-theme-font: minor-latin, mso-fareast-theme-font: minor-fareast, mso-bidi-font-family: 宋体, mso-ansi-language: EN-US, mso-fareast-language: ZH-CN, mso-bidi-language: AR-SA, mso-fareast-font-family: 宋体, mso-hansi-font-family: 宋体" lang=EN-US>-FONT-SIZE: 10.5pt, mso-bidi-font-size: 11.0pt, mso-ascii-font-family: Calibri, mso-ascii-theme-font: minor-latin, mso-fareast-theme-font: minor-fareast, mso-bidi-font-family: 宋体, mso-ansi-language: EN-US, mso-fareast-language: ZH-CN, mso-bidi-language: AR-SA">蒎烯；阳离子聚合

Abstract:

β-Pinene polymerization is usually initiated with cationic catalysts.Lewis acids such as AlCl₃, BF₃,TiCl₄ are the most effective catalysts and therefore commonly used in the commercial process.But the halides can cause severe problems of environmental hazards and poison hydrogenation catalysts in later hydrogenation process.In addition, dark color of polymer obtained limits its application in many areas in which light color or colorless resins are required.Keggin heteropolyacids (HPAs) are of some advantages such as high catalytic activity, high thermal and oxidative stability, non-corrosion and non-polluting to environment,and have been paid more and more attention in organic synthesis and the petrochemical industry.12-Phosphotungstic acid (PW₁₂) catalyst is explored for β-pinene cationic polymerization in this paper.The catalyst and polymer obtained are characterized by 1H NMR, XPS, XRD, FTIR, GPC and GC-MS, and it is shown that the crystal structure of the heteropolyanion is not destroyed during the reaction.The protons dissociating from the catalyst play an important role in the polymerization.The PW₁₂ is both polymerization initiator and the counter-anion of the growing cation center.The effect of solvent,calcination temperature and time, reaction temperature and time, and the dosage of catalyst on the catalytic performance are studied too.Under optimum reaction conditions, the overall conversion of β-pinene is up to 97.37%,and the polymer yield is 60.85% and its average number molecular weight is about 1170.

Key words: FONT-SIZE: 10.5pt, mso-bidi-font-size: 11.0pt, mso-ascii-font-family: Calibri, mso-ascii-theme-font: minor-latin, mso-fareast-theme-font: minor-fareast, mso-bidi-font-family: 宋体, mso-ansi-language: EN-US, mso-fareast-language: ZH-CN, mso-bidi-language: AR-SA">磷钨酸；βFONT-SIZE: 10.5pt, mso-bidi-font-size: 11.0pt, mso-ascii-theme-font: minor-latin, mso-fareast-theme-font: minor-fareast, mso-bidi-font-family: 宋体, mso-ansi-language: EN-US, mso-fareast-language: ZH-CN, mso-bidi-language: AR-SA, mso-fareast-font-family: 宋体, mso-hansi-font-family: 宋体" lang=EN-US>-FONT-SIZE: 10.5pt, mso-bidi-font-size: 11.0pt, mso-ascii-font-family: Calibri, mso-ascii-theme-font: minor-latin, mso-fareast-theme-font: minor-fareast, mso-bidi-font-family: 宋体, mso-ansi-language: EN-US, mso-fareast-language: ZH-CN, mso-bidi-language: AR-SA">蒎烯；阳离子聚合