Synthesis of vinyl end‐capped polydimethylsiloxane by ring opening polymerization of octamethylcyclotetrasiloxane (D4) catalyzed by rare earth solid super acid SO42‐/TiO2/Ln3+. Issue 2 (13th May 2013)

• Record Type: Journal Article
• Authors: Yang, Xiongfa; Shao, Qian; Fang, Qing; Yang, Linlin; Cao, Cheng; Ren, Zhaohui; Wu, Lianbin; Lai, Guoqiao; Han, Gaorong
• Is Part Of: Polymer international. Volume 63:Issue 2(2014:Feb.)
• Page Start: 347
• Page End: 351
• Publication Date: 2013-05-13
• Subjects: Plastics -- Periodicals; Polymers -- Periodicals; Polymerization -- Periodicals; 547.7
• DOI: 10.1002/pi.4521
• Languages: English
• ISSNs: 0959-8103

Abstract

<abstract abstract-type="main"> <title>Abstract</title> <p> <bold>Rare earth solid super acids SO₄²⁻/TiO₂/Ln³⁺ have been successfully developed to synthesize vinyl end‐capped polydimethylsiloxane by ring opening polymerization of octamethylcyclotetrasiloxane (D4) end‐capped with 1, 1, 3, 3‐tetramethyl‐1, 3‐divinyldisiloxane. The features of ring opening polymerization reactions have been investigated in detail. The preferable conditions for the ring opening polymerization of D4 are as follows: [Nd³⁺] = 0.07 mol L⁻¹ and [SO₄²⁻] = 1.85 mol L⁻¹ in the immersing solution; the amount of SO₄²⁻/TiO₂/Nd³⁺ calcined at 500 °C was 5 wt% of the amount of D4; polymerization at 80 °C for 1 h. The average molecular weights of the products obtained using various rare earth catalysts were in order Nd &gt; La &gt; Sm &gt; Gd, which shows that the light rare earths were more favorable for higher molecular weight products than the heavy ones. According to the polymerization features, a cationic equilibrium reaction mechanism is proposed. © 2013 Society of Chemical Industry</bold> </p> </abstract>