Thermoplastic Triblock Copolymers Based on Oxetane Derivatives and Their Application in Energ Propellant Binders and Phosphorus-Containing Monomers and Polymers for Flame Retardants

• Main Authors: Liu, Ying Ling, 劉英麟
• Other Authors: Hsiue, Ging Ho
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/57634603671863612612

博士 === 國立清華大學 === 化學工程研究所 === 84 === The goal of this endeaver in the first part is to synthesize oxetane derivatives and tetrahydrofuran based triblock copolymers as rocket propellant binders. A two-end living cationic polymerization system is first established by using triflic anhydride as an initiator. The active species of the propagating reaction in this polymerization system are determined to be macro-oxonium ions and triflic macro-esters. The two end living polymerization system is utilized to synthesize A-B-A type triblock copolymers. The A-B-A triblock copolymers possess hard segments A of poly(oxetanes) and soft segment B of poly(tetrahydrufuran). Copolymers with various molecular weights, narrow polydispersities, low glass tran- sition temperatures, good mechanical property, and thermo- plastic elastomer characteristics, and energetic properties are obtained. The energetic thermoplastic elastomers are useful in serving as propellant binders. In addition, a novel addition reaction on oxetane rings are also developed using triflic acid as an intermediate. The addition reaction is utilized in polymer reaction to synthesize functional side-chain polymers. The second part of this endeaver aims at developing phosphorus- containing polymers for reactive polymer flame retardants. Polymers with various controlled phosphorus contents are obtained via changing the feed ratios of the reactants in the polymer phosphorylation. Moreover, phosphorus-containing epoxy resins are prepared. High char yields and limiting oxygen index (LOI) values are founded for the phosphory- lated epoxy resins. This confirmed the high flame retardancy of these phosphorus- containing epoxy resins. Moreover, the flame retardant efficiency could be further leveled up by intro- ducing silicon into the resins. As a result, the P/Si synergistic effect on flame retardancy is confirmed.