Vitrimers of polyolefin elastomer with physically cross-linked network

编号 020031901

推送时间 20211129

研究领域 林产化工 

年份 2021 

类型 期刊 

语种 英语

标题 Vitrimers of polyolefin elastomer with physically cross-linked network

来源期刊 Journal of Polymer Research

期 第319期

发表时间 20210514

关键词 Poly(ethylene-α-octene);  Physically cross-linking;  Dynamic boronic ester bonds;  Properties; 

摘要 Dynamics of exchange within vitrimer networks are influenced by mobility of the chemical species involved in the exchange reaction, then it can be affected by the crystalline phase when boronic ester bond is introduced into the thermoplastic elastomers with crystalline phase as physical cross-links. In this work, the dynamic dioxaborolane cross-links were introduced into commercial poly(ethylene-α-octene) (POE) with crystalline phases as physical cross-links to prepare POE vitrimers. The results of stress relaxation show that relaxation time (τ) follows an Arrhenius law with the temperature at the melting range for not only POE vitrimers and thermally treated POE vitrimers with dynamic cross-links, but also neat POE with purely physical cross-links. The liquid-to-solid transition temperature can raise to 35.3?°C for POE vitrimers from -42.9?°C of the thermally treated one, due to the constrained mobility by residual crystalline phases. The resulted POE vitrimers maintain a stress at break of higher than 27.5?MPa and an elongation at break of higher than 800% at room temperature. With the temperature increasing, the crystal melting induced weakening of the physical cross-linking in POE decreases the strength, but the storage modulus and the stress at 300% and 500% elongation of POE vitrimers are improved. The properties of POE vitrimers can almost keep unchanged after recycling or healing. All these results show that the introduction of reversible boronic ester bonds is a promising strategy to improve the performances and recyclability of physically cross-linked POE materials.

服务人员 尚玮姣

服务院士 宋湛谦

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