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摘要
利用纤维素为载体合成了纤维素-ZnEt2-Y (CF3OO)3催化剂,以四氢呋喃为溶剂,研究了CO2与环氧乙烷和氧化环己烯三元共聚的反应条件。通过核磁共振氢谱证明所得共聚产物为三元无规则共聚物。同时考察了共聚反应影响因素,在最佳工艺条件下,催化效率高达2 806 g/(mol Zn);碳酸酯的含量可达90%以上;重均相对分子质量达17万左右;分子质量分布为3~4。通过热扫描曲线发现,三元共聚物的玻璃化转变温度随着EO摩尔比的增加而降低。热失重分析结果表明合成的三元共聚物具有高的热稳定性。另外,通过拉伸力学测试发现,随着环氧乙烷的加入,共聚物的断裂伸长率明显提高,脆性大大改善。
Abstract
Cellulose-ZnEt2-Y(CF3OO)3 catalyst is synthesized through using cellulose as carrier.The ternary copolymerization of CO2 with ethylene oxide (EO) and cyclohexene oxide (CHO) is achieved over the synthesized catalyst by using tetrahydrofuran as solvent.The obtained copolymer is confirmed to be a ternary random copolymer by means of 1H-NMR.Factors affecting the copolymerization reaction including carrier content,time,reaction solvent,temperature and pressure are investigated.Under the optimum conditions,the catalytic efficiency can reach as high as 2 806 g per mol of Zn;the content of carbonate may exceed 90%;the weight average molecular weight (Mw) is about 170 000;and the molecular weight distribution (Mw/Mn) is 3-4.It is found through DSC scan curve that the glass transition temperature (Tg) of the terpolymer decreases as EO content increases.TGA analysis indicates that the synthesized terpolymer has a high thermal stability.In addition,it is found by tensile mechanical tests that with the addition of EO,the elongation at break and the brittleness of the terpolymer both are significantly greatly improved.
关键词
纤维素
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环氧化合物
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脂肪族碳酸酯
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三元共聚
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负载催化剂
Key words
cellulose
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epoxide
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aliphatic carbonate
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ternary copolymerization
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supported catalyst
Author summay
马江涛(1991-),男,硕士研究生,研究方向为生物可降解材料,1270209771@qq.com
纤维素负载催化剂制备二氧化碳-环氧乙烷-氧化环己烯共聚物的研究[J].
, 2019, 39(10): 81-85,91 DOI:10.16606/j.cnki.issn0253-4320.2019.10.018