纤维素苯甲酸酯接枝二乙二醇十六烷基醚的制备及性能

分别以1-烯丙基-3-甲基咪唑氯盐(Amim]Cl)和1-乙基-3-甲基咪唑醋酸盐(Emim]Ac)/N,N-二甲基乙酰胺(DMAc)为溶剂体系,以微晶纤维素(聚合度为220)和苯甲酰氯(BC)为原料制备纤维素苯甲酸酯(CB).探索了溶剂体系、反应温度和投料比对产物取代度、溶解性和熔融性能的影响.结果表明,以Amim]Cl为溶剂时,随着反应温度的升高(60~80℃)或体系中苯甲酰氯与葡萄糖单元环(AGU)投料量的增加(3∶1~9∶1),产物的溶解性和熔融性能均提高,取代度也随之升高(0.13~2.98);以Emim]Ac/DMAc为溶剂时,产物中苯甲酰基的接枝度较低,且共聚物中引入乙酰基不适合制备纤维素-g-苯甲酰氯.初步探讨了在Amim]Cl中合成纤维素苯甲酸酯接枝二乙二醇十六烷基醚(CB-g-E_2C_(16))固-固相变材料的性能,研究结果表明,CB-g-E_2C_(16)相变材料的相变温度为12.7~29.1℃,相变焓为12~24 J/g,在294℃仍能保持热稳定性,为该类纤维素基固-固相变材料的可熔融加工奠定了理论基础.

Preparation and Properties of Cellulose Benzoate and Preliminary Exploration About Cellulose Benzoate-g-polyoxyethylene(2) Hexadecyl Ether

Cellulose benzoate(CB) was prepared with microcrystalline cellulose(degree polymerization, DP=220) and benzoyl chloride(BC) as the raw materials.The ionic liquid 1-allyl-3-methyl imidazole chloride(Amim] Cl) and 1-ethyl-3-methyl imidazole acetate(Emim]Ac)/N,N-dimethyl acetamide were used as the solvent respectively.The effects on the degrees of substitution and solubility as well as melting property have been explored in different solvents, different reaction temperatures and different molar ratios.The results showed that the solubility and melting performance as well as the degrees of substitution(0.13_2.98) of the products were improved, with the increases of reaction temperatures(60_80 ℃) and the molar ratios of benzoyl chloride(3∶1_9∶1) in Amim]Cl, by 1H NMR, FTIR, DSC, TG and thermal stage microscope.The grafting degrees of substitution of benzoyl were low, and the acetyl was introduced in copolymer when Emim]Ac/DMAc was used as the solvent.It was demonstrated the dissolution system is not suitable for the reaction of cellulose grafting benzoyl chloride.Preliminary exploration has been carried out to synthesize BC-g-polyoxyethylene(2) hexadecyl ether solid-solid phase change material(CB-g-E2C16) in the Amim]Cl.The results showed that the phase transition temperatures and enthalpy of phase change of CB-g-E2C16 were 12.7_29.1 ℃and 12_24 J/g, respectively.The thermostability was 294 ℃.It laid a certain foundation for subsequent detailed exploration about the performances of the cellulose based phase change materials.