环氧丁羟型聚氨酯弹性体的制备与性能  

Preparation and Properties of Epoxided Hydroxyl-terminated Polybutadiene Based Polyurethane Elastomers

作　　者：曹哲[1] 介素云[1] 李伯耿[1] 

机构地区：[1]化学工程联合国家重点实验室浙江大学化学工程与生物工程学院,杭州310027

出　　处：《高分子学报》2017年第8期1350-1357,共8页Acta Polymerica Sinica

基　　金：浙江省自然科学基金(基金号LY16B040001);国家自然科学基金(基金号21536011)资助项目

摘　　要：以间氯过氧苯甲酸(mCPBA)为氧化剂对降解法制备的端羟基聚丁二烯(DHTPB)中的部分双键进行环氧化改性,通过控制mCPBA和双键的比例制得具有不同环氧率的环氧化端羟基聚丁二烯(EHTPB),经1H-NMR分析测试表明EHTPB的环氧率分别为5%、10%和15%,与设计值基本一致.进一步以EHTPB为多元醇、4,4'-二苯基甲烷二异氰酸酯(MDI)为异氰酸酯、1,4-丁二醇为扩链剂制备了环氧丁羟型聚氨酯弹性体(EPU),并对其性能进行了测试,研究结果表明:丁羟胶的环氧化改性对聚氨酯弹性体的力学性有着一定的提升作用,其杨氏模量和拉伸强度随环氧率的上升而提高,而断裂伸长率则随环氧率的上升有所下降;环氧丁羟型聚氨酯弹性具有优异的弹性恢复能力;环氧化改性后,聚氨酯弹性体的热稳定性有一定程度的提高;聚氨酯弹性体的玻璃化转变温度随环氧率的上升而升高.The C=C double bonds in the main chain of hydroxyl-terminated polybutadiene（DHTPB）, obtained by the degradation of polybutadiene rubber, were partially epoxided using m-chloroperoxybenzoic acid（m CPBA） as epoxidation reagent. A series of epoxided HTPBs（EHTPB） with different epoxy contents（5%, 10% and 15%） were prepared by tuning the molar ratio of m CPBA to C=C double bonds. The structures of EHTPBs were characterized by Fourier transform-infrared（FTIR）, nuclear magnetic resonance（1H-NMR） spectroscopy and gel permeation chromatography（GPC）. The epoxy percent in EHTPBs from 1H-NMR spectra was in accordance with the design. In addition, a series of EHTPB-based polyurethane elastomers（EPU） were prepared by the reaction between EHTPB and 4,4＇-diphenylmethane diisocyanate with 1,4-butanediol as a chain extender. Mechanical and thermal properties of the EPU samples were characterized by tensile test, differential scanning calorimetry（DSC） and thermal gravity analysis（TGA）. With increased epoxy percent in EHTPB, the Young＇s modulus and the tensile strength of the EPU samples increased, whereas the elongation at break decreased. The sample EPU10 prepared with 10% of epoxy had the best mechanical properties with 8.82 MPa as Young＇s modulus, 7.83 MPa as tensile strength, and（485 ± 23）% as elongation at break. The elasticity recovery of the EPU sample was slightly better than HTPB-based PU（EPU0）. The results with TGA test showed that the thermal degradation of EPU, similar to EPU0, was divided into three stages. However, the EPU samples had better thermal stability with the initial degradation temperature at 210℃, about 30 ℃ higher than that of EPU0. The DSC results showed that the glass transition temperature（Tg） of EPU gradually increased as epoxy percent was increased, though still lower than that of HTPB（FHTPB） based PUs prepared by free-radical polymerization.

关 键 词：聚氨酯弹性体 丁羟胶 环氧化 力学性能 热性能 

分 类 号：TQ334[化学工程—橡胶工业]