窄分布低分子质量端羟基聚四氢呋喃的合成与研究

Synthesis and characterization of hydroxyl-terminated PTHF of low molecular weight with narrow distribution

以三氟化硼乙醚配合物(BF3.OEt2)为催化剂,环氧丙烷(PO)为起始剂,二氯甲烷(CH2Cl2)作溶剂,通过四氢呋喃的阳离子开环聚合合成了窄分子质量分布(Mw/Mn<1.3)的端羟基聚四氢呋喃(PTHF)。研究了三氟化硼乙醚配合物用量、溶剂用量、起始剂用量、反应时间对PTHF分子质量(Mn)及其分布(Mw/Mn)的影响。实验研究表明:减少三氟化硼乙醚配合物或二氯甲烷用量可使Mn增大,反应时间超过40min后,反应时间对Mn及Mw/Mn影响不大;在冰水浴中,有环氧丙烷存在时,可实现分子质量(Mn=1 000～4 000)及分子质量分布(Mw/Mn=1.16～1.36)PTHF的制备。

Hydroxy terminated polytetrahydrofuran （PTHF） with narrow molecular weight distribution （Mw/Mn 〈 1.3） is synthesized by cationic ring-opening polymerization of tetrahydrofuran using boron trifluoride ethylether complex （ BF3OEt2 ） as a catalyst,propylene oxide（PO） as a initiator and dichloromethane（ CH2Cl2 ） as a solvent. The influences of the amount of boron trifluoride ethylether complex, dichloromethane and propylene oxide, and polymerization time on the molecular mass（M.） and Mw/M. of PTHF are studied. The results show that the higher M. can be obtained by reducing the amount of boron trifluoride ethylether complex or dichloromethane. The polymerization time exerts less effect over 40 min. In the ice water bath, the molecular weight of PTHF （ Mn= 1 000 - 4 000 ） with molecular weight distribution （Mw/Mn= 1.04 - 1.27） can be obtained when propylene oxide is present in the system.