Hydrogen Bonding Between Linear Aliphatic Polyester/Boltorn Hyperbranched Polyester Blends

The interaction between polymer molecules is one of the basic research in polymer science.As an important type of intermolecular interaction,hydrogen bonding has been widely concerned by the academic community.In this paper,the solution blending method was used to prepare polymer blends.And two series of linear polyesters were separately blended with Boltorn HBP by using THF as cosolvent and the solution was casted and dried to prepare the blends.Fourier Transform infrared spectroscopy was used to study the effect of different conditions on the hydrogen bond formation between the two components of the blend.Firstly,two series of linear polyesters were synthesized by melt polycondensation:(1)four different diols were separately used with dodecanedioic acid for polycondensation;(2)four different dibasic acids were separately used with ethylene glycol for polycondensation.Secondly,the fourth generation HBP was synthesized by stepwise decreased-temperature polycondensation method with PEL as the central core and DMPA as the branching unit.Thirdly,two series of linear polyesters were separately blended with HBP in solution to study the hydrogen bonding between the two components of the blend.The results showed:1?The HBP contents,solution standing time,solution concentration,heat treatment temperature and linear polyester's flexibility all had important effects on the formation and quantity of hydrogen bond between the two components of the blend.The more HBP contents,the more the number of terminal hydroxyl groups increased rapidly,and the more hydrogen bonds formed with the ester carbonyl groups in the linear polyesters;2?When the blends were prepared by solution blending,the longer time the solution stand,the more hydrogen bonds were formed,especially in the case of high content of HBP,i.e.the higher the hydrogen bond content;3?In high concentration solution,the content of hydrogen bond formed between the two components of the blend was higher.But with the increase of the flexibility of linear polyester,the effect of the flexibility of linear polyester on the content of hydrogen bond was higher than that of concentration on the content of hydrogen bond;4?When the blend film was heat treated near the melting point of the linear polyester or near the glass transition temperature of the HBP,the hydrogen bond content on the surface of the blend film reached a high value or maximum value,which indicated that the heat treatment temperature had an important effect on the hydrogen bond content.