Determination of the Relative Molecular Mass and Its Distribution of PAMMO by GPC

A gel permeation chromatography(GPC) test method was established with polyethylene glycoKPEG) as standard sample.The relative molecular mass and its distribution of 3-azidomethyl-3-methyloxetane homopolymer(PAMMO) were determined.The effect of column temperature and sample concentration on the test results was studied.The best experimental conditions were determined.The relative molecular mass of PAMMO samples from different batchs were tested.A comparison of the values obtained by GPC test method and the ones obtained by a combination method of GPC and Multi-angle Laser Light Scatterometer(GPC/MALLS),vapour phase osmometry(VPO) and titration method of hydroxyl end-group was performed.Results show that the repeatability of GPC test method is good.The relative standard deviations(RSD) of number-average molecular mass(Mn),weight average molecular mass(Mw) and polydispersity index(PD) are all less than 5%,revealing that the traditional GPC test method can be used to determine the relative molecular mass and its distribution of PAMMO and to guide the improvement of PAMMO synthesis process and choice of post-processing method.