Preparation, acidolysis kinetics and scale inhibition performance of low molecular weight poly(maleic anhydride-alt-vinyl acetate) based on self-stabilized precipitation polymerization

Poly(maleic anhydride-alt-vinyl acetate) (PMV) is used as a fine chemical in the field of biomedical. However, the techniques of PMV preparation have shortcomings like limited yield (Y-p), complex post-treatment and toxic solvents. Herein self-stabilized precipitation (2SP) technique which possessed advantages of simple operation and post-processing, non-toxic solvent, and surface-cleaned product is adopted to synthesize low number-average molecular weight (M-n) PMV by tune-up of reaction parameters. PMV with M-n of 2800-39,200 g/mol are successfully achieved. Furthermore, acidolysis kinetics of PMV is investigated centering on effects of M-n, acidolysis temperature, and initial concentration. All samples can undergo completely ring-opening and the equilibrium pH of acidolyzed PMV is related to initial concentration irrelevant to M-n and temperature. Carboxylic degree (CD) varying rate and time of reaching equilibrium pH and 100% CD are impacted by M-n and temperature irrelevant to initial concentration. Finally, scale inhibition effectiveness of PMV with 2800 g/mol can be up to 53.69%, larger than that of commercial citric acid by about three times. This contribution supplies an easily operational and eco-friendly process to obtain low molecular weight PMV which can be the scale inhibitor for industry and daily life, providing the quantization basis for hydrophilic functionalization of PMV.