Polyethylene glycol monomer is an important monomer for the synthesis of functional polymer materials. The direct esterification method is one of the main methods for synthesizing such monomers

but the product prepared by this method has a low double bond retention rate. To solve this problem

in this study

Polyethylene glycol monomethyl ether-200 acrylate (MPEGA-200) with high yield and high double bond retention was synthesized by direct esterification of methoxy polyethylene glycol (MPEG-200) with acrylic acid (AA)

and by introducing color-changing silica gel into the reaction system based on the presence of a water-carrying agent to enhance the water removal efficiency. FT-IR and 1H NMR were used to characterize MPEGA-200

and the biocompatibility of MPEGA-200 was evaluated by catalase activity analysis. The optimal conditions for synthesizing MPEGA-200 were determined by orthogonal experiments. The results shown that the optimal conditions are:

n

(MPEG-200)∶

n

(AA)=1∶2

the additions of inhibitor and catalyst were 2% (based on the total acid and alcohol mass)

18% of petroleum ether and 12% of color-changing silica gel

the reaction time was 6h

and the esterification temperature was 120℃. Under the conditions

95.47% of esterification rate

95.45% of double bond retention and 87.68% of yield can be reached. In addition

the influences of various factors on esterification were studied by the single factor method.