Copolymers with varying molar ratios were created by initiating hydroxyethyl acrylate and maleic anhydride monomers with ammonium persulfate. A capillary dilatometer was used to measure the conversion of copolymerization. The copolymer’s composition curve was determined using acid-base titration

and the reactivity ratios of hydroxyethyl acrylate to maleic anhydride were determined using the YBR method. According to the calculation results

r

1(HEA)

and

r

2(MA)

were 2.3188 and 0.0272

respectively

indicating that hydroxyethyl acrylate should be slowly added to maleic anhydride in order to obtain a uniform copolymer. Finally

it can be obtained by potentiometric titration

the p

K

a1

and p

K

a2

values of copolymer with the molar feed ratio of 7∶3 are 4.33 and 7.59

respectively.