Synthesis of grafted bromoisobutyryl esterified starch using electron transfer atom transfer radical polymerization...

Nowadays, few investigations on the process parameters of grafted starch synthesized using electron transfer atom transfer radical polymerization (ARGET ATRP) and its applications in warp sizing and paper-making are presented. Therefore, this study aimed to survey the appropriate process parameters of bromoisobutyryl esterified starch-g-poly(acrylic acid) (BBES-g-PAA) synthesized by the ARGET ATRP, and also aimed to provide a new biobased BBES-g-PAA adhesive. The appropriate synthesis process parameters were 1.2, 0.32, and 0.6 in the molar ratios of vitamin C, CuBr₂, and pentamethyldivinyltriamine to BBES, respectively, at 40 °C for 5 h. The BBES-g-PAA samples with a grafting ratio range of 4.63-14.14 % exhibited bonding forces of 57.8-64.6 N to wool fibers [55.5 N (BBES) and 53.8 N (ATS)], and their films showed breaking elongations of 3.29-3.80 % [2.74 % (BBES) and 2.49 % (ATS)] and tensile strengths of 29.1-25.4 MPa [30.4 MPa (BBES) and 34.7 MPa (ATS)]. Compared with BBES, significantly increased bonding forces and film elongations, and decreased film strengths for the BBES-g-PAA samples with grafting ratios ≥10.54 % were displayed (p < 0.05). The time (100-42 s) taken for the BBES-g-PAA films was significantly shorter than that of ATS (246 s) and BBES (196 s) films (p < 0.05), corresponding to better desizability.