ABSTRACT
Extremely high concentrated aqueous solutions of acrylic acid [AA] were polymerized in presence of British Gum [BG] using ammonium persulfate initiator. The reaction was carried out at different ammonium persulfate concentration [9.5x10[-3]- 38.1x10[-3] mol/l], temperature [65-95°C], degree of neutralization of AA [Na-form] [0-20%], and LR [0.6-3.6 l/k]. At optimal reaction conditions, the reaction was extended to include other pyrodextrins [PDs], namely Dexy 84 [D84] and Dexy 85 [D85] to prepare three polyacrylic acid [PAA/PD] adducts, namely PAA/BG, PAA/D84 and PAA/D85 adducts. These adducts were found to compose mainly of PAA-g- PDs and ungrafted PD with small amounts of PAA homopolymer and a very slight amount of AA. Rheological properties of aqueous solutions [8% w/v] of these adducts at 75 +/- 0.1°C showed that all were characterized by a non- Newtonian thixotropic flow. 15% and 100% neutralized [Na-form] adducts were utilized in sizing of gauzy cotton fabric. It was found that PAA/BG [100% neutralization] is the best amongst adduct studied in improving the mechanical properties of sized samples. Complete removal of size was observed upon using all adducts at a 100% degree of neutralization