Polymer, Vol.55, No.16, 3543-3550, 2014
Facile synthesis of tunable alkali soluble latexes
Highly hydrophobic and highly hydrophilic (meth)acrylic monomers were copolymerized in heterophase system via a miniemulsion analogous polymerization technique. The versatility of the approach was demonstrated by the direct synthesis of hydrophobically modified alkali soluble emulsions (HASE) without the use of otherwise commonly required specialty monomers. It was demonstrated that copolymer composition drift during the course of the free radical heterophase polymerization the can be effectively regulated by the initial monomer ratios. This feature was employed to achieve (1) a more even distribution of acid functionalities throughout the growing polymer chains and the corresponding latex particles, (2) improved dissolution behavior upon deprotonation of the acid groups and (3) the possibility to tailor rheological properties at elevated pH values. Highly soluble HASE systems with surprisingly low contents of ionogenic groups and strong thickening effect were synthesized, which can provide beneficial characteristics in the coatings and adhesive sector. (C) 2014 Published by Elsevier Ltd.