سال انتشار: ۱۳۸۳

محل انتشار: نهمین کنگره ملی مهندسی شیمی ایران

تعداد صفحات: ۱۰

نویسنده(ها):

علیرضا مهدویان – Polymer Science Department, Iran Polymer & Petrochemical Institute, Tehran, Iran
مهدی عبداللهی – Polymer Science Department, Iran Polymer & Petrochemical Institute, Tehran, Iran
فرود عباسی سورکی – Polymer Science Department, Iran Polymer & Petrochemical Institute,Tehran, Iran

چکیده:

Carboxylated styrene- butadiene latexes with 30% solid content were prepared by emulsion copolymerization technique with initial charge and shot- addition methods. The distribution of carboxylic groups in different locations of latex system i.e. interior and surface of particles and aqueous phase during polymerization reaction was studied by conductometric back titration method (Hen method). The obtained results from
shot process show that addition of acrylic acid with some water in interval III of emulsion polymerization will decrease the amount of surface bound carboxylic acids relative to initial charge method. So the process of shot- addition was modified by addition of styrene, emulsifier and initiator accompanied with acrylic acid and water in conversions above 80% in the second stage. The analysis of the obtained latex shows
that the amount of surface bound acid was raised from 58% for initial charge method to 72% for this modified technique.