The mechanism of emulsion polymerization. II. Branching in polymers prepared by emulsion polymerization techniques

Preparation and structure of poly(vinyl alcohol)–poly(vinyl acetate) composite porous membrane

“…The absorbances at 400 nm wavelength, which were adopted for convenience as a measure of the solubility, showed the minimum at 5.0/1.0 ratio (by vol) of methanol/water in every case. The minimum turbidities in the solubility measurement of the PVAc lattices formed by method [11] using APS and by method [I] using HPO-TA were higher than others. Mixture R a t i o of S o l v e n t …”

“…The transmittance of the PVAc latex films, which were formed above the minimum film-forming temperature, varied from a high value for methods [11] and [111] using HPO-TA to a low value for method [11] using APS and method [I] using HPO-TA.…”

“…In method [11], the process was similar to the method [I], except that initiator was stepwise added as described (Fig. 1).…”

“…The polymerization methods [I], [11], and [111] indicate the dropwise addition of VAc and initiator, the dropwise addition of VAc and the stepwise addition of initiator, and the batch method in which all ingredients of the batch (water, VAc, PVA, and initiator) were put into the reaction vessel before starting polymerization, respectively. Polymerizations were performed in a 1-L fivenecked separable flask equipped with a thermometer, a reflux cooler, a VAc dropping funnel, an initiator dropping funnel, and a stirrer.…”

“…High viscosity PVAc latex was very convenient for casting and forming the latex film. The PVAc particle size, which was evaluated from the dispersion quantity (Table I), was in the order of [I] > [11] > [111] in the method using HPO-TA.…”