Latex interpenetrating polymer networks based on polyacrylates and polystyrene. II. Effect of methacrylic acid concentration in the seed

✍ Scribed by P. Nagarajan; C. K. Mital; M. K. Trivedi

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 440 KB
• Volume: 59
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19960110)59:2<197::aid-app2>3.0.co;2-s

✦ Synopsis

Latex interpenetrating polymer networks (LIPNs) were prepared by swelling the polyacrylate seed (comprised of methyl methacrylate and n-butyl acrylate in the ratio of 45 : 55 by weight), having different amounts of methacrylic acid (MAA) ranging from 0 to 6 w t %, with styrene monomer, whose polymer constituted the other network, to study the effect of MAA content in the seed on the final latex properties. The swelling and polymerization of styrene monomer and the crosslinker were done at two different pH values (viz., 3.3 and 8.5) for all the LIPNs. The LIPNs with the minimum MAA amount of 1.2 in the seed yielded translucent film at low pH and transparent film at high pH, upon drying at ambient temperatures. The LIPNs showed multiphase morphology with seeds having minima of 0.2 and 0.5% MAA when processed at high and low pH, respectively. Tensile strength and hardness (Shore-D) also increased from 4 to 13.2 MPa and 35 to 52, respectively, with an increase in the acid concentration from 0 to 6% as a result of increased mixing of the two polymers.