Poly(vinyl acetate‐co‐dibutyl maleate) latex films in the presence of grafted and post‐added poly(vinyl alcohol)

Abstract

We describe the synthesis and characterization of a series of poly(vinyl acetate‐co‐dibutyl maleate) [P(VAc‐DBM)] latex particles (monomer molar ratio 10.6:1). One set of samples [high‐M and M250k SDS‐P(VAc‐DBM), gel content 50% and 0%] was prepared in the presence of an anionic surfactant sodium dodecyl sulfate. The other two sets of samples [high‐M and M250k PVOH–P(VAc‐DBM)] were prepared in the presence of poly(vinyl alcohol) (PVOH). These polymers differ in gel content (50 and 0%) and the extent of PVOH grafting (30 and 15%). Polymer diffusion across cell boundaries in the latex films was monitored by fluorescence resonant energy transfer (ET) experiments. First, we examined M250k samples in the presence of grafted and post‐added PVOH. The presence of post‐added PVOH (5%) causes a small but detectable retardation on the rate of polymer diffusion, whereas the presence of grafted PVOH (degree of grafting: 15%) significantly promotes the polymer diffusion rate. For the high‐M P(VAc‐DBM), the presence of post‐added PVOH also retards the polymer diffusion. Strikingly, the presence of grafted PVOH (degree of grafting: 30%) in the high‐M PVOH‐P(VAc‐DBM) promotes the polymer diffusion to such an extent that the diffusion was complete in the freshly prepared films. Our data also suggest that under our experimental conditions, the rate of P(VAc‐DBM) diffusion increases with an increase of the degree of PVOH grafting. To confirm these results, we carried out fluorescence microscopy experiments to monitor the fate of PVOH in these latex films and found that in newly formed PVOH–P(VAc‐DBM) films, the PVOH was either uniformly distributed in the P(VAc‐DBM) matrix or the domains were too small to be resolved (i.e., < 0.5 μm). © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5005–5020, 2004

Isolation of the effect of the hairy layer length on the mechanical properties of waterborne coatings

“…As polymer diffused across particles boundaries, donor and acceptor dyes get into proximity leading to an increment in the extent of energy transfer and therefore to a faster decrease in the fluorescence decay profile [26][27][28][29]. In our experiments, each fluorescence decay profile was standardized to unit intensity and t = 0 and fitted to the following equation [30][31][32][33][34]:…”

“…Thus, ˚E T can be related to the fraction of molecular mixing in a system of labelled particles and it is defined as shown in Eq. (2) [31,33,[36][37][38]:…”

“…Another useful parameter is the extent of mixing, f m (t), expressed in terms of the increase in energy transfer, normalized by the maximum change associated with complete mixing [31,33,[36][37][38]:…”

Síntesse de novos estabilizantes poliméricos do tipo poli(álcool vinilico-co-neo decanoato de vinila) para utilização na copolimerização em miniemulsão do acetato de vinila (VAc) com o neo-nonanoato de vinila (VEOVA-9)

“…Além disso, a utilização do PVA para produção de adesivos confere ao produto final características adesivas quando aplicado sobre diferentes substratos, melhora as propriedades mecânicas dos filmes, confere características reológicas (tixotropia), melhora as propriedades de aplicação e compatibilidade com diferentes substratos, além de ser biodegradável e biocompatível (RAGHAVAN, 1995;NAKAMAE et al, 1999;KIM et al, 2004a;WU et al, 2004).…”

“…PENG, 2007), mantas (ZANG et al, 2005), filmes para embalagens (BLACKWELL, 1986;MARTEN, 1988), revestimento de papéis (FINCH, 1992) e como estabilizantes para reações de polimerização em suspensão (COUTINHO et al, 2000, RAMIREZ et al, 2006, em emulsão (FARMER, 1992;FINCH, 1992;NAKAMAE et al, 1999;PARK et al, 2001;SARAC et al, 2002;WU et al, 2004;CARRÀ et al, 2005) e em miniemulsão (KIM, 2003, Revisão Bibliográfica KIM et al, 2003KIM et al 2004a,b;BOHÓRQUEZ e ASUA, 2008a,b), principalmente quando o látex obtido é utilizado na fabricação de adesivos para diversas aplicações (WARSON, 1981(WARSON, , 2001). Atualmente, devido a sua biocompatibilidade e biodegradabilidade o PVA tem sido muito utilizado na fabricação de nanofibras (GUERRINI et al, 2006(GUERRINI et al, , 2009, hidro-géis (HASSAN;PEPPAS, 2000;MANSUR et al, 2007), lentes de contato, componentes artificiais do organismo humano e sistemas de liberação de fármacos (LI et al, 1998;HASSAN;PEPPAS, 2000;NAGARA et al, 2001;ZENG et al, 2004).…”