Two-stage emulsion polymerization

All latex IPN s were synthesized by two-stage emulsion polymerization techniques (1 18) as follows To 300 ml of deionized deaerated stirre 3 waTer at 60°C were added 50 ml of a 10% (W/V) solution of sodium lauryl sulfate followed by 5 ml of a 5% (w/V) solution of potassium persulfate. The calculated quantity of comonomer was added at a rate of about 2 ml per minute. When the first monomer was fully added a minimum of one hour was allowed to elapse. Then a new portion of initiator was added but no new soap followed by the second charge of comonomers under similar reaction conditions. 

It can be shown theoretically that the relative amounts of the two monomers in a two-stage emulsion polymerization can affect the final particle structure [ 19], with core-shell morphology being favored thermodynamically, as the amount of second-stage polymer is increased. 

Wu and Zhao studied LIPN systems by a two stage emulsion polymerization technique [Wu and Zhao, 1995]. A latex seed (polymer 1) was synthesized first by a semi-continuous emulsion polymerization process, swollen by the second... 

Liu et al. also studied LIPN systems for damping control in coating applications [Liu et al, 1995]. A polystyrene (PS)/polyacrylate (PAcr) latex IPN was synthesized in a two-stage emulsion polymerization. Crosslinked PS was synthesized first as the seed polymer by a semi-continuous process,... 

Wu and Zhao studied LIPN systems by a two-stage emulsion polymerization technique (Wu and Zhao 1995). A latex seed (polymer 1) was synthesized first in a semicontinuous emulsion polymerization, swollen by the second-stage monomer or monomer mixture (forming polymer 2), and followed by polymerization to form IPN materials. Six kinds of monomers were used acrylonitrile (AN), vinyl acetate (VAc), n-butyl acrylate (liBA), methyl methacrylate (MMA), ethyl methacrylate (EMA), and ethyl acrylate (EA). The effect of composition, cross-linking level, feeding sequence of polymer 1 and polymer 2 on the IPN miscibility, and... 

The latex IPNs were synthesized by a two-stage emulsion polymerization technique. The first stage consisted of making a seed latex of crosslinked PVC polymer I and then introducing the monomer II mixture of butadiene and acrylonitrile and crosslinker followed by a second polymerization. The recipe for the seed latex was as follows ... 

In a broad study to evaluate the composite properties of hetero-geneous-latex-based materials, Dickie et synthesized a series of latex semi-IPNs. A two-staged emulsion polymerization procedure was employed that yielded relatively uniform populations of heterogeneous latex particles (HLP). The glassy component was prepared from methyl methacrylate, and the rubbery component used a mixture comprising 95 mol % butyl acrylate (BA) and 5 mol % 1,3-butylene dimethacrylate (BPMA). Heterogeneous latex particles in which the rubbery component was polymerized first were referred to by Dickie et al as HLPl particles for which the order of polymerization was reversed were referred to as HLP2. 

The two-stage emulsion polymerization technique was also used to produce polymer latexes bearing saccharide moieties on the particle surface for that a water-soluble monosaccharide monomer was used to functionalize styrene/butyl acrylate latexes [114]. 

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