Sizing agents acrylics

Acrylic acid (ca. 1855) (propenoic acid, vinylformic acid) n. CH2=CHCOOH. A colorless, unsaturated acid, that polymerizes readily. The homopolymer is used as a thickener and textile-sizing agent and, cross-linked, as a cation-exchange resin. Acrylic-acid esters are widely used as monomers for acrylic resins. Mol wt., 72.06 mp, 14°C bp, 141.0°C Sp gr, 1.422. 

Poly(acrylic acid) A polymer of acrylic acid used as a sizing agent in the manufacture of nylon and other synthetic textiles See image). 

Polymeric Sizing Agents (PSA) are mainly based on styrene-acrylates, polyurethanes or styrene-maleic acid anhydride. They are either water-based dispersions or aqueous solutions. These products were developed around 1960. Since that time an increasing number of size-presses for strength improvement with starch have been installed. 

Uses Detergent emulsifier welling agent dispersant imparls small particle size in acrylate emulsion polymers emulsifier for floor polish emulsions Properties Liq. 35% cone. 

For surface sizing, mostly polymeric sizing agents are used. The most important product classes are acrylic copolymer dispersions stabilized by protective colloids. The particles of the sizing agent consist of a hydrophobic polymer core and a hydrophilic shell formed out of the protective colloid (Fig. 4-5). 

When the polymer was prepared by the suspension polymerization technique, the product was crosslinked beads of unusually uniform size (see Fig. 16 for SEM picture of the beads) with hydrophobic surface characteristics. This shows that cardanyl acrylate/methacry-late can be used as comonomers-cum-cross-linking agents in vinyl polymerizations. This further gives rise to more opportunities to prepare polymer supports for synthesis particularly for experiments in solid-state peptide synthesis. Polymer supports based on activated acrylates have recently been reported to be useful in supported organic reactions, metal ion separation, etc. [198,199]. Copolymers are expected to give better performance and, hence, coplymers of CA and CM A with methyl methacrylate (MMA), styrene (St), and acrylonitrile (AN) were prepared and characterized [196,197]. 

The small amount of acrylic acid is required to ensure freeze/thaw stability of the latex at a pH of 7 or higher and contributes to its mechanical stability. The anionic emulsifier (Fenopon SF 78) regulates the particle size and contributes to the stability of the system during latex preparation. The nonionic emulsifier (Tergitol NP 40) is required to obtain sufficient electrolyte stability and contributes to the mechanical and the freeze/thaw stability of the latex. Borax is used as a neutralizing agent. 

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