Influence of spacer groups on grafting ability, curing ability, and film properties of water-based radiation curable latexes

Abstract

Film-forming polystyrene/poly(n-butyl acrylate-co-glycidyl methacrylate) [PS/P(BA-co-GMA)] core-shell latex particles were prepared via a two-stage emulsion polymerization procedure using a PS latex seed. A delayed addition of GMA was used to locate the functional epoxy groups near the surface of the particles. The surfacebound epoxy groups were used as grafting sites for unsaturated carboxyl functional monomers having the unsaturated groups and the carboxylic group separated by 1, 5, or 10 oxyethylene units. Grafting and curing characteristics and film properties after irradiation were investigated as a function of the number of oxyethylene units. A BA-GMA [P(BA-co-GMA)] copolymer was used as a model system for the core-shell latex particles for quantification of the grafting reactions. The grafting was demonstrated by FTIR and 1 H-NMR spectroscopy. The effects of crosslinking was studied by thermal mechanical analysis and dynamical mechanical analysis. Differential photocalorimetry was also used for evaluation of the curing ability. It was demonstrated that the reagent having five oxyethylene units in the spacer group was grafted onto the polymer backbones to a larger extent than the other two reagents, and a more thoroughly cured film was obtained upon irradiation.

Effect of introduction mode of hydroxyl functionality on morphology and film properties of cycloaliphatic diepoxide crosslinkable core‐shell latex

“…Without chemical bonding, albeit crosslinking, conventional latex coatings cannot give adequate chemical resistance and mechanical properties, and consequently several researchers have developed numerous thermosetting latex coatings. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] A number of crosslinkers have been used for latex coatings, including amino resins, isocyanates, carbodiimides, aziridines, oxazolines, and aromatic epoxides. However, some of these crosslinkers suffer with respect to environmental problems or have unsatisfactory coating properties.…”

Novel STY/nBA/GMA and STY/nBA/MAA Core−Shell Latex Blends: Film Formation, Particle Morphology, and Cross-Linking. 20. A Spectroscopic Study

“…Acrylate emulsion polymers containing epoxies or acid functional groups are widely used in many applications , because these reactive groups facilitate cross-linking reactions, thus enhancing physical and chemical integrity of coalesced latex films. As a result, impact strength, tensile, cohesion strength, and chemical resistance may be altered. , In essence, utilization of physical coalescence and chemical reactivity represent a combination of thermoplastic and thermosetting processes which involve water evaporation, latex particle packing, particle deformation, and coalescence with interparticle diffusion of polymer chains and cross-linking reactions .…”