Particle morphology and NMR structure of polymethylmethacrylate/polystyrene emulsifier‐free core–shell cationic latices in the presence of DBMEA

Abstract

ABSTRACT:In the absence of emulsifier, we prepared stable emulsifier-free polymethylmethacrylate/polystyrene (PMMA/PSt) copolymer latex by batch method with comonomer N, N-dimethyl, N-butyl, N-methacryloloxylethyl ammonium bromide (DBMEA) by using A1BN as initiator. The size distribution of the latex particles was very narrow and the copolymer particles were spherical and very uniform. Under the same recipe and polymerization conditions, PMMA/PSt and PSt/PMMA composite polymer particle latices were prepared by a semicontinuous emulsifier-free seeded emulsion polymerization method. The sizes and size distributions of composite latex particles were determined both by quasi-elastic light scattering and transmission electron microscopy (TEM). The effects of feeding manner and staining agents on the morphologies of the composite particles were studied. The results were as follows: the latex particles were dyed with pH 2.0 phosphotungestic acid solution and with uranyl acetate solution, respectively, revealing that the morphologies of the composite latex particles were obviously core-shell structures. The core-shell polymer structure of PMMA/PSt was also studied by 1 H, 13 C, 2D NMR, and distortionless enhancement by polarization transfer, or DEPT, spectroscopy. Results showed that PMMA/PSt polymers are composed of PSt homopolymer, PMMA homopolymer, and PMMA-g-PSt graft copolymers; results by NMR are consistent with TEM results.

Silane-Bridged Electroless Ni-Plating on Submicron Polymer Spheres

“…Better control over the size distribution of the submicron polymer cores calls for the need of alternative strategy. 2,5 Zhang et al 10 demonstrated that the emulsifier-free emulsion polymerization is a process that is capable of obtaining submicron scaled polymer spheres with narrow distribution of particle size. They also pointed out that the merit of such process is the spherical geometry of the product.…”

“…They also pointed out that the merit of such process is the spherical geometry of the product. 10 The method of metallic coating is another technological issue in fabricating such material. Metallic coating can be achieved by direct surface reactions of the specific functional groups on the polymer core with vaporized metal in physical vapor deposition (PVD).…”