Environmentally Friendly Coatings : Past, Present Developments, and Future

Structural study of two grafted polyesters, which were different in mechanical properties, was investigated by DMA, TEM, and high‐resolution solid‐state 13C‐NMR. Using DMA and TEM, a separated phase larger than 100 nm was not found in the grafted polyesters. The main chain and the side chain seemed miscible. Analysis of T1ρHs and their distributions made the difference of microstructure in the grafted polyesters clear. P(EA‐AA)‐grafted polyester, which was very brittle, had a separated phase in the grafted polyester. The separated phase was estimated to be at a size of about 3 nm. On the other hand, P(St‐DEF‐MAnh)‐grafted polyester, which was very ductile, had a homogeneous microstructure. The difference in the microstructures of the grafted polyesters seemed to effect the mechanical properties of the grafted polyesters. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 392–402, 2000

Section: Introductionmentioning

confidence: 99%

Preparation of an acrylics-grafted polyester and its aqueous dispersion?Structural study of acrylics-grafted polyesters

Shimizu¹,

Nagara²,

Kaji³

et al. 2000

“…The reduction of volatile organic compounds and CO 2 has been acquiring intensive attention, and the reduction of the solvent emission from organic coatings such as paints and adhesives has been considered for about 20 years 1. High‐solids coatings, powder coatings, and water‐borne coatings have been developed to replace conventional solvent‐borne coatings; however, these coatings involved several problems,2 for example, high‐solids coatings still contain some solvents, powder coating systems need a breakthrough in the control of the film thickness, and even water‐borne coating systems have some problems.…”

Section: Introductionmentioning

confidence: 99%

Preparation of an acrylic-grafted polyester and its aqueous dispersion?Effect of the molecular structures of the grafted polyesters on viscosity and rheology of dispersion

Shimizu

Higashiura

Ohguchi

2000

An investigation was undertaken to develop a new class of water-borne polyesters that have various viscosity and various rheological profiles. We discussed the effect of the grafting condition on the molecular weights of the acrylic segments in the acrylic-grafted polyester. The molecular weights of the acrylic segments could be changed by an initiator concentration, a chain transfer agent concentration, and a monomer concentration. We discussed the viscosity and the rheology of the dispersions obtained from the above-grafted polyesters. The viscosity of the dispersion decreased as the molecular weights of the acrylic segments decreased. It was considered that the interaction between the particles of the dispersions decreased with a decrease in the thickness of the shell layer. The viscosity of the dispersions also decreased as the solubility of the acrylic segments in water decreased. It was considered that the interaction between the particle of dispersion decreased with the shrinkage of the shell layer. The rheological profile of dispersion was changed not by the molecular weights but the composition of the acrylic segments. The dispersions having various rheological profiles could be obtained by the control of the molecular weights or the composition of the acrylic segments in the grafted polyesters.

“…The reduction of volatile organic compounds and CO 2 has been acquiring intensive attention, and the reduction of the solvent emission from organic coatings such as paints and adhesives has been considered for about 20 years 1. High‐solids coatings, powder coatings, and water‐borne coatings have been developed to replace conventional solvent‐borne coatings; however, these coatings involved several problems, 2 for example, high‐solids coatings still contain some solvents, powder coating systems need a breakthrough in the control of the film thickness, and even water‐borne coating systems have some problems.…”

Section: Introductionmentioning

confidence: 99%

Preparation of an acrylics-grafted polyester and its aqueous dispersion

Shimizu

Higashiura

Ohguchi

1999

An investigation was undertaken to develop a new class of water-borne polyesters having excellent dispersibility without using emulsifiers. Grafting reactions of hydrophilic acrylics to polyesters and the relationships between reaction conditions and the dispersion diameters are discussed. Aqueous dispersions of particles having small diameters were obtained by use of an unsaturated polyester. Particle diameters were related to the grafting efficiency that could be enhanced by copolymerization of reactive monomers with the unsaturated bonds of polyesters. The relationships between particle diameters and the kind of acrylic monomers were described by the copolymerization reactivity ratio of the unsaturated polyester and acrylic monomers. Also, the influences of the solvency of the reaction medium and the influence of concentration of unsaturated bonds of the polyesters in the reaction medium were discussed to explain the low reactivity between the unsaturated bonds and acrylic monomers.