The Polybutylene succinate-co-adipate (PBSA) emulsion for biodegradable adhesives was investigated with respect to wetting characteristic and film formation and the following results were obtained.1.Biodegradation of PBSA emulsion and its derived products proceeded as fast as that of microcrystalline cellulose.2.PBSA emulsion was easily susceptible to bacteria and mildew than conventional polymer emulsion and more loading of biocide was necessary.3.To understand wetting characteristic of PBSA, surface free energyr γs, its dispersion component γsd and its polar component γsp were calculated from contact angles of water and methylene iodide and were then compared to those of PVAc. The results were as follows: γs=51.8, γsd=33.2, γsp=18.6 for PBSA and γs=51.7, γsd=35.2, γsp=16.5 for PVAc, respectively, in mN/m. Consequently PBSA emulsion is expected to have similar potentiality as adhesives as PVAc emulsion from the view point of surface chemistry.4.Emulsions of PBSA and PVAc gave respectively rather fragile films by simple heating. However simultaneous heating and pressing turned the PBSA emulsion film tough by stimulating particles to coalesce, but the PVAc emulsion film more fragile by destroying PVA-layers firmly sticking to the particles.5.Therefore it is expected that PBSA emulsion has substantial potentiality for newly born biodegradable adhesives. Textile fabric adhesion, production of pigment-coated paper and heat sealing of paper were demonstrated as examples better than conventional polymer emulsion.

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Pressure sensitive adhesives are utilized widely in the industry. The impact energy absorption as well as the tackability is notable properties of the pressure sensitive adhesives. The purpose of this study is to investigate the effect of soft adhesive layer on the impact energy absorption. Four types of plastic plates were used in this study; polycarbonate, polyamide, polyacetal and PMMA. Impact tests were carried out on the mono-layered and multi-layered polymer/adhesive laminates. Effect of soft adhesive layer on the energy absorption depends on the material type. For the multi-layered laminates, every material had the increase in the energy absorption by the adhesion with soft layer. In particular soft layer affected largely on the increase in the absorption for the polyacetal and polyamide 66. As a result of impact rate dependency analysis, the absorption energy increased with decreasing impact velocity for all the samples that indicated the improvement in the energy absorption. The increase in the energy absorption could be explained by the decrease in the strain rate.

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