The Effect of Different Soft Core/Hard Shell Ratios on the Coating Performance of Acrylic Copolymer Latexes.

Catalina Cheaburu-Yilmaz,Raluca Darie-Nita,Onur Yilmaz

doi:10.3390/polym13203521

Abstract

Core–shell acrylic copolymer latexes containing bio resourced itaconic acid with different compositions in respect with the core and shell segments were synthesized, characterized, and applied as coating materials for leather. The purpose of the study was to evidence the high coating performance of the latexes when the ratio of the core/shell differed from 90/10 to 50/50 wt %. The copolymers were prepared via emulsion copolymerization technique and the products were isolated and characterized by means of structure identity, thermal behavior (DSC and DMTA), coating performance. The particle size of the latexes varied from 83 to 173 nm with the variation of the ratio of core/shell segments. The influence of the composition of soft part and hard part was highlighted in the thermal and coating properties. The optimal composition giving the best coating performance could be determined as DS 60/40. Further increase of the hard segment content, resulted in decreased emulsion stability and the coating performance on the leathers. The use of itaconic acid seemed to increase the emulsion stability as well the adhesion of the latexes to the substrate.

Highlights

Leather finishing is regarded as a stepwise process occurring in the final stage of leather manufacturing, and it is considered very important, as the final properties of leather goods such as appearance, coverage of surface defects and scratches, glossiness, feel, touch, color uniformity, fashionable effects, and patterns as well as mechanical and weathering resistance properties are defined
The synthesized core–shell polymer emulsions were used as pigment binders in leather finishing application to evaluate the effect of their composition on coating performance
Other authors have obtained controlled particle growth and a small risk of coagulation for latex particles obtained by seeded emulsion polymerization, the synthesis method used in the present study [38]

Summary

Introduction

Leather finishing is regarded as a stepwise process occurring in the final stage of leather manufacturing, and it is considered very important, as the final properties of leather goods such as appearance, coverage of surface defects and scratches, glossiness, feel, touch, color uniformity, fashionable effects, and patterns as well as mechanical and weathering resistance properties are defined. The main factor effecting the appearance and performance of the leather surface is the coating composition. For this purpose, many categories of chemical products are used, i.e., pigments, waxes, binders, lacquers and other auxiliaries. Acrylic latexes play the major role on leather properties, as they are the most widely used binders responsible for the film formation and binding the other additives to leather surfaces. There have been many studies on improving the properties of leather coatings, as the demands for performance levels of leather surfaces are increasing [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15]

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