Preparation and Optimization of Waterborne Acrylic Core Microcapsules for Waterborne Wood Coatings and Comparison with Epoxy Resin Core.

Xiaoxing Yan,Xingyu Qian,Yu Tao

doi:10.3390/polym12102366

Abstract

Microcapsules were prepared by in situ polymerization with urea formaldehyde resin as the wall material and Dulux waterborne acrylic acid as the core material. The effects of the core–wall ratio, water bath temperature and depositing time on the morphology, particle size, yield and encapsulation ratio of microcapsules were investigated by orthogonal experiment of three factors and two levels. The results showed that the core–wall ratio had the greatest influence on the performance of microcapsules. When the core–wall ratio was 0.58:1, the water bath temperature was 70 °C, and the depositing time was 5 d, the microcapsule performance was the best. With the increase in depositing time, the yield of microcapsule particles increased gradually, and the microcapsules appeared to show an adhesive phenomenon. However, the long-term depositing time did not lead to complete deposition and agglomeration of microcapsules. When 10.0% concentration of the waterborne acrylic microcapsules with 0.58:1 of core–wall ratio was added to the coatings, the mechanical and optical properties of the coatings did not decrease significantly, but the elongation at break increased significantly. Therefore, this study offers a new prospect for using waterborne acrylic microcapsules to improve the toughness of waterborne paint film which can be cured at room temperature on a wood surface.

Highlights

Microcapsule technology is a kind of packaging technology that uses natural or synthetic polymer film-forming materials to coat gas, liquid or solid into 1–1000-μm micro particles [1]
The results showed that the coating with epoxy resin had better elongation at break showed that the coating with epoxy resin had better elongation at break than that with waterborne than that with waterborne acrylic microcapsule, which may be due to the fact that the flexibility of acrylic microcapsule, which may be due to the fact that the flexibility of waterborne acrylic resin is not waterborne acrylic resin is not as good as that of epoxy resin, so the elongation at break was low
The influences of the three factors on the yield, encapsulation ratio, particle size and morphology of microcapsules are explored to determine the preferred level of 70 ◦ C water bath temperature and 5 d depositing time

Summary

Introduction

Microcapsule technology is a kind of packaging technology that uses natural or synthetic polymer film-forming materials to coat gas, liquid or solid into 1–1000-μm micro particles [1]. Microcapsules are generally composed of a wall material (wrapping material) and core material (wrapped material). The wall material determines the strength of microcapsules, the release characteristics of sustained-release core materials and the durability of microcapsules, which has an important impact on the performance of microcapsules [2]. Microencapsulation technology has experienced a long development process, and has been widely used in the fields of medical treatment [3], cosmetics, food, textile, coating and advanced materials. Self-healing technology, as a new effective way to suppress coating micro-cracks, has become a research hotspot in many application fields [7,8,9]

Methods

Results

Conclusion