Synthesis and characterization of organosilicon modified self-matting acrylate polymer: Insight into surface roughness and microphase separation behavior

摘要

A new type of low gloss waterborne self-matting acrylate polymer with core-shell structure was successfully synthesized. The organosilane Upsilon-methacryloxy propyl trimethoxyl silane (Upsilon-MPS) was used as a crosslinking agent, which can control and modulate the surface micro-roughness of acrylate polymer films. The self-matting acrylate polymer has good latex stability containing no external powdery matting agent. In particular, the gloss value can reach as low as 6.3 units at an incident of 60 degrees when the amount of Upsilon-MPS is 7% based on the total mass of the shell monomer. Moreover, the main factors affecting glossiness, such as crosslinking degree, surface roughness, migration of organosilicon moieties to the surface and phase separation, were studied in detail. The observation by scanning electron microscope and atomic force microscope indicated that the surface roughness was elevated with the increase of the Upsilon-MPS content. Besides, the transmission electron microscope observation and differential scanning calorimeter analysis revealed that the acrylate polymers displayed microphase separation behavior, which combined with the surface roughness could increase the scattered and diffused lights, thereby endowing the coating with the matte effect. In addition, due to the incorporation of Upsilon-MPS, the crosslinking density and hydrophobicity increased, and thereby thermal stability, tensile strength and water resistance of the films were also improved. Therefore, this work provides practical prospects for the industrial application of organosilicon modified acrylate polymer in the field of matte coatings.