Preparation And Properties Study Of Polyurethane Acrylate Coatings

Currently, there are lots of studies using the polyurethane oligomer to prepare coating materials. At present, a lot of defects exist in these materials, such as longer curing time of coating, poorer gel rate and water resistance, bigger shrinkage rate, more organicvolatile solvent, unable to get requirements of environmental peotection. In view of the above mentioned problems, we have prepareed a kind of light-cured color coating material for color coil paint, in which polyurethane acrylate oligomer acts as oligomer, oily pigments as fillers, and hydroxyl acrylate as reactive diluents.we have firstly prepared the polyurethane with MDI?PEG 1000 and PEG200 as raw materials, Through polymerizetion reaction with reactive diluents, the polyurethane has been grafted with the C=C group using 1173 as the initiator, and the color fillers has been uniformly dispersed in the polymer matrix. The structure and properties of oligomer, the distribution of fillers, and the coating performance of the product has been tested using FT-IR?TG?SEM and tensile stress. It is shown that the curing time of coating is 92s, the solid content is 97%, hardness is 4H,shrinkage rate is 8.05%,the tensile strength is 17.2 MPa,flexibility is 2mm, and the adhesion is 2 levels. The coating has preliminaryly meet the requirements. In particular, the organic solvent content in the product has been dramatically reduces to meet the requirement of green environmental protection.In order to further improve the coating performance,we have then designed new polymer conformation to reduce the density variation before and after grafting chain reaction. A HBP3 has been prepared on the condition of 145? using TMP?DMPA as monomer and P-TSA as catalyst.The HBP3 has been grafted to the half polyurethane acrylates. After adding active diluents, light initiator and fillers,the reaction forms three-dimensional network connectionto avoid linear coupling, and therefore to ensure that stable stacking density.By using FT-IR?TG?DSC and tensile stress, the structure and properties has bee retested. The curing time of coating is 83s, the solid content is 97.8%, hardness is 5H, shrinkage rate is 2.48%, the tensile strength is 20.1MPa, flexibility is 1mm, the adhesion is 1 levels.The results indicated that the comprehensive performance of the coating has been extensively improved to meet the industrial requirement.