Architectural membrane modification and UV coating properties
|School||Zhejiang University of Technology|
|Keywords||PVC membrane coating anti-UV property thermal stability property rheology property Whiteness Impact Strength the quadratic general rotary unitized design|
In recent years, the ozone layer appears more and more large holes with the increasing environmental pollution, a large number of ultraviolet expose to the surface of earth through the holes,and affect human health seriously. Accordingly, the research and development of anti-UV production has become a major issue needed to be resolved.According to the UV mechanism, the PVC membrane structure materials were prepared with the solution blending method, which including matrix material of PVC paste resin （PVC）, plasticizer of isononyl phthalate ester （DINP）, heat stabilizers of Ba-Zn and filler of ultra-fine/ superfine heavy quality of CaCO3, the anti-ultraviolet performance was improved by adding nano SiO2, nano TiO2, nano ZnO, UV-531 and other inorganic/organic anti-ultraviolet agent, and study the variation of the PVC membrane structure materials’whiteness and impact strength. In the study, the material’s rheololgy property, impact strength property, distribution of particals, anti-UV property and thermal stability property were studied. Firstly, the thermal stability property and rhelolgy property were studied by changing the content of DINP, Ba-Zn and CaCO3, and the the coating concentration of various additives were optimized. Secondly, based on the optimizing coating additives of PVC membranes, the anti-UV property was studied by adding different content of nano SiO2, nano TiO2, nano ZnO and UV-531, so as to optimize the three inorganic UV agent, determine the optimal content of the inorganic UV agent, the variation of the PVC membrane structure materials’whiteness and impact strength were studied as well. The main conclusions were as follows:（1） Study on the rheololgy property of PVC coating: the PVC membrane structure materials were prepared with the solution blending method. The goal of the testing of viscosity, MI and rheology properties as well, is to conform to the various standards.The results indicated that the PVC membrane structure materials conformed the standard when the content of DINP is 30%, bur the viscosity reduced when increased the content of DINP, the viscosity of coating had bigger reduction when the content of DINP is 33%.The MI value increased firstly, then reduced, and increased finally with the increasing of additives.The MI came to the maximum when the content of DINP is 33%, and the coating had good processing performance at this time; The MI came to the minimum when the content of DINP is 37%, and the coating had worse processing performance at this time.The influence of the content of Ba-Zn to viscosity and MI is big, the viscosity came to the minimum but the MI came to higher value when the content of Ba-Zn is 1.2%. The variation of Angular Frequency and content of CaCO3 with Storage Modulus, Loss Modulus, Torque, Damping Factor and Complex Viscosity were tested when adding different kinds of CaCO3 （superfine heavy CaCO3 and nanometer active CaCO3）. The results indicated that Storage Modulus, Loss Modulus and Torque increased gradually; Damping Factor increased sharply before leveling off; Complex Viscosity decreased sharply before leveling off, the rheology property changed greatly with the increasing content of CaCO3.（2）Study on the thermal stability and surface morphology of PVC membrane coating: Under the condition of same content of DINP, the thermal stability of PVC membrane coating was studied by changing the content of Ba-Zn, the results indicated that the heat flow was increased significantly when adding Ba-Zn in the PVC coatings, the average rate was 4060J/g, and the PVC resin happened“zinc burning”and“zinc burning”phenomenon when the temperature was 283℃. The PVC proned to agglomeration when added nanometer active CaCO3 in it, the agglomeration can reduced when processing of the nanometer active CaCO3/ethanol blends by using of ultrasound method, and the particle size reduced by the 4.733μm and 4.137μm, the dispersion and uniformity of nanometer active CaCO3 had been increased after the ultrasound method.（3）Study on the anti-UV property of PVC membrane coatings: The anti-UV property could improved when adding inorganic UV agent （nano SiO2, nano TiO2 and nano ZnO） and organic anti-UV agent （UV-531） in the PVC membrane coatings, in comparison, the anti-UV property when added inorganic UV agent in the coating was worse than the coating that adding organic anti-UV agent, but the stability was better.When the organic anti-UV agent was added to the coatings,the anti-UV property was good, but the stability was poor, the organic particles easily highlight in the coating surface, and the particles easily leaving off with the influence of water, heat, ultraviolet light and so on, resulting in the effect of anti-UV property worse. The anti-UV property had a great change when adding different inorganic UV agents （nano SiO2, nano TiO2 and nano ZnO）, the results indicated that the mechanical properties improved significantly when added nano SiO2 in the coatings.Under the condition of same content, the anti-UV property improved better when adding nano TiO2 in the coatings. （4）The effect of UV to PVC coatings’whiteness and impact strength:the whiteness and mechanical properties decreased when the PVC membrane coating irradiated with UV light. The quadratic general rotary unitized design with three factors which were the time of UV irradiation, the intensity of UV irradiation and the content of nano SiO2,the level of factors were -1.682, -1, 0, 1, and1.682,was used to study the influence of UV irradiation on the whitenss and impact strength of nano SiO2 /PVC membranes. The experimental results indicated that the whiteness and impact strength improved when increasing nano SiO2 content,but reduced when increasing the treated time and strength of UV.