| Rosin is an important renewable natural product. Polymerizable rosin derivatives, which are key research directions recently, can be used in two fields. Firstly, they can be used as promoters, which not only play as addictives, but also used as monomers in the polymerization. Secondly, polymerizable rosin derivatives can be used as a main resource of raw materials to prepare the polymer materials. UV cured coatings were prepared by blending acrylic rosin derivatives with reactive diluents and photoinitiators. In addition, hybrid coatings with optimum properties, could also be prepared by mixing pre-prepared acrylic rosin coating with nanosilica. The preparation, structure and properties of the cured coatings were investigated. The main results are described as follows:UV cured coatings were prepared by using acrylic rosin derivative acrylic rosin (β-acryloxyl ethyl)ester (ARA) as main component, blending with reactive diluent and photoinitiators. Performances during the curing process were characterized by pencil hardness, adhesion and gel content. The result suggested that HEA was compatible with ARA coatings, when HEA acted as the role of reactive diluent, Darocur 1173 as photoinitiator, whose properties could be adjusted by changing the content of HEA. The double bond conversion and surface drying time of ARA/HEA coatings were investigated. Performances of the coatings were also measured by TG, DMA, gel content in the same time. When contained 20% of HEA, the coating had the best comprehension properties: gel content reach 92.3%, pencil hardness is 3H at 60 seconds, adhesion is 1 grade.ARA hybrid coatings were obtained by mixing ARA/HEA with Degussa nanosilica with different particle size and different surface morphologies. Effect of particle size and surface morphologies on the ARA/HEA coatings were investigated by measuring their chemical resistance. In the condition of hydrophilic nano-silica, the water resistance was poor. In contrast, cured coating membrane showed good chemical resistance, passed through GB/T 1763-1989, with the addition of hydropholic nano SiO2, DMA curve showed that, storage modulus of hybrid coating membrane was much better than that of normal membrane at the room temperature. SEM and TEM images suggested that organic-inorganic was not totally compatible, and phase separation is observed at micro level.Nano silica sols with various particle sizes were prepared by stober method. TEOS was firstly hydrolyzed with NH3 as the catalyst, then modified by 3-trimethoxysilylylpropyl(MATS). Particle size, surface modified condition, thermal analysis were also executed. MATS is grafted on the surface of the nano silica. With the addition of NH3, the particle size increased, while particle distribution narrowed. The thermal resistance of MATS was significantly increased because of the existence of nano silica.The MATS modified nano silica was condensed by evaporated most of the ethanol, and the residual free MATS as the dispersing media. ARA/HEA and MATS modified nano silica hybrid coatings were prepared by adding the concentrated MATS modified nano silica into the ARA/HEA coatings. Improved inorganic-organic dispersion state was observed. Between the inorganic and organic phase, a transition phase was existed. Gel content increased from 92.3% to 95.4%. Thermal analysis such as TG and DSC are performed as well. Compared to the normal cured membranes, glass transition temperature and thermal gravimetric temperature of hybrid coating are increased. The pencil hardness was also improved from 2H to 3H, adhesion stayed in the 1 grade, and chemical resistance remained passed the GB/T 1763-1989. |
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