Studies On Synthesis And Properties Of Polysiloxanes Urethane Diarylate Oligomers

Polysiloxanes present well-known peculiar characteristics such as weather stability, excellent insulation property, hydrophobicity, chemical resistance, low surface energy and low interface tension. Because of their excellent properties, polysiloxanes are used in many specialty areas, such as electronic industry, printing industry, etc. Ultraviolet (UV) curing is a new technology which had advantages of curing fast, energy-saving and environmental protection, and was developed rapidly in recent years. The aim of paper is synthesizing different polysiloxanes urethane diarcylate oligomers which are used in UV-curing material, and studying the relation and rule between properties and structure. And that can be theory and technical assistant for expanding UV-curing polysiloxanes application areas.In this paper, series of UV-curing polysiloxanes urethane diacrylate oligomers were synthesized and characters of these oligomers were studied, the specific work was as follows:(1) The influences, of adding reactants way, reagents, reaction temperature, catalyst, solvent and inhibitor on reaction rate and oligomer structure were discussed in detail, and the best reaction conditions were confirmed. Ten different polysiloxanes urethane di(methyl)acrylate oligomers were characterized by IR, GPC and ~1H-NMR.(2) The effect of UV photoinitiators, reactive monomers and structure of oligomers on the photosensitivity of the systems was investigated by RTIR. The results showed that TPO and 1700 were the best photoinitiators among those tested, and their optimal concentration was 0.5%-l% (wt.%). The influences of structure and concentration of reactive monomers on C=C conversion and C=C conversion rate were discussed in detail. The effect of different oligomers on the photosensitivity was also studied. It was confirmed that oligomers synthesized in this paper can photopolymerize under UV irradiation in the presence of photoinitiators,(3) The physical and mechanical properties of UV-cured coating, such as surface property, water resistance, chemical resistance, tensile strength, hardness, toughness, adhesion, thermal property, Tg and so on, and relation between structure and property were systemically explored. The contact angle of coating can reach 103°; toughness can reach 1mm; thermal property was good that it just lost mass of 4.61% at 300℃(the oversea oligomer OAK27 was 7.61%, OAK12 was 25.79%); tensile strength and elongation were also excellent, and they were 14.41MPa and 61.04%, respectiveily. Good chemical resistance and lower absorption of water were also hold by UV-cured coating. Tg of coating were in the range of 50℃-80℃.