Preparation And Properties Of Polysetherglycols PUA UV-curable Adhesives

UV-curable adhesive is a new class of adhesive which used UV-curing technology to achieve fast curing. As the prepolymer is the main components of UV-curable adhesive, its types, molecular structure, molecular weight of urethane acrylates prepolymer body decided toughness, plasticity, curing shrinkage and adhesive properties and basic properties of adhesive. Study the influence of different polyether (soft section) polyurethane acrylates prepolymerization body on properties of the mechanics, optical, thermal of adhesive, which has important meaning on developing and designing good general properties of the UV-curable adhesive.In this paper, A series of polyurethane acrylate prepolymer that had different structure were synthesized from isophorone diisocyanate(IPDI), hydroxyethyl acrylate(HEA), and polymeric glycol, in two different route, UV-curable adhesive can be prepared by blending these polyurethane acrylate prepolymer with other accessory ingredient. Tested the prepolymer, study on The relationship between the different synthesize process and the prepolymer's properties such as viscosity, molecular weight and color. The effect of some ingredient and prepolymer on properties of adhesive, and optimize curing process was discussed.The experiment show: the prepolymer have width molecular weight distribution, high viscosity, in the process of"Polymeric glycol + Diisocyanate→PU prepolymer(contain—NCO) + hydroxy acrylate→PUA". The bonding strength of the adhesive was higher, the soft segment of which was polyester. The flexility of adhesive was better, the soft segment of which was polyether. While the molecular weight of PEG was increasing, the transmittance of cured adhesive decreased; when the molecular weight of PEG was less than 1000, the transmittance didn't change. The bigger the molecular weight of PEG is, the lower the glass transition temperature is. TG analysis indicated that the molecular weight of PEG didn't influence the thermal stability of adhesive. The shear strength decreased, with increasing of molecular weight of PEG. When the molecular weight of PEG was 600, the shear strength reached 1547N, and the main body of adhesive destructed. The structure of prepolymer has a major effect on the performance of light curing adhesive, when the soft period of prepolymer is more than 2000,the molecular transmittance is inferior, when Molecular weight is below 400, glass transition temperature is higher, and the rubber of adhesive is hard and brittle, which effects its usage scope. When the molecular weight of soft segment was used is 600-1000, the property of adhesive such as the transmittance and adhesive strength is excellent, and use temperature is wide, thermal stability is high.The curing process of adhesive was discussed. The result showed that when the times of radiate were 3 minute, the adhesive could absolutely cure. And when the time of radiate prolonged, the properties of adhesive weren't change. light-heat dual curing can cure adhesive after light radiate, and contrasting UV curing system, the properties of adhesive were similar. Dual curing has extended the application area of UV curing adhesive.