Preparation Of Acrylate Pressure Sensitive Advensive By UV Bulk Polymerization

Solution polymerization and emulsion polymerization are used as the common preparation methods of pressure-sensitive adhesives(PSA),while both of the methods need the raw materials to be polymerized under heating conditions for more than 7 hours,the time limit for the temperature rise and fall of the polymerization reaction determines that the reaction rate is difficult to control.In the latter part of the reaction,it takes a lot of energy to remove the solvent or water from the product,which leads to unnecessary waste of resources.UV bulk polymerization of pressure-sensitive adhesive is a new type of energy efficient polymerization which is initiated by photoinitiator with UV LED light.The way has a notable feature that this kind of aggregation is very efficient and has 100 solid content still with the advantages of fast reaction rate,controllable reaction degree,colorless and transparent,little influence of temperature and good adhesion and weathering resistance.etc.This subject mainly includes the study of the mechanism of UV initiation and the purpose of controlling the performance of the product by studying the relationship between reaction conditions and product performance.This experiment mainly includes two parts: polymer performance research and process control.Performance studies include preparation of prepolymers and curing of pressure sensitive adhesives.The initiator produces free radicals under the action of UV LED light and initiates polymerization of various acrylate monomers.The selection of various soft and hard monomers are preliminarily determined by studying the photopolymerization rate of various acrylic monomers.The composition and ratio of each component of PSA,the molecular weight and distribution of the polymer under the optimum composition were determined by changing the different ratio of soft and hard monomer and also different initiator contents.During the preparation of prepolymer,the viscosity of the prepolymer is controlled by the light time.It is just in the automatic acceleration stage of the polymerization reaction when the prepolymer reaction is over,so if the light time is slightly prolonged,the detonation reaction will occur in the actual industrial production process.In order to improve the safety factor of the industrial production,intermittent illumination is adopted to control the reaction time and reaction times of each polymerization so as to achieve the desired viscosity.UV-curable pressure-sensitive adhesive can be obtained by adding proper initiator and crosslinking agent into the prepolymer.The effects of the type and amount of initiator,the intensity of curing light and the time of light on the mechanical properties were investigated,and the effects of crosslinking agent,isocyanate and acrylic acid on the heat resistance and aging resistance were also studied.