Study On Synthesis Of Polyacrylates And Their Application As Pressure-sensitive Adhesive

Acrylate is an important category of viscoelasticity and is widely used in applications dues to its excellent adhesive character, mechanical character, chemical stability, innocuity and low cost. But the recent acrylate is not suitable for some special industry application because of its weak resistance to acid and alkali, weak chemical stability, and weak repetitive-use character, which are caused by its composition and segment structure. Thus improving its adhesive performance becomes a critical field in fundamental researches and applications of acrylate. In this thesis, we prepared modified acrylate by solution method, using epoxy or organic silicon as modifiers, and studied the effect of reaction conditions on adhesive character. Mechanism of improving adhesive character was also investigated systematically.Copolymer based on butyl acrylate (BA) and methyl acrylate (MA) was prepared using solution method and charactered by ~1H-NMR and GPC. Using Kelen-Tudos method, the reactivity ratios of monomers were calculated. The effect of polymerization conditions such as temperature, time, amount of the monomers, and feeding method on molecular weight (MW), molecular weight distribution (MWD), composites and adhesive performance of resultant copolymers were investigated. It is found that the best reaction conditions are as follows: ethyl acetate (EA) as solvent, AIBN as initiator, BA/MA molar ratio 2:1, reaction temperature 78°C, reaction time 7h.Copolymer based on butyl acrylate, methyl acrylate and acryl acid (AA) was prepared using solution method and charactered by ~1H-NMR and GPC. The effect of different polymerization conditions on molecular weight, molecular weight distribution and adhesive performance were investigated. It is found that the hydrogen bond introduced by AA results in a physical cross-linked structure and improves the adhesive performance.The modified acrylate was prepared with epoxy in different phase states, as fluid phase and solid phase respectively, and charactered by GPC, DSC, DMA and contact angle. The reaction heat was studied to know the curing reaction kinetics and molecular chain mobility. The influence of molecular parameters on cross-link network and surface adsorptive capacity, further more, the adhesive character, was also investigated, which were caused by cross-linkers with different chain length. It is found that the changes of structure of cross-link network affect the surface and bulk character of copolymer, further more, the adhesive properties.Copolymer based on butyl acrylate, methyl acrylate and organic silicon was prepared using solution method. The effect of polymerization conditions such as temperature, time, amount of the monomers on adhesive performance of resultant copolymers were investigated. It is found that the best reaction conditions are as follows: EA as solvent, AIBN as initiator, BA/MA molar ratio 2:1, proper quantities organic silicon, reaction temperature 78°C, reaction time 7h;proper quantities triethylamine, EA as solvent.