Synthesis And Properties Ofliquid Rubber Adhesive For Special Optical Films

Optical film is a kind of dielectric material which coated with a thin layer of polymer adhesive layers or metal layers on the optical substrate or the optical element,to change the propagation characteristics of light between the interfaces,thereby realizing light transmission,modulation,conversion and division and synthesis of spectrum or energy.Polymer adhesive is the most important component of optical film,which properties directly determine the performance of optical film.With the diversification requirements of functional optical films,higher requirements are imposed on polymer adhesives.How to synthesize a kind of adhesives Possessing excellent optical properties,mechanical properties,yellowing resistance,low temperature resistance,hydrolysis resistance and self-repairing properties,in order to meet the application of optical films in different fields demands,have attracted wide attention.Hydroxyl-terminated polybutadiene(HTPB)is a kind of hydroxyl-terminated telechelic liquid rubber.It has been widely used in synthetic Excellent overall performance adhesives,owing to it's good transparency,hydrolysis resistance,acid and alkali resistance,low temperature performance and yellowing resistance.In this paper,adhesives HTPB-based polyurethane acrylate(HTPB-PUA),polybutadiene acrylate(PBAM),HTPB-based self-healing polyurethane adhesive(20%UPy-SS-PU)was synthesized.The specific research contents of this paper are as follows:1.Using hydroxyethyl acrylate(HEA),aliphatic isophorone diisocyanate(IPDI)and HTPB as raw materials,di-n-butyltin dilaurate(DBTDL)as catalyst,a colorless transparent and narrow molecular weight distribution HTPB based polyurethane acrylate macromonomer(HTPB-PUA)was synthesized successfully;then HTPB-PUA liquid optical clear adhesive was prepared by mixing with active dilution monomer and photoinitiator 1173;finally UV curing was carried out to prepare a series of UV optical films with different monomer ratios.The structure of HTPB-PUA macromonomers was characterized by 1H-NMR,FTIR and GPC.The optical properties and mechanical properties of UV-cured films were further studied by UV-visible spectrophotometer and universal tensile machine.The results show that the UV-curable optical films with different monomer ratios have excellent optical properties.With the increase of HTPB-PUA macromonomer content,the transmittance of UV-curable optical films increases.When the ratio of HTPB-PUA macromonomer to active dilution monomer is 70:30,the transmittance of UV-curable optical film is close to 100%.Shear strength of the HTPB-PUA adhesive decrease as the macromonomer content increases.The maximum shear strength is 4.38MPa.Therefore,the optical and mechanical properties of the UV-curable optical film can be adjusted by adjusting the ratio of the HTPB-PUA macromonomer.2.A colorless and transparent polybutadiene acrylate macromonomer(PBAM)is synthesized in one-pot using hydroxyl-terminated polybudiene(HTPB)prepared by anionic polymerization,potassium naphthalene,and acryloyl chloride(AC)as raw materials.Subsequentially,liquid optical clear adhesive was prepared through blending PBAM,reactive diluent monomer,and photoinitiator.Finally,a series of colorless and transparent films were prepared by UV-curing process.The structure of the PBAM were characterized by GPC,1H-NMR,FTIR.The optical properties,yellowing resistance,low temperature resistance of UV-cured films were further studied.The results showed that a colorless and transparent PBAM was successfully synthesized.The UV-cured films exhibited excellent optical properties and yellowing resistance property.The transmittance of the cured films were as high as 98%.After 264 hours of accelerated aging exposure to ultraviolet radiation showed that the color difference(?E)is below 1.5.In addition,the cured film also presented good low temperature resistance,and it's glass transition temperature was as low as minus 30 ?.3.A chain extender(UPy-diol)having a side chain containing a UPy group was synthesized using 2-amino-4-hydroxy-6-methylpyrimidine(UPy),4,4'-dicyclohexylmethane diisocyanate(HMDI),2-amino-2-methy1-1,3-propanediol(AMPD)as a raw materials.Subsequentially,HEDS and UPy-diol were used as chain extenders to synthesize HTPB-based disulfide bonds and hydrogen-bonded double self-repairing polyurethane(20%UPy-SS-PU).And compared with polyurethane(SS-PU)containing only disulfide bonds.The effects of the introduction of the UPy Group on the self-healing properties and thermal properties of polyurethanes were investigated.The results showed that after repairing at 50 ? for 2 h,the self-healing efficiency of 20%UPy-SS-PU after repairing at 50 ? for 2 h was 96.8%,higher than SS-PU which containing only disulfide bonds.The introduction of UPy group made the glass transition temperature of the prepared 20%UPy-SS-PU is slightly higher than SS-PU;however,the thermal stability is basically unchanged and the self-healing temperature is lower.