Preparation of Aqueous Polyurethane and Its Adhesion to Laminated Films
|School||Nanjing University of Technology|
|Keywords||Waterborne Polyurethane T-peel strength Self-emulsifying Composite films|
Acrylate , β-hydroxy ethyl acrylate ( HEA ) , MDI, polybutylene adipate , 1,4 - butanediol, the diol (or poly - propylene oxide diol N220 ) , dimethylol propionic acid and acrylic acid ester as raw material synthesis of self-emulsifying polyurethane - acrylate (PUA) hybrid emulsion . The effects of the content of butyl acrylate , as well as the ratio of MDI / HEA (mol / mol) the influence on the the PUA latex particle size, particle size distribution and emulsion stability . Compared the compatibility copolymer the PUA and blend PUA . The PUA emulsion as a composite film adhesive , it was found with increasing BA content , the composite film of the T-peel strength is significantly reduced . When adding different crosslinkers , have different effects on T-peel strength . This article also synthesized with acetone a solid content of 35% of the aqueous polyurethane (PU) adhesive , the main raw material include MDI, polybutylene adipate 1,4 - butanediol ester diol ( PBA ) is polypropyleneoxide alcohol the N204/N210 well the DMPA . The particle size of the aqueous polyurethane , storage stability, viscosity ; effects of the PU film of the water resistance and hardness , tensile properties and thermal behavior ; also studied the aqueous PU adhesive action of the adhesive on the PET / PE film . The results show that : when a carboxyl group (-COOH) in the weight percent solids content of more than 0.87% , aqueous PU able to guarantee the storage stability of more than six months . The hydrophilic group content of the higher benefit the stability of the aqueous polyurethane , but the carboxyl group content is too high , the film is not water resistant . The aqueous PU viscosity and the content of the carboxyl group (-COOH) , the neutralization degree and the temperature and other factors . Influenced by the degree of neutralization of the -COOH of the particle size of the aqueous polyurethane system , the higher the degree of neutralization , the smaller the particle size . DSC curves of the water-based PU film , inferred aggregation structure : the hard segment orderly but amorphous , partially crystalline soft segment ; degree of micro-phase separation between soft and hard segments . The PBA and N204 compounded by a certain percentage , you can improve the T-peel strength , improve water resistance . Hard segment content and ionic group content is higher, the greater the film hardness . But when the added supple N204 , hardness will decline . With the increase in the content of -COOH , N204/PBA ratio increases, the upward trend in tensile strength .