Study On The Reaction Of PVAc With MDI

Polyvinyl acretate (PVAc) and copolymer of vinyl acretate and hydroxyethyl acrylate(VAc-co-HEA) were respectively synthesized by solvent polymerization and emulsionpolymerization; the reactions of PVAc and PVAc-co-HEA with diphenyl methanediisocyanate (MDI) were also investigated. The structures of resultant polymers werecharacterized by GPC, ~1HNMR and IR. The influence of HEA and MDI ratio on PVAcadhesive strength was mainly discussed .The results showed that both in solventpolymerization system and emulsion polymerization system, the adhesive strength ofmodified PVAc was enhanced by adding a little of HEA, the adhesive strength raised morewith the concentration of HEA, however the cured time was lengthened. When a littleamount of curing agent MDI was added to the PVAc adhesive system, the adhesivestrength raised more with the concentration of MDI. The hypothesis put forward is thatthere were living reactive grads between the reactions of different hydroxyl with MDI,which is the base of this exoeriment.