Dihydroxyl containing glyceryl methacrylate (GM)

a coupling agent in polyurethane (PU) modification by acrylic polymers (PAC)

was first synthesized through hydrolysis of glycidyl methacrylate

and its structure was confirmed through 13C-NMR

FTIR and gas chromatography.GM was then reacted with isocyanate terminated PU prepolymers to input vinyl group with objective to conduct graft-polymerization with acrylics in a subsequent step

and to get acrylic modified polyurethane (PU-AC) latexes.Hydroxyethyl acrylate (HEA) was also used in the same way as GM

and the results were compared.The results showed that

under the same reaction temperature for PU with the 2 coupling agents

higher NCO conversion combined with a lower grafting of PU to PAC was observed with GM.As regard to the influence of temperature in the reaction of PU with the coupling agents

results indicated that both NCO conversion and PU grafted to PAC in the final latex polymers were increased with increasing the reaction temperature

regardless of using GM or HEA.The molecular weight of the PU prepolymers remained nearly constant upon reaction of PU with HEA

and a slight increase in the particle size in the final PUAC latex was detected.However

with GM

the impact of this reaction temperature on the PU prepolymers was different from that with HEA.With GM

when OH/NCO molar ratio was inferior to 1

the molecular weight of the vinyl attached PU increased

and a decrease was detected when OH/NCO was superior to 1.For both coupling agents

the grafting of PU to PAC was enhanced with more coupling agent when OH/NCO was inferior to 1

and this enhancement was nearly disappeared when OH/NCO molar ration was superior to 1.