偶联剂对丙烯酸酯改性聚氨酯聚合物接枝率和乳液性能的影响

合成了含双羟基的甲基丙烯酸甘油酯(GM)并将其作为偶联剂用于聚丙烯酸酯(PAC)对水基聚氨酯(PU)的改性.采用核磁共振、红外光谱和气相色谱等对GM进行了表征.分别以该双羟基GM和单羟基的丙烯酸羟乙酯(HEA)与异氰酸酯基(NCO)封端的PU预聚体进行反应以在PU分子链上引入双键,然后再与丙烯酸酯类单体通过自由基聚合制...

INFLUENCE OF COUPLING AGENT ON GRAFTING IN ACRYLICS POLYURETHANE POLYMERS AND PROPERTIES OF THE HYBRID LATEX

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 13 C-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 GMa,nd 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 agentsr,esults 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 GMt,he 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 1t,he molecular weight of the vinyl attached PU increased,and a decrease was detected when OH /NCO was superior to 1.For both coupling agentst,he 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.