Preparation And Modification Of Hyperbranched Poly(Ethylene Glycol Dimethacrylate-amine)

Hyperbranched polymer is a kind of polymer materials with high functionality and multipurpose.When hyperbranched polymer cannot meet some requirements,it can be grafted with multifunctional group materials in its end group to increase the performance of hyperbranched polymer.In this paper,a new method to synthesize hyperbranched polymer using commercial A2 and BB?2 monomers by Michael addition is proposed.In the paper,amino ethyl piperazine and ethylene glycol dimethacrylate were used to prepare hyperbranched poly(ester-amine)with amino terminal group without catalyst.However,its lack of hydrophobic functional groups led to poor hydrophobicity,which restricted its application in the coating field.Therefore,in order to improve hydrophobicity and expand its application in coating field,the hyperbranched poly(ester-amine)was modified by dodecyl fluorohepthy methacrylate(MBFA-12)to obtain hyperbranched poly(ester-amine-MBFA-12).Hyperbranched poly(ester-amine-MBFA-12)as a binder mixed with nano-Si O2 to prepare super hydrophobic coating.(1)Hyperbranched poly(ester-amine)was synthesized,its structure was characterized by fourier infrared(FI-IR)and ~1H NMR,and the amine value was titrated to track the reaction process.The effect of reaction time on the degree of branching of hyperbranched poly(ester-amine)was studied.It was found that the degree of branching increased with the increase of reaction time and reached 0.73 when the reaction time was 60 h.Then isophorone diisocyanate(IPDI)was used to prepare the two-component poly(ester-amine)coating.It was found that the coating had good adhesion and pencil hardness.The hydrophobicity of the two-component poly(ester-amine)coating was not very high,the highest contact angle of the coating was 87.5°.(2)Poly(ester-amine-60)was selected to modify the end amino group,and the molar ratios of poly(ester-amine-60)and MBFA-12 were changed,namely 1:0.4?1:0.45?1:0.5?1:0.55?1:0.6 to obtain five different products,and then mixed with IPDI to prepared the coating.The structural,the surface element and glass transition temperature of poly(ester-amine-MBFA-12)coating were characterized by FI-IR,XPS and DSC,respectively.It was found that the coating had good adhesion,but the hardness of the pencil decreased with the increase of the content of MBFA-12,but the hydrophobicity of the coating became better,and the highest contact angle of the coating was 118°.(3)3%and 5%of nano-Si O2 relative to hyperbranched poly(ester-amine-MBFA-12)mixed with IPDI to prepared the coating.The surface morphology of coating was observed by SEM,and the acid and alkali resistance of coating were tested.The results showed that there were a large number of microscopic particles and pores on the surface of the coating,the acid resistance of the coating was weak,but the alkali resistance was good,and the hydrophobicity of the coating was high and the highest contact angle of the coating could reach 154.8°.