Synthesis Of Boltorn Hyperbranched Polymeric Photoinitiator

Photoinitiators is an integral part of UV-curing paints. It is one of the main factors that determine the curing effects. The structure of boltorn hyperbranched polymers is unique spherical.the internuclear molecule of them can control molecular polydispersity,molecular weights. So the performance of the product can be controlled well. In recent years, the research and application about boltorn hyperbranched polymers flourishes more and more at home and abroad.In this paper,two kinds of boltorn hyperbranched polyesteramide potoinitiators have been synthesised as follows:In solvent DMAc,the second generation hyperbranched polyesteramide HPEA-2 was synthesized by esterification of DKBA and DER.Two kinds of carboxyl-terminated hyperbranched polyesteramide HPEA-2-MA and HPEA-2-SA were synthesised by modifying HPEA-2 end groups with maleic anhydride(MA) and succinic anhydride(SA).Boltorn hyperbranched polyesteramide potoinitiators HPEA-2-MA-HMPP and HPEA-2-MA-HMPP have been synthesised by grafting photoinitiator HMPP on carboxyl-terminated HPEA-2-MA and HPEA-2-SATwo kinds of carboxyl-terminated photoinitiators HMPP-MA and HMPP-SA were synthesised by modifying photoinitiator HMPP with MA and SA. HPEA-2-MA-HMPP and HPEA-2-SA-HMPP were synthesised by grafting HPEA-2 on carboxyl-terminated photoinitiators HMPP-MA and HMPP-SA.The esterification reactions can be tracked by the acid value successfully.The structures and characteristics of polymers were studied by infrared absorption spectra, DSC,ultraviolet-visible absorption spectra, viscometricmethod and fluorescence spectra. The polymers have highly branched macromolecules, good thermal stability, low viscosity and good solubility. By comparison with HMPP's, UV of HBPE-2-MA-HMPPand HBPE-2-MA-HMPP showed a slight red-shift. Fluorescence emission peaks was stronger thanHMPP.