Synthesis And Characterization Of Free Radical Hyperbranched Polymeric Photoinitiator

UV curing as a kind of radiation curing technology is the rapid development of "green" new technology, widely used in photocurable coatings,photoresist, photocurable ink, electronic packaging materials, and other fields. Photoinitiators ccupy a very important position in the UV curing,which is the most important factor to determine the extent and speed of curing system. Polymeric photoinitiators have been the subject of increasing increast with the advantages of low vlatility,strong ability against migration,good compatibility with environment andresins and diversity in function in recent years. However, at present, many polymeric photoinitiators still result small molecular migration and the initiator activity has yet to be enhanced.Hyperbranched polymers have been the subject of increasing increast at home and abroad in recent years with its advantages of unique spherical structure, low viscosity of coating, curing speed and good film. In this paper, hyperbranched polymer was combined with photoinitiator by modifying the hyperbranched poly(amide-ester) to synthesis two kinds of hyperbranched polymeric potoinitiators.The second generation hyperbranched polymer HBP-2 has been synthesized by the monomer of TMP and DKBA .Using FT-IR and DSC to Characterize the HBP-2 of the structure and thermal sability .The HBP-2 has good solubility, low viscosity and good thermal stability.Hyperbranched polymer HBP-2 was introduced to the compound of 1173 which modified by TDI to synthesis the hyperbranched polymeric photoinitiator HBP-2-TDI-1173. Chemical titration and FT-IR analyses have confirmed the structures of HBP-2-TDI-1173. HBP-2-TDI-1173 has low viscosity and good solubility . UV-vis and fluorescence spectras have been used to study their optical properties. The UV-vis spectra of the polymeric photoinitiator exhibits the maximal absorption red shift. Fluorescence emission spectra of the polymeric photoinitiator is strongger .The conversion rate of NVP photopolymerization is slightly lower.Hyperbranched polymer HBP-2 was introduced to the compounds of 4-BP and DMEA which modified by TDI to synthesis the hyperbranched polymeric photoinitiator HBP-2-TDI-DMEA-4-BP. Chemical titration and FT-IR analyses have been used to confirm the structures of HBP-2-TDI-DMEA-4-BP. HBP-2-TDI-DMEA-4-BP has low viscosity and good solubility .UV-vis and fluorescence spectra shave been used to study their optical properties. The UV-vis spectra of the polymeric photoinitiator exhibits the same absorption. Fluorescence emission spectra of the polymeric photoinitiator is munch weaker. The conversion rate of NVP photopolymerization is slightly strogger.