Uv Curing Of Hyperbranched Polyurethane Acrylate Synthesis, Characterization And Properties Of Research

Hyperbranched polyurethane not only has the feature of hyperbranched structure polymer, but also shows the excellent performance of polyurethane, combining those two characteristics makes it has great potential applications in functional polymer materials. This paper adopted coupling monomer method, chain extenders were introduced in the synthesis process, hyperbranched polyurethane of different generation and different system were synthesised, the structure and properties of multi-generation hyperbranched polyurethane were studied too;the fourth-generation of hyperbranched polyurethane was chosen to be modified. UV-curable hyperbranched polyurethane acrylate was synthesised. a series of characterization and testing were conducted,exploring the relationship between the structure and properties of UV-curable hyperbranched polyurethane acrylate. later. UV-curable hyperbranched polyurethane acrylate was added into bisphenol A epoxy acrylate to blend and coating,exploring the performance of the coatings.The main work is as follows:1、the research of the synthesis of hyperbranched polyurethaneIsophorone diisocyanate、1,4-butanediol、1,6-hexanediol、polyether polyols and diethanolamine were as raw materials, adpoted coupling monomer method, by measuring the value of NCO of the reaction system, controling the reaction process, hyperbranched polyurethane of different generation and different system were synthesized(HBPU-X-n. the X was the species of chain extenders which were introduced, the n was the generation of product), the reaction product was colorless transparent liquid and the white powder was obtained after separation and purification.The product was characterized by Fourier transform infrared spectrometer (FT-IR)and Nuclear magnetic resonance spectroscopy(NMR). The results showed that:all product had the structure of hyperbranched polymer, and the degree of branching was up to90%.2、the research of the structure and properties of HBPU-X-nTG and DSC were adopted to explain the process of thermal decomposition and the glass transition temperature (Tg) of the product obtained, respectively. The results showed that:the obtained HBPU of each system had the same initial decomposition temperature (about at200℃); with the increase of the length of chain extenders, the Tg of the second-generation HBPU in different system decreased from107.2℃to30.2℃, however, the Tg of the obtained HBPU in the same system increased with the increase of the generation, yet the change in the third-generation and the fourth-generation was rather small; in the weakly polar solvents, the solubility of HBPU increased with the increase of the length of chain extenders, yet decreased with the increase of generation; by constrasting the coatings we can find that:the adhesion increased from4to0and the flexibility increased from4to1.3、the research of the synthesis of the UV-curable hyperbranched urethane acrylateHydroxyethyl methacrylate was chosen to be double bond in the introduction agent. the obtained HBPU-X was suffered from end-group modified, series of the UV-curable hyperbranched urethane acrylate (HBPUA-X) containing the UV-curable groups were synthesised,the reaction product was colorless transparent liquid and the white powder was obtained after separation and purification.4、the research of the structure and properties of HBPUA-XTG、DSC and Ubbelohde viscometer were adopted to demonstrate the structure and properties of products. Then, HBPUA was added into light-cured epoxy acrylate to get cured film, the effect of the dosage on coating performance was studied. The results showed that:when the concentration of product was less than12%,the intrinsic viscosity changed obviously with the increase of the length of chain extenders;the coatings displayed that:as the addition dosage of HBPUA-HDO is10%, the adhesion increased from3to1and the flexibility increased from8to2;as the addition dosage of HBPUA-PEG400is10%, the adhesion increased from3to0and the flexibility increased from8to1; the introduction of HBPUA-X can improve the hardness of pendulum and the impact strength.