Xu JW, Pang WM, Shi WF (2006) Synthesis of UV-curable organic-inorganic hybrid urethane acrylates and properties of cured films. Thin Solid Films 514(1-2), 69-75. [In English]

Web link:http://dx.doi.org/10.1016/j.tsf.2006.02.032

Keywords:

coatings, silane, organic-inorganic, nuclear magnetic, resonance, hardness, urethane acrylates, thermo gravimetry, sol-gel, coatings, polymerization, polycarbonate,

Abstract: An organic-inorganic hybrid urethane acrylate hydrolytic condensate (HUA-HC) was prepared through sot-gel method with an acid catalyst of low concentration from a hybrid urethane acrylate prepolymer (HUA), which is a disfunctional silane containing hydrolysable ethoxysilane groups (Si-OEt). The synthesis was monitored by Fourier-transformed infrared spectroscopy, H-1 nuclear magnetic resonance (NMR), 13 C NMR and Si-29 NMR. The photopolymerization kinetics studied by photo differential scanning calorimetry showed that HUA-HC had a faster apparent photopolymerizaton rate and a higher conversion of double bonds than HUA under 72 degrees C due to the vicinity of double bonds in HUA-HC. However, HUA-HC showed a slower apparent photopolymerizaton rate and a lower conversion of double bonds than HUA at higher temperatures above 72 degrees C, which indirectly indicates that more extensive condensation between ethoxysilane (Si-OEt) and silanol (Si-OH) groups in HUA-HC than that in HUA. Both 100-mu m-thick films of HUA-HC and HUA cured by ultraviolet (UV) light showed high pencil hardness (>, 4 H) and excellent abrasion resistance (<, 40mg after 600 cycles). 2-mm-thick specimen of HUA-HC and HUA cured by UV light showed high tensile strength (>, 30 Wa). The cured HUA-HC film showed better performance than the cured HUA film in the investigated aspects due to more inorganic Si-O-Si linkages in HUA-HC, which is also the reason that HUA-HC film had higher decomposition temperatures and more residue than HUA in thermal gravity analysis. (c) 2006 Elsevier B.V. All rights reserved.