At the present time coating industry is devoting much research in the direction of low volatile organic compounds to make eco-friendly coating material. In this study, such materials are developed from cellulose derived from bagasse, a sugar industry waste. Cellulose is converted to cellulose glycoglycoside by acid hydrolysis of cellulose under heterogeneous condition. Cellulose glycoglycoside is treated with polyethylene glycol having different molecular weights to give glycoglycosides which in turn are reacted with various diisocyanates to obtain polyurethane having free NCO groups. These materials are then reacted with hydroxyethylmethacrylate (HEMA) to give polyurethane acrylates. The acrylates are characterized for specific gravity, viscosity, colour and molecular weight as well as by FTIR spectroscopy. The UV-curable coating composition was prepared by blending PU-acrylate, reactive diluents and photoinitiator. Coating compositions were cured under UV-light and characterized for adhesion, flexibility, impact resistance, solvent resistance and for dynamic mechanical analysis as well as by TGA for thermal stability. The cured films give thickness of 23-24 microns and cure time required is less than 1.5-2.0 min. There is no liberation of any volatiles during curing and films have good adhesion to mild steel substrate. The cured coatings give excellent dynamic, mechanical and chemical properties. The scratch resistance was found to be satisfactory. The application was made in unpigmented form but it is found that various pigments can be used to give coloured UV-curable coatings.

New UV-curable di-functional naphthyl epoxy acrylates (DNEA) and multifunctional naphthyl epoxy acrylates (MNEA) were synthesized from naphthyl epoxy, acrylic acid, and hydroquinone as an inhibitor, and N,N´-dimethylbenzylamine (DMBA) as a catalyst. Different UV-curable liquid compositions were developed with naphthyl epoxy acrylates, different reactive diluents, and active amine monomer and 1-hydroxycyclohexylphenyl ketone (Irgacure 184) as a photoinitiator. Thin films were prepared by curing these composite solutions using a high pressure mercury lamp. The change of double bond absorption band was identified by Fourier transform infrared spectra during the UV-curing process. Gel content, water absorption, the pendulum hardness, mechanical properties (static and dynamic) and thermal characterizations of the UV-cured films were investigated. The characteristic C=C absorption of the unsaturated acrylic groups at 1635 cm-1 gradually disappeared with UV-cured time and was no longer detectable after irradiation for 10 s. The gel content and the pendulum hardness increased with increasing irradiation time, and these gradually turned to constant values with increasing the irradiation time as the degree of polymerization reached its saturation. With the increase of mono-functional reactive diluents butyl acrylate in the compositions, the gel content, the pendulum hardness and mechanical properties of UV-cured films decreased, except for the water absorption. It was found that the glass transition temperature and the storage modulus of MNEA compositions were higher than those of DNEA compositions by the dynamic mechanical measurements, and the glass transition temperature of MNEA compositions was 142°C. The thermogravimetric analysis of UV-cured films revealed that films prepared from naphthyl epoxy acrylates exhibited excellent thermal stability.

Some derivatives of anthraquinones containing acrylic moieties were synthesized and their structures elucidated by IR, UV, NMR and Mass spectra. Synthesized UV-curable vinylic monomers initiated polymerization of acrylates in the presence of UV-radiation. In terms of UV-absorbing, these compounds improved the light fastness of paints so that color changing, DE<1 achieved for waterbased red acrylic paint in the presence of hydroxyanthraquinone derivatives.

A series of multiple cross-linking ultraviolet (UV) curable waterborne polyurethane dispersions (UV-PUDs) were synthesized by modification of diglycidyl ether of bisphenol-A-based epoxy resin (E51) through ring-opening by 3-aminpropyltriethoxysilane (APTES). Initially, APTES-E51 was synthesized using APTES to open the epoxy groups of E51. Then, APTES-E51 was incorporated into the chains of polyurethane, and multiple cross-linking UV-PUDs were produced. The chemical structures were confirmed by the Fourier-transform infrared spectroscopy (FTIR) and the effect of the APTES-E51 content on the UV-PUDs properties was investigated. The average particle size of UV-PUDs was determined by dynamic light scattering (DLS). The result showed that the average particle size increased with increasing APTES-E51 content and the stability of the UV-PUD storage diminished when the content of APTES-E51 was 10.0%. After modification by APTES-E51, the water absorption of the UV-cured films decreased and the water contact angle (CA) increased significantly. Thermogravimetry analysis (TGA) of the UV-cured films illustrated that APTES-E51 modified UV-curable waterborne polyurethane could exhibit good thermal stability. In addition, mechanical property of the cured films showed that the incorporation of APTES-E51 also improved tensile strength of the cured films. We can obtain good storage stability, satisfied water resistance, and high thermal stability and tensile strength when the APTES-E51 content of the UV-PUD was 9.1%.

The current research work presents an attempt to develop an antimicrobial agent from the bioresource cardanol which can be embedded in the polymer matrix to develop a UV curable coating. The brominated cardanol (BC) was synthesized from liquid bromine (Br2) and cardanol followed by the reaction with triethylamine (TEA) to synthesize quaternary ammonium cardanol (AC). Further, the reaction with glycidyl methacrylate (GMA) gives a UV curable antimicrobial agent (AA). This AA was incorporated in the epoxy acrylate UV curable system in various proportions along with the photoinitiator and coated onto a wooden substrate. The Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopies and elemental analysis results revealed that the desired product has been formed. An antimicrobial test was performed with three types of microorganisms viz., bacteria, yeast, and fungi. The test results showed that the antimicrobial performance of the coatings was increased with the significant inhibition percentage values of 81. 59% for gram-positive bacteria (Staphylococcus aureus), 77. 12% for gram-negative bacteria (E. coli), and 73. 82% for yeast (Candida albicans). Also, there was a decrease in the growth% value of the fungi (Aspergillus niger) as the concentration of AA in the system was increased. The mechanical properties of all the coatings were similar. There was a decrease in the Tg as well as in the degradation temperature of the coating films as the concentration of AA was increased, but the char yield got increased, as well. The sample with 20 wt% of AA showed the maximum amount of char yield (11. 49%).