This work investigated low shrinkage curing techniques and characterization of unsaturated polyester (UPE-8340) and vinyl ester (VE-922) reinforced composite. The reinforced polymeric composite was composed using various amounts (0.1 vol.% to 0.5 vol.%) of methyl ethyl ketone peroxide (MEKP) and the proportion of UPE and VE (5 vol.%) was kept fixed throughout the study. The epoxy matrix was formed using a 3D printed acrylonitrile butadiene styrene (ABS) dumbbell shape mold and the specimen was cured in the presence of air and an inner gas (carbon dioxide) using a customized ambient closed chamber system. The influence of MEKP on UPE and VE reinforce composites was studied by investigating curing kinetics, shrinkage, tensile properties, contact angle, and thermal stability. The CO2-cured results show a significant lower shrinkage rate and higher tensile strength and flexural modulus of UPE and VE reinforced composite articles compared with air-cured reinforced composite. These macro-scale results correlate with the air-cured structure, an un-banded smooth surface was observed, and it was found that the lowest amount of MEKP revealed significant improvement in the contact angle of UPET and VE reinforced composites.

The oxygenated hydro diesel (OHD) is prepared from hydrogen peroxide (H2O2), acetone, and seaweed polysaccharide. A long-term study was carried out on the OHD fuel blend stability for about a year at various temperatures. The long-term stability shows very stable properties, no easy emulsion breaking, and a long storage period. The neat diesel and blend fuel performance test was conducted at various engine speeds, 1700–3100 RPM the diesel blend with 5 wt.% and 10 wt. % of H2O2 revealed the best fraction for reducing smoke and emissions. The blend contains 15 wt.% H2O2, revealing a significant reduction in exhaust temperature without considering the engine's performance. Moreover, the performance of the OHD also revealed an economizing rate, decreasing environmental pollution and prolonging the engine’s service life. The diesel engine performance and environmental evaluation leading to exhaust emissions characterization ($${\mathrm{CO}}_{\mathrm{X}}$$ CO X , $${\mathrm{SO}}_{\mathrm{X}}, {\mathrm{NO}}_{\mathrm{X}}$$ SO X , NO X , and others). Based on the results, the various concentrations of H2O2 are an effective method for reducing the emission of diesel engines. Decreased CO, SO2, unburned hydrocarbons, and NO2 were also observed as percentages of H2O2. Due to increased oxygen content, water content and cetane number, the number of unburned hydrocarbons from diesel fuel decreased with the addition of H2O2. Therefore, the OHD blend can significantly curtail the exhaust emission of conventional diesel fuel, which will help reduce the harmful greenhouse gas emissions from diesel fuel sources.