Novel epoxidized hemp oil-based biocomposites containing jute fibre reinforcement were produced at the Centre of Excellence in Engineered Fibre Composites (CEEFC) owing to the need to develop new types of biobased materials. Mechanical properties (tensile, flexural, Charpy impact and interlaminar shear), thermo-mechanical properties (glass transition temperature, storage modulus and crosslink density) and moisture-absorption properties (saturation moisture level and diffusion coefficient) were investigated and compared with samples containing commercially produced epoxidized soybean oil and a synthetic bisphenol A diglycidyl ether-based epoxy control, R246TX cured with a blend of triethylenetetramine and isophorone diamine. Scanning electron microscopy was also performed to investigate the fibre–matrix interface. Epoxidized hemp oil-based samples were found to have marginally superior mechanical, dynamic mechanical and similar water-absorption properties in comparison to samples made with epoxidized soybean oil bioresin; however, both sample types were limited to bioresin concentrations below 30%. Synthetic epoxy-based samples exhibited the highest mechanical, dynamic mechanical and lowest water-absorption properties of all investigated samples. This study has also determined that epoxidized hemp oil-based bioresins when applied to jute fibre-reinforced biocomposites can compete with commercially produced epoxidized soybean oil in biocomposite applications.

In this work, the cure kinetics of a novel acrylated epoxidized hemp oil (AEHO)-based bioresin was investigated for the first time by differential scanning calorimetry (DSC) using both isothermal and nonisothermal conditions. This new bioresin was synthesized by the acrylation of a previously epoxidized hemp oil (EHO) bioresin. The curing of the AEHO bioresin showed an autocatalytic behavior with the vitrification phenomenon preventing the conversion reaching unity for all the temperatures studied. It was found that the curing behavior can be modeled with high accuracy using a modified Kamal autocatalytic model that takes into account the vitrification phenomenon. Dynamic activation energies were determined from the Kissinger and Ozawa-Flynn-Wall methods, resulting in 58.87 and 62.02 kJmol À1 , respectively. In addition, activation energies associated with the autocatalytic model constants, k 1 and k 2 , were established to be equal to 58.94 and 45.32 kJmol À1 , respectively.

A novel epoxidized hemp oil (EHO) based bioresin was synthesized by epoxidation in situ with peroxyacetic acid. In this research the cure kinetics of an EHO based bioresin system cured with triethylenetetramine (TETA) was studied by differential scanning calorimetry using both isothermal and nonisothermal data. The results show that the curing behavior can be modeled with a modified Kamal autocatalytic model that accounts for a shift to a diffusion-controlled reaction postvitrification. The total order of the reaction was found to decrease with an increase in temperature from $ 5.2 at 110 C to $ 2.4 at 120 C. Dynamic activation energies were determined from the Kissinger (51.8 kJ/ mol) and Ozawa-Flynn-Wall (56.3 kJ/mol) methods. Activation energies determined from the autocatalytic method were 139.5 kJ/mol and À80.5 kJ/mol. The observed negative activation energy is thought to be due to an unidentified competitive reaction that gives rise to the appearance of k 2 decreasing with increasing temperature. The agreement of fit of the model predictions with experimental values was satisfactory for all temperatures. V C 2011 Wiley Periodicals, Inc. J Appl Polym Sci 122: [444][445][446][447][448][449][450][451] 2011

In this study, novel acrylated epoxidized hemp oil bioresin was used in the manufacturing of jute fibre reinforced biocomposites. The 100% biocomposite laminates were characterised in terms of mechanical properties (tensile, flexural, Charpy impact and interlaminar shear), thermo-mechanical properties (glass transition temperature, storage modulus and crosslink density) and water absorption properties (saturation moisture level and diffusion coefficient). Comparisons with the equivalent synthetic vinylester resin based jute fibre reinforced biocomposite panels were performed. Scanning electron microscopic analysis confirmed panel samples containing acrylated epoxidized hemp oil to display improved fibre–matrix interfacial adhesion compared with the vinylester resin based samples. Furthermore in terms of mechanical properties acrylated epoxidized hemp oil based biocomposites compared favourably with those manufactured from vinylester resin synthetic resin. Dynamic mechanical analysis found acrylated epoxidized hemp oil based biocomposites to have lower glass transition temperature, storage modulus and crosslink density than vinylester resin based samples. Increasing acrylated epoxidized hemp oil content resulted in a marginal increase in saturation moisture content and diffusion coefficient.

The cure kinetics of two epoxidized hemp oil (EHO) based bioresins were studied and compared under both dynamic and isothermal conditions using differential scanning calorimetry (DSC). Neat triethylenetetramine (TETA) for the first system and a combination of isophorone diamine (IPD) and TETA for the second system were used as the hardeners for the two EHO‐based bioresins. Lower total heats of reaction and an approximate 10% decrease in activation energies were observed for the IPD/TETA system. Maximum conversions of the TETA/IPD system were consistently higher than those of the TETA system throughout the entire temperature range suggesting enhanced curing characteristics. Kissinger and Ozawa–Flynn–Wall models were used to determine activation energies from dynamic DSC data. Both bioresin systems were found to display autocatalytic behavior with the TETA/IPD system showing high nth order influence. Kamal's autocatalytic isothermal model, modified to account for diffusion postvitrification was found to satisfactorily describe the cure behavior of both bioresin systems. Overall, the addition of IPD was found to increase the curing rate of the EHO bioresin systems. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012