Simultaneous wettability and stiffness control of UV-curing vegetable oil resin composites by lignocellulosic components

Acrylic resins have various applications, which range from coatings to 3D printing, among others. Following green chemistry and environmental preservation trends, the demand for bio-based acrylic resins is growing. Vegetable oil-based resins have arisen to meet the present challenge. However, the performance and tuning of sustainable resin properties still need improvement. Hence, we undertook this study to research tuneable and durable vegetable oil-based UV-curing composite resins. This work reports on vegetable oil-based resin loaded with lignocellulosic components of cellulose nanocrystals (CNC), cellulose nanofibres (CNF), hemicellulose (HC), and lignin (LN). The effects of lignocellulosic components on thermal stability, thermomechanical properties, transparency, surface morphology, and wettability were evaluated in detail. In addition, the interaction of lignocellulosic components with the polymer matrix and interface was thoroughly investigated. The intense interaction between lignocellulosic components and the polymer matrix helps to form a strong interface and creates a polymer composite with enhanced thermomechanical properties. The composite surface morphology and wettability can be tuned depending on the lignocellulosic component, i.e., with the addition of HC, CNC, and CNF. Hydrophilic affinity is improved and water wetting angles as low as 8 can be achieved, but with LN a value of 96 degrees was observed, a slight increase in hydrophobicity compared to the vegetable oil (VO) matrix value of 90 degrees. Adding HC and CNC reduced transparency at 500 nm by 14 and 16%, while adding LN and CNF by 18 and 25%, respectively. Fourier-transform infrared spectroscopy revealed strong interfacial interactions through the hydrogen bonding between CNC, CNF, HC, and the VO polymer. This work will shed light on the lignocellulosic components' future role in UV-curing resin applications. It also broadens lignocellulosic particles' application as reinforcing additives for UV-light sensitive polymeric resins.

Automated summary

This study investigates the tunable and durable vegetable oil-based UV-curing composite resins. By adding lignocellulosic components such as cellulose nanocrystals, cellulose nanofibres, hemicellulose, and lignin, the thermal stability, thermomechanical properties, transparency, surface morphology, and wettability of the resin can be improved. Strong interaction between the lignocellulosic components and the polymer matrix enhances the thermomechanical properties of the composite. The surface morphology and wettability of the composite can be tuned by the addition of different lignocellulosic components. The effects of different components on the transparency of the resin are also evaluated.