The tensile strength of injection-molded semi-crystalline resin (polyamide) matrix composites was improved to higher than the values predicted from the rule of mixture merely by adding 1.0–5.0 wt% of ramie fibers to the resin. This improvement was attributed to faster crystallization on the ramie fiber surface: so-called ‘transcrystalline’. The resin strength became equivalent to the composite strength after isothermal heat treatment. To elucidate this phenomenon, we observed transcrystallization on the fiber surface in a single fiber composite specimen as a function of heating time. Results show that, despite the short heating time, the transcrystalline layer occurs earlier than spherulites. However, with longer heating time, spherulite radius reached a level equivalent to the transcrystalline layer thickness, eventually exceeding it. Although the heat treatment applied for the low-fiber-content composites or the neat resin improves their strength, premature crystallization on the fiber surface can efficiently enhance the composites’ tensile strength without heat treatment.

For many years, 3D Printing technologies have created significant advancements in the fields of engineering and healthcare. 4D printing is also introduced, which is the advanced version of 3D printing. The process of 4D printing is when a printed 3D object becomes another structure due to the influence of outside energy inputs such as temperature, light, or other environmental stimuli. This technology uses the input of smart materials, which have the excellent capability of shape-changing. The self-assembly and programmable material technology aim to reimagine building, production, assembly of products, and performance. 4D printing is applied in various sectors such as engineering, medicine, and others. 4D printed proteins could be a great application. With this new dimension, 3D printed objects can change their shape by themselves over the influence of external stimuli, such as light, heat, electricity, magnetic field, etc. This paper discussed a brief about 4D printing technology. Various characteristics of 4D Printing for enhancing the manufacturing domain, its development, and applications are discussed diagrammatically. Conceptualised the Work Process Flow for 4D Additive Manufacturing and finally identified ten major roles of 4D printing in the manufacturing field. Although reversible 4D Printing itself is a fantastic development, it is innovative, and it employs durable and accurate reversal material during the shapeshift. It helps us create complicated structures that cannot be accomplished easily by traditional manufacturing technologies. It seems to be a game-changer in different industries by depending on natural factors instead of energy and changes the way to produce, develop, bundle, and ship goods entirely.

Additive manufacturing (AM) produces a complex shaped product from its data, layer by layer, with high precision and much less material wastage. As compared to the conventional manufacturing process, there are many positive environmental advantages of additive manufacturing technologies. Most importantly, there is less waste of raw material and the use of new and smart materials. It appears to concentrate on the output of a component on lesser material waste, energy usage, and machine emissions. There is a need to study the environmental sustainability of additive manufacturing technologies and their applications. As more businesses aim to strengthen their eco-footprint, sustainability in AM is gaining momentum. Visionary leaders of the industry are continually challenging their employees to find new ways to reduce waste, improving their workforce's manufacturing environment, and find innovative ways to use new materials to become more sustainable. The growth in value-added components, goods, and services has resulted from these initiatives. This paper discusses the significant benefit of additive manufacturing to create a sustainable production system. Finally, the paper identifies twelve major applications of AM for sustainability. Although additive manufacturing and technological dominance are being established with crucial industries, their sustainability advantages are visible in the current manufacturing scenario. The main goal is to identify the environmental benefits of additive manufacturing technologies over conventional manufacturing. Industries can now decide on suitable technologies to meet environmental goals.

This paper focuses on the development of polyvinylidene fluoride microfoam by implementing a chemical blowing agent through a continuous process. The objective was to investigate the effects caused by varying concentrations of chemical blowing agent, the use of a master batch as formulation variables, and variation of die temperature on the properties of polyvinylidene fluoride foam produced continuously. By using a 10% master batch formulation (contains 2% chemical blowing agent in final product), the cell density was increased while the cell size and foam density were decreased; the average cell size, cell density, and void fraction were found to be 50 μm, 7.7 × 10⁶ cells/cm³, and 33%, respectively. This is due to the increased cell density primarily due to the increased nucleation sites. At a lower chemical blowing agent, concentration of 1%, the die temperature was varied over a range of 125-145 °C, as this is approximately the melting point of the polyvinylidene fluoride. Decreasing the die temperature from 135 °C to 130 °C caused the cell density to increase and cell size to decrease, while void fraction decreased from 58% to 39%. This is due to the loss of melt strength upon increasing the temperature of the melt PVDF as it exits the die.

To explore a feasible strategy for improving the dielectric properties of carbon black (CB)/epoxy composites, CB@TiO₂ core-shell particles and CB-SiO₂ hybrid particles were prepared and incorporated into epoxy. The microstructures of CB, CB@TiO₂, and CB-SiO₂ particles, as well as the dielectric properties of their epoxy-based composites were investigated. The results showed that the composites containing CB-SiO₂ hybrid particles possessed a higher dielectric constant than the ones containing pristine CB. The dielectric constant of the composite with 20.0 vol% CB-SiO₂ reached 52.68 (1 kHz), which was ca. 4 times greater than that of the one containing 20.0 vol% pristine CB. Meanwhile, the composites containing CB@TiO₂ core-shell particles exhibited suppressed values of dielectric loss. The permittivity of the composite with 20.0 vol% CB@TiO₂ reached 19.52 (1 kHz), while its dielectric loss remained low (0.047 at 1 kHz). These results indicated that the dielectric properties of epoxy composites could be enhanced with the introduction of modified fillers.

The copolymerization of CO₂/propylene oxide (PO)/cyclohexene oxide (CHO) was carried out using a Zn-based heterogeneous catalyst, namely a supported multi-component zinc dicarboxylate. The monomer reactivity ratios of PO (r_PO) to CHO (r_CHO) were estimated using the Fineman-Ross and Kelen-Tudos graphical methods. The results showed that the r_PO values were significantly higher than the corresponding r_CHO values in all cases, indicating that the incorporation of CHO into the polymer was kinetically unfavorable. The influence of the reaction temperature and pressure on the monomer reactivity ratios was also discussed. It was found that raising either the reaction temperature or pressure led to an increase in r_CHO. In contrast, r_PO decreased upon increasing the reaction temperature, but exhibited a small fluctuation upon increasing the reaction pressure.