The interest in designing new environmentally friendly materials has led to the development of biodegradable foams as a potential substitute to most currently used fossil fuel–derived polymer foams. Despite the possibility of developing biodegradable and environmentally friendly polymer foams, the challenge of foaming biopolymers still persists as they have very low melt strength and viscosity as well as low crystallisation kinetics. Studies have shown that the incorporation of cellulose nanostructure (CN) particles into biopolymers can enhance the foamability of these materials. In addition, the final properties and performance of the foamed products can be improved with the addition of these nanoparticles. They not only aid in foamability but also act as nucleating agents by controlling the morphological properties of the foamed material. Here, we provide a critical and accessible overview of the influence of CN particles on the properties of biodegradable foams; in particular, their rheological, thermal, mechanical, and flammability and thermal insulating properties and biodegradability.

This study investigated the effect of the Joncryl concentration on the properties of polylactide/poly(ε-caprolactone) (PLA/PCL) and PLA/poly(ethylene glycol) (PEG) blends. The addition of Joncryl influenced the properties of both PLA-based blends. In the blend of PLA/PCL blends, the addition of Joncryl reduced the size of PCL droplets, which implies the compatibility of the two phases, while PLA/PEG blends showed a co-continuous type of morphology at 0.1% and 0.3 wt.% of Joncryl loading. The crystallinity of PCL and PEG was studied on both PLA/PCL and PLA/PEG blend systems. In both scenarios, the crystallinity of the blends decreased upon the addition of Joncryl. Thermal stabilities were shown to depend on the addition of Joncryl. The toughness increased when 0.5 wt.% of Joncryl was added to both systems. However, the stiffness of PLA/PCL decreased, while the stiffness of PLA/PEG increased with the increasing concentration of Joncryl. This study provides new insight into the effect of chain extenders on the compatibility of PLA-based blends.

Poly (ε-caprolactone) (PCL)/hydroxyapatite (HAP) composites represent a novel material with desired properties for various applications. In this work, PCL/HAP composites at low loadings were developed through melt-extrusion processing. The effects of HAP loading on viscoelastic, thermal, structural, and mechanical properties of PCL were examined. The morphological analysis revealed better dispersion of HAP at low loadings, while aggregation was noticed at high concentrations. The complex viscosity of the prepared composites increased with increasing concentration of HAP. In addition, a significant decrease in crystallinity was observed upon increase in HAP loading. However, the elongation at break increased with increasing the concentration of HAP, probably due to a decrease in crystallinity. The onset thermal degradation temperature of PCL was enhanced at low concentrations of HAP, whereas a decrease was observed at high loading. Overall, different degrees of HAP dispersion resulted into specific property improvement.

Herein, biodegradable composites of poly(ɛ‐caprolactone) (PCL)/hydroxyapatite (HAP)/urea, with potential application in agriculture, were developed. The concentration of HAP was fixed at 3 wt%, while urea concentration varied from 1 to 9 wt%. The effects of urea loading on the morphological, flow properties, and soil biodegradation of PCL/HAP composites were investigated. The morphological characterization showed well dispersion of HAP and urea particles in the PCL matrix. A decrease in viscosity of PCL was noticed upon the inclusion of urea at 1 wt%, indicating the plasticization effects of urea, whereas an increase in viscosity was observed with increasing the concentration. The morphological analysis after soil burial showed microbial adherence on the surface of the samples. In addition, the formation of cracks, holes, and uneven surfaces were noticed. The atomic force microscope analysis showed an increase in surface roughness due to surface degradation of the samples. On the other hand, two‐step degradation curves were noticed in the samples before soil degradation. In contrast, a single step degradation curve was observed after degradation, indicating the leaching of urea from the samples. Overall, PCL/HAP/urea composites with enhanced degradation rates were developed, and they can be applied in agriculture, where the materials can be buried after their end‐use.

The technology of 4DP utilizes shape memory materials (SMMs). Among the SMMs, SMP is the material that has potential and is ideal for this technology. However, due to their restrictions, fillers are incorporated to produce a novel shape memory polymer composite (SMPC). The objective of the present work was to investigate how the modification of PLA via the incorporation of boehmite alumina and thermochromic dye, and the use of 3DP on polyester fabric to make smart material textiles (SMT), influenced the shape-memory properties of printed objects. SMPCs with 3 wt% BA particles were prepared by means of the fused deposition modelling (FDM) process, with heat used as an actuation. It was demonstrated that sample thickness and the method of PLA modification affected the shape recovery of 3D-printed objects. All neat PLA samples recovered their angle fully for all thicknesses, while modified PLA incorporated with BA particles and dye recovered its initial angle fully at 1 mm thickness and showed less recovery for 1.5- and 2 mm-thicknesses. The 1 mm-thick sample was then chosen for printing onto the textile material for all samples. When printed onto the fabric, the neat PLA and SMPCs recovered their initial shapes fully, while samples with the dye added into the PLA and SMPC did not recover their initial shape fully due to the presence of the dye, which hindered the movement of the polymer chains. SEM revealed good layer bonding for the SMPCs compared to the neat PLA, which led to improved mechanical properties. The thermal stability of PLA was improved by the BA particles; furthermore, the dye and BA particles nucleated the crystallization of PLA, resulting in an enhanced storage modulus. Overall, a biodegradable 3D-printed object of 1 mm in thickness with improved thermal and mechanical properties was produced, with and without the use of the textile.

Acrylonitrile butadiene styrene (ABS) is a widely used polymer in the automotive, electronics, and household appliance industries. Despite its extensive use, ABS suffers from low thermal stability, flammability, poor UV stability, and limited recyclability. Hence, it requires blending with low‐cost polymers such as linear low‐density polyethylene (LLDPE), although this type of blend is immiscible. In this study, the role of multi‐walled carbon nanotubes (MWCNTs) as morphology‐directing agents on the rheological and morphological properties, and thermal stability of melt‐mixed (ABS)/LLDPE (80/20) blends was studied. Morphological developments were examined by rheological and microscopic techniques. The neat blend exhibited heterogeneous dispersion of LLDPE droplets and elongated threads in a continuous phase. At low MWCNTs loadings, the matrix‐dispersed morphology was retained. However, a transition from matrix‐dispersed to co‐continuous morphology was observed when increasing the concentration of MWCNTs. This transition was corroborated by rheological and microscopy analysis, and infrared microscopy. Moreover, the morphological analysis revealed the localization of MWCNTs at the interface at high loadings. The thermal stability of the blend increased in the presence of MWCNTs, implying a delayed thermal degradation process. The observed findings suggest that the developed nanocomposites are a promising alternative material for applications traditionally dominated by neat ABS.