Recently, polymer science and engineering research has shifted toward the development of environmentally benign polymers to reduce the impact of plastic leakage on the ecosystems. Stringent regulations and concerns regarding conventional polymers are the main driving forces for the development of renewable, biodegradable, sustainable, and environmentally benign materials. Although biopolymers can alleviate plastic‐related pollution, several factors dictate the utilization of biopolymers. Herein, an overview of the potential and limitations of synthetic biopolymers and their composites in the context of environmentally benign materials for a sustainable future are presented. The synthetic biopolymer market, technical advancements for different applications, lifecycle analysis, and biodegradability are covered. The current trends, challenges, and opportunities for bioplastic recycling are also discussed. In summary, this review is expected to provide guidelines for future development related to synthetic biopolymer‐based sustainable polymeric materials suitable for various applications.
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.
The article reviews the different methods of which, phytic acid (PA) can be employed as a flame retardant (FR) filler for different polymeric materials. The methods are critically discussed, based on the available literature and patents. Depending on the method used and the addition of FRs into a PA flame retarded system, different flame retarding modes of action and fire resistance performances are attained. The mechanism of action for PA‐based system remains similar to those observed in other phosphorus‐based FRs, namely, condensed and gas‐phase mechanisms.
This work investigates the effect of cellulose nanocrystal (CN) loading on the properties of polylactide/poly(ε-caprolactone) (PLA/PCL) (70/30) blend processed in a twin-screw extruder as a potential material that can be utilized in various applications where biodegradation is highly desired. The morphological analysis revealed a reduction in droplet size of dispersed PCL phase upon addition of CN at low concentrations (1 and 2 wt %) with maximum reduction at 2 wt % which led to maximum improvement in mechanical properties. The reinforcing effect of CN in increasing the DMA storage modulus of the prepared systems was noticed when CN concentration was increased. Further, CN enhanced the crystallization of PCL, whereas the cold crystallization of PLA remained the same with CN addition. Both melt strength and viscosity of PLA improved with the incorporation of PCL and CN. In general, a green composite material with improved properties was successfully prepared using an environmentally friendly filler material.
Carbon nanofillers containing biodegradable polymer composites have become an emerging frontier in materials science and engineering because of their potential as environmentally friendly materials in multiple applications, from load-bearing to advanced packaging to biomedical applications. Herein, we present the effect of processing parameters on the final morphology and the resulting properties of the biodegradable polymer composites containing carbon nanotubes (CNTs) or carbon nanofibers (CNFs). Various strategies can be employed to develop such composites; however, the type of morphology, which results during processing, significantly affects the final properties of the obtained composites. Therefore, various processing strategies such as meltblending, additive manufacturing, and electrospinning are critically reviewed, together with the potential applications in load-bearing, tissue engineering, electromagnetic shielding, gas sensing, and packaging. Finally, we discuss the existing challenges and future directions in designing CNTs/CNFs containing biodegradable polymer composites with desired properties.
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.
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.
This study examines the influence of cellulose nanocrystal (CN) particles on the morphological, thermal, and thermo-mechanical properties of polylactide (PLA)/poly [(butylene succinate)-co-adipate] (PBSA) blend foams prepared by casting and particulate leaching method using fructose as porogen particles. The morphological analysis showed an interconnected open-cell structure, with porosity above 80%. The crystallinity of the prepared foams was disrupted by the inclusion of CN particles as observed from XRD analyses, which showed a decrease in PLA crystal peak intensity. With regards to neat blend foam, the onset thermal degradation increased with the addition of CN particles, which also increased the thermal stability at 50% weight loss. Furthermore, CN acted as a reinforcing agent in improving the stiffness of the prepared blend foam. Overall, completely environmentally friendly foams were successfully prepared, as a potential material that can replace the current existing foam materials that pose many environmental concerns. However, there is a need to develop an environmentally friendly processing technique.
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