This study developed multifunctional polymer composites based on a PLA/PBAT (Polylactic Acid/ Poly(butylene adipate-co-terephthalate)) thermoplastic matrix reinforced with 20 wt.% corn husk fiber (CHF) and functionalized with conductive carbon black (CB) for smart consumer-electronics casings. Alkali treatment modified the lignocellulosic fiber surface, improving fiber–matrix interfacial adhesion and stress transfer within the polymer composite. Thermal characterization showed that the PLA cold-crystallization temperature decreased from 112.5°C for the unfilled blend to 104.6°C for treated-fiber composites and to 102.4°C at 6 wt.% CB, while PLA crystallinity increased from 17.2% to 32.1%. The optimized TCHF-CB4 polymer composite exhibited a tensile strength of 45.9 MPa, tensile modulus of 3.58 GPa, flexural strength of 72.6 MPa, and notched impact strength of 23.8 kJ m⁻². Its 5% mass-loss temperature was 307°C, confirming adequate thermal stability for melt processing. Electrical resistivity decreased from above 10¹⁰ Ω cm for TCHF20 to 3.4 × 10⁷, 7.8 × 10³, and 4.6 × 10¹ Ω cm at 2, 4, and 6 wt.% CB, respectively, indicating conductive-network percolation near 3–4 wt.% CB. TCHF-CB4 provided the best multifunctional polymer-composite balance, with a gauge factor of 4.8 and approximately 4.3% residual drift after cyclic loading. These results demonstrate a structurally reinforced, thermally processable, electrically responsive polymer composite suitable for integrated self-sensing casing applications. The combined action of treated fibers and conductive filler established reinforcement, crystallization, stiffness, conductivity, and sensing mechanisms.
Self-healing polymer composites become an attractive family of intelligent materials that are capable of autonomously repairing damage, which will enhance their durability, reliability and service life in extreme engineering applications. The materials are based on the principles of nature, using the nanofillers that are derived from biological systems to improve mechanical properties and self-healing capabilities by utilizing hierarchical structures and multifunctional interface interactions. The recent developments on the formulation of self-healing polymer composite with nanocellulose, graphene and graphene oxide, MXenes, engineered nanoclays, chitin nanofibers, catechol-functionalized nanoparticles, and other bioinspired nanofillers obtained from sustainable sources are reviewed. The intrinsic, extrinsic and vascular self-healing systems have been explored with a detailed discussion on the effect of these nanomaterials on crack arrest, stress transfer, interfaces adhesion, reversible covalent and supramolecular bonding, healing kinetics and mechanical reinforcement. In addition, the review compares different manufacturing methods, such as solution casting, melt blending, additive manufacturing, electrospinning, and in situ polymerization, and also discusses the impact of the manufacturing process on the dispersion of nanofiller, composite structure and healing properties. Recent advances are also explored in mechanical characterization, fracture toughness, fatigue resistance and thermal stability, electrical conductivity, and multifunction sensing capabilities to illustrate the wide range of possibilities of these advanced composites. The review also covers major issues associated with large scale commercialization such as nanofiller agglomeration, limited healing cycles, scalability, cost, recyclability, environmental stability for extended period, manufacturing complexity, etc. The next generation of autonomous structural materials is highlighted by emerging research trends of vitrimer chemistry, dynamic covalent networks, bio-derived sustainable polymers, machine learning-assisted materials design, digital manufacturing and artificial intelligence-driven optimization. In conclusion, the bioinspired nanofillers are a highly promising approach for the development of strong, multifunctional and sustainable self-healing polymer composites for application in various sectors including aerospace, automotive, civil engineering, marine, biomedical, and energy industries, and also the future research directions required for successful industrial scale implementation of the materials.
The growing demand for sustainable engineering materials has accelerated the development of biodegradable polymer composites capable of combining structural performance with intelligent lifecycle management. In this study, a smart biodegradable agro-waste polymer composite reinforced with rice husk and sugarcane bagasse fibers were developed using a polylactic acid (PLA) matrix integrated with an embedded passive Near Field Communication (NFC) tag for digital traceability and circular economy applications. The composite containing 80 wt.% PLA, 15 wt.% hybrid agro-waste reinforcement and 5 wt.% PLA-g-MA compatibilizer was fabricated through twin-screw extrusion followed by compression molding. SEM analysis confirmed uniform fiber dispersion and strong fiber–matrix bonding. Tensile strength increased from 58 MPa to 74 MPa, while flexural strength improved from 82 MPa to 106 MPa, representing enhancements of 27.6% and 29.3%, respectively. Thermogravimetric analysis demonstrated improved thermal stability through delayed degradation and higher residual char formation. Controlled composting showed progressive biodegradation, with the hybrid NFC-integrated composite achieving approximately 47.5% weight loss after 56 days compared with 19% for neat PLA. The embedded passive NFC tag maintained reliable functionality without affecting structural integrity or biodegradation behavior. The developed smart biodegradable composite successfully combines enhanced mechanical performance, thermal stability, controlled biodegradability and digital lifecycle tracking, demonstrating strong potential for sustainable packaging, agricultural products, consumer goods and other environmentally responsible circular economy applications while supporting efficient product identification, recycling, resource recovery initiatives globally.
Pectin is a versatile heteropolysaccharide that is widely used in the food, pharmaceutical, and biomedical industries because of its gelling, stabilizing, and emulsifying properties. This review discusses the extraction of pectin from agro-waste peels of Malabar tamarind (Garcinia cambogia) and Indian wild lime (Citrus indica) using conventional acid hydrolysis under optimized conditions: pH 1.5–2.0, 85–90°C, and 90 minutes. The process resulted in 22.5% and 27.8% pectin yields, respectively, verified through triplicate experiments. Structural characterization with Fourier Transform Infrared (FTIR) spectroscopy confirmed characteristic functional groups, such as O–H stretching (~3350 cm⁻¹), esterified C=O (~1740 cm⁻¹), and COO⁻ vibrations (~1635 cm⁻¹). Size Exclusion Chromatography (SEC) showed molecular weights of 85–95 kDa with polydispersity indices of 1.35–1.45, comparable to commercial citrus pectin. A comparative evaluation suggests these local fruit wastes are competitive sources of pectin, offering sustainability benefits through the use of agro-waste and promoting a circular economy. Future plans include using ultrasound-assisted and enzymatic extraction methods to improve yield and process sustainability.
Electrically conductive polymer composites have emerged as promising multifunctional materials for lightweight antenna housings by integrating structural strength, electrical conductivity, thermal stability, and electromagnetic interference shielding. In this study, micro-aluminum reinforced Acrylonitrile Butadiene Styrene (ABS) polymer composites were fabricated using twin-screw melt compounding followed by compression molding for IoT-enabled lightweight antenna housing applications. The influence of micro-aluminum loading on microstructure, mechanical performance, electrical conductivity, EMI shielding, thermal stability, and wireless monitoring was systematically investigated. Scanning electron microscopy revealed uniform particle dispersion and strong polymer-particle interfacial bonding, promoting efficient stress transfer and continuous conductive pathways throughout the polymer matrix. Mechanical characterization demonstrated progressive improvements in tensile strength and flexural strength with increasing filler content. The optimized ABS-Al20 composite achieved an electrical conductivity of 3.85 × 10⁴ S/m and an EMI shielding effectiveness of approximately 38 dB, indicating excellent multifunctional performance. Thermogravimetric analysis confirmed enhanced thermal resistance through the barrier effect of uniformly dispersed aluminum particles. An ESP32-based IoT monitoring system enabled real-time acquisition of temperature, humidity, and vibration data with wireless cloud transmission for continuous structural health monitoring. The developed conductive polymer composite successfully combines lightweight construction, mechanical robustness, electrical functionality, EMI shielding, thermal durability, and intelligent monitoring within a single material platform. These findings demonstrate significant potential for next-generation communication infrastructure, automotive electronics, aerospace systems, smart wireless devices, and advanced IoT applications requiring durable, lightweight, electrically conductive polymer composite materials supporting sustainable high-performance antenna housings with improved reliability, durability, electromagnetic compatibility, and long-term service performance in demanding environments.
