Sustainable polypropylene composites reinforced with Citrus limetta peel: Effects on mechanical performance and crystallinity Alok Misra, Hitesh Sharma, T Sudhakar Proceedings of the Institution of Mechanical Engineers Part L Journal of Materials Design and Applications, 2026 This study investigates the effect of Citrus limetta peel (CLP) bio-filler on the moisture diffusion behavior, structural characteristics, and mechanical performance of polypropylene (PP) composites. The composites were prepared using CLP particles (100–250 μm) at filler loadings of 10–30 wt% through an extrusion–compression molding process. Water absorption behavior was evaluated according to ASTM D570 at ∼23 °C, and diffusion was analyzed using Fickian theory. The results show that equilibrium moisture uptake increased from 2.01% for virgin PP to 7.03% for PP–30CLP due to the hydrophilic nature of the lignocellulosic filler. Correspondingly, the diffusion coefficient increased from 1.8 × 10 − 8 cm 2 /s to 4.8 × 10 − 8 cm 2 /s with increasing filler content. Mechanical testing revealed that tensile strength decreased from 26.99 MPa to 17.80 MPa, while tensile modulus increased from 425 MPa to 446 MPa at 10 wt% CLP, indicating improved stiffness at moderate loading. Similarly, flexural strength decreased from 43.31 MPa to 31.94 MPa, whereas flexural modulus increased to 1569 MPa at 10 wt% before slightly decreasing at higher loadings. Statistical analysis using one-way ANOVA confirmed that the changes in mechanical properties are significant (p < 0.05). X-ray diffraction analysis indicated a reduction in crystallinity due to restricted polymer chain mobility, while scanning electron microscopy revealed filler agglomeration and increased porosity at higher filler contents. Overall, CLP waste demonstrates potential as a sustainable bio-filler for PP composites, although optimization of filler loading is required to balance mechanical performance and moisture resistance.
The Mechanical Properties of Pine Needle Fiber-Reinforced Polymer Composites Under Different Environments Pawan Kumar Rakesh, Kassahun Gashu Melese, Somit Gairola, Hitesh Sharma, S. Rajkumar Engineering Reports, 2025 This study investigated the mechanical and tribological properties of NaOH‐treated pine needle fiber‐reinforced epoxy composites (PNFREC) under various environmental conditions, including exposure to water, kerosene, and petrol. Pine needles from Himalayan forests were treated with a 10% NaOH solution to enhance their hydrophobicity and fiber‐matrix adhesion. Composites were fabricated using a hand lay‐up method with 30 wt. % bidirectional pine needle fiber mats and an epoxy matrix (LY‐556 resin and HY‐951 hardener). Water absorption tests revealed an average uptake of 3.22% ± 3.47% after 168 h, which is significantly lower than that of untreated composites. Mechanical testing under ambient conditions showed a 28.6% increase in tensile strength (45 MPa), a 27.3% improvement in flexural strength (70 MPa), a 66.7% enhancement in impact strength (25 kJ/m2), and a 9.3% increase in Shore hardness (82 Shore D) compared to neat epoxy. Water exposure caused the most significant degradation, with a 15.6% reduction in tensile strength, a 17.1% decrease in flexural strength, a 20% drop in impact strength, and a 7.3% decline in Shore hardness, owing to interfacial weakening and matrix plasticization. Kerosene and petrol exposure led to minor reductions in mechanical properties due to limited matrix swelling and interfacial degradation. Tribological analysis revealed a 28.6% reduction in the specific wear rate (2.5 × 10−5 mm3/N·m) under ambient conditions, which was attributed to the protective effect of the pine needle fibers. Water exposure increased the wear rate by 60% (4.0 × 10−5 mm3/N·m) due to abrasive wear, whereas kerosene and petrol reduced the wear rate by 28% and 12%, respectively, through lubrication. Scanning electron microscopy (SEM) analysis correlated the mechanical and tribological performance with the microstructural features, revealing fiber‐matrix debonding, matrix cracking, and wear mechanisms. The results highlight the potential of PNFREC for sustainable structural applications, particularly in hydrocarbon environments, while addressing the challenges of moisture‐induced degradation.
Preliminary studies into polypropylene composites reinforced with fruit waste biomass: a choice towards sustainability Hitesh Sharma, Sandeep Gairola, Joy Prakash Misra, Inderdeep Singh Physica Scripta, 2025 The development of polypropylene (PP) composites filled with a biomass from fruit waste, citrus limetta peel (CLP) fillers is explored in the current study. A polymer matrix consisting of neat polypropylene was filled with 10, 20, and 30% weight percentage (w/w) of CLP. The composite specimens were produced by extrusion followed by injection moulding. In addition to thermal and morphological evaluations, the mechanical properties are determined, including tensile and flexural (both strength and modulus). The primary results demonstrate that, for a 10 weight percent filler content, the inclusion of CLP filler raised the tensile and flexural modulus of the neat PP composites by 20.23% and 14.33%, respectively. All of the composites were found to be thermally stable up to 220 °C through thermal investigation. The burning rate increased with the incorporation of fillers whereas, the dripping effect gets reduced. Filler agglomeration, filler pull out, and poor adherence with increased CLP filler content were observed using scanning electron microscopy. The developed composites have got tremendous potential to be utilized in non-structural applications. The consequences of plastic burden on the environment can also be reduced.
Epoxy composite dust reinforced novel polypropylene composites: An eco-friendly approach toward sustainable resource management Hitesh Sharma, Sandeep Gairola, Joy Prakash Misra, Inderdeep Singh Polymer Engineering and Science, 2024 This study presents an innovative technique for recycling leftover epoxy composites reinforced with natural fillers. The waste epoxy composites were successfully ground into a 75–150 μm fine powder. With the aid of extrusion injection molding, this powder was subsequently utilized to create polypropylene matrix‐based polymer composites with variable filler loadings ranging from 10% to 30%. The mechanical, thermal, thermomechanical, and morphological properties of the developed composites were assessed. The greatest tensile strength of the polypropylene composites produced with 10% filler loading was found to be 24.15 MPa. The addition of epoxy composite filler increased the thermal stability. During morphological investigations, it was discovered that pits, voids, and filler agglomerations predominated the fractured surface of the developed composites. Overall, it can be concluded that there is a lot of promise for value‐added recycling of thermosetting resin‐based composites using this low‐cost, high‐efficiency, and ecologically benign process, which would lessen the environmental impact of plastic.Highlights Novel polypropylene composites using epoxy composite dust was developed. Mechanical, thermal, thermomechanical, and morphological studies were performed. Toys, tableware, mementos, and furniture can be the potential applications. The developed composites can reduce plastic load on the environment.
Machine learning approaches for drilling GFRP laminate: A study for thrust force and torque-induced damage Hitesh Sharma, Pawan Kumar Rakesh, Inderdeep Singh Forming and Machining of Polymers Ceramics and Composites, 2024 Lightweight, strong, and dimensionally accurate by nature, glass fibre–reinforced plastics offer a weather-resistant finish and may be produced in an almost infinite number of colours and surface textures. The goal of this study is to apply a machine learning technique to predict how fibre-reinforced plastic laminates will fare when subjected to machining (drilling). The user is often caught in a bind when trying to optimise the drilling process by choosing appropriate input parameters. The artificial neural network model that was developed for the purpose of this study supplies the standards for any given set of input parameters like the delamination factor, the thrust force, and the torque. In this way, the user may see what kind of wear and tear the drill hole would be able to sustain for different values of parameters, such as the feed rate, the geometry of the drill, the drill diameter, and the cutting speed. The designed user interface can also be used to evaluate the impact of varying input parameters on drilling-induced damage, allowing for the identification of optimal settings that minimise damage and maximise efficiency.
Drilling characteristics of fibre-reinforced polylactic acid composites: A study on Himalayacalamus Falconeri fibre-based composites Mayank Pokhriyal, Pawan Kumar Rakesh, Rajesh Kumar, Shaurya Bhatt, Vivek Bahuguna, Hitesh Sharma Forming and Machining of Polymers Ceramics and Composites, 2024 Himalayacalamus falconeri tree is extensively available in the hilly forests of Uttarakhand. H. falconeri culms are collected from trees and fibre was extracted from H. falconeri culms by water retting method. Extracted H. falconeri fibre is dried in an electric oven at the temperature of 90°C to remove moisture/water from the fibre surface. Dried H. falconeri fibre was reinforced into polylactic acid to prepare composite laminates via an injection moulding machine. The fibre concentration was kept at 15% in the polylactic acid. The drilling parameters (two different drill point geometry, namely, twist drill and JO drill; cutting speed – 560 rpm and feed rate – 0.3 and 0.19 mm/rev) were selected to study the effect of parameters on the drilling forces. The forces were recorded via a four-component dynamometer (9272) during the process on polylactic-based composites.
Influence of the fruit waste fillers on the thermal, mechanical, and morphological properties of flax/epoxy composites Sudhir Chaudhary, Sandeep Gairola, Hitesh Sharma Proceedings of the Institution of Mechanical Engineers Part L Journal of Materials Design and Applications, 2024 In the present research endeavor, the waste shells of pistachio and walnut have been used in the form of fillers to develop hybrid flax epoxy composites. The effect of hybridization on the developed composites was studied in terms of thermal, mechanical, and morphological properties. The properties like tensile strength, tensile modulus, flexural strength, flexural modulus, impact strength, and shore hardness were evaluated to ascertain the mechanical behavior. The thermogravimetric analysis of the composites was also performed in order to determine the thermal stability of the developed composites. The results revealed that pistachio shell filler-based flax/epoxy composites showed improved tensile strength and tensile modulus by over 73.26% and 42.53% in comparison to the control specimen. The walnut shell filler-based flax/epoxy composites also exhibited improved tensile strength and tensile modulus by 66.41% and 17.1% compared to the control specimen. Whereas, the hybrid filler-based flax/epoxy composites were found to be thermally more stable. The fractography of the developed composites was also studied using scanning electron microscope which revealed good filler distribution in the epoxy matrix.
An initial investigation to explore the feasibility of fruit waste fillers for developing sustainable thermoplastic composites Hitesh Sharma, Inderdeep Singh, Joy Prakash Misra Proceedings of the Institution of Mechanical Engineers Part L Journal of Materials Design and Applications, 2023 The current research work is aimed to study the potential of citrus limetta peel (fruit waste) as a novel filler in thermoplastic composites. Three different sizes of citrus limetta peel (CLP) fillers were processed and their thermal characteristics such as thermo-gravimetric analysis (TGA) and derivative thermogravimetry (DTG) were evaluated to investigate the degradation behaviour of each filler size under temperature. FTIR analysis of the CLP was also done to study the structure of inter- and intra-molecular hydrogen bonding in cellulose. The morphological study was also performed on both the outer surface as well as the inner surface of CLP in order to examine the surface characteristics. Based on the thermal characteristics of CLP filler, CLP-filled thermoplastic (poly-lactic acid) composite samples (by 20% weight percentage) were successfully fabricated using the injection moulding technique and were evaluated for their thermal, mechanical, and microstructural behaviour. It has been established that CLP fillers are amenable to processing using closed-mould processes such as injection moulding with fabricated products finding possible application in non-structural products, preferably in the particle board industry. As per the feasibility analysis, CLP fillers have the potential to be commercially exploited for product development.
Introduction to Green Composites Hitesh Sharma, Ujendra Kumar Komal, Inderdeep Singh, Joy Prakash Misra, Pawan Kumar Rakesh Materials Horizons from Nature to Nanomaterials, 2019
Artificial intelligence based tool for predicting of damage during drilling of FRP’s Iccm International Conferences on Composite Materials, 2017
RECENT SCHOLAR PUBLICATIONS
Sustainable polypropylene composites reinforced with Citrus limetta peel: Effects on mechanical performance and crystallinity A Misra, H Sharma, T Sudhakar Proceedings of the Institution of Mechanical Engineers, Part L: Journal of … , 2026 2026
Impact of Crude Oil Residue Fillers on the Mechanical, Thermal, and Flammable Properties of Hybrid Kenaf/Epoxy Composites S Kumar, H Sharma, A Kumar, A Singh Waste and Biomass Valorization, 1-14 , 2025 2025
The Mechanical Properties of Pine Needle Fiber‐Reinforced Polymer Composites Under Different Environments PK Rakesh, KG Melese, S Gairola, H Sharma, S Rajkumar Engineering Reports 7 (10), e70376 , 2025 2025 Citations: 1
Physio-mechanical and thermal behavior of kenaf ( Hibiscus cannabinus L.) fiber-reinforced epoxy composites: effect of eco-friendly treatment P Negi, P Bhatt, H Sharma, GS Brar Biomass Conversion and Biorefinery 15 (10), 15427-15436 , 2025 2025 Citations: 6
Preliminary studies into polypropylene composites reinforced with fruit waste biomass: A choice towards sustainability H Sharma, S Gairola, JP Misra, I Singh Physica Scripta , 2024 2024 Citations: 2
Epoxy composite dust reinforced novel polypropylene composites: An eco‐friendly approach toward sustainable resource management H Sharma, S Gairola, JP Misra, I Singh Polymer Engineering & Science , 2024 2024 Citations: 4
Drilling Characteristics of Fibre-reinforced Polylactic Acid Composites: A Study on Himalayacalamus falconeri Fibre-based Composites M Pokhriyal, PK Rakesh, R Kumar, S Bhatt, V Bahuguna, H Sharma Forming and Machining of Polymers, Ceramics, and Composites, 124-133 , 2024 2024
Machine Learning Approaches for Drilling GFRP Laminate: A Study for Thrust Force and Torque-induced Damage H Sharma, PK Rakesh, I Singh Forming and Machining of Polymers, Ceramics, and Composites, 157-166 , 2024 2024 Citations: 2
Influence of the fruit waste fillers on the thermal, mechanical, and morphological properties of flax/epoxy composites S Chaudhary, S Gairola, H Sharma Proceedings of the Institution of Mechanical Engineers, Part L: Journal of … , 2024 2024 Citations: 5
An initial investigation to explore the feasibility of fruit waste fillers for developing sustainable thermoplastic composites H Sharma, I Singh, JP Misra Proceedings of the Institution of Mechanical Engineers, Part L: Journal of … , 2023 2023 Citations: 11
Sustainable Composites Using Fruit Waste: An Experimental Investigation H Sharma, JP Misra, I Singh International Conference on Advances in Materials Processing: Challenges and … , 2022 2022
Characterization and optimization of pistachio shell filler-based epoxy composites using TOPSIS S Gairola, H Sharma, I Singh Advances in Micro and Nano Manufacturing and Surface Engineering … , 2022 2022 Citations: 3
Composites Using TOPSIS S Gairola, H Sharma, I Singh Advances in Micro and Nano Manufacturing and Surface Engineering … , 2022 2022
Effect of particle size on physical, thermal and mechanical behaviour of epoxy composites reinforced with food waste fillers H Sharma, I Singh, JP Misra Proceedings of the Institution of Mechanical Engineers, Part C: Journal of … , 2021 2021 Citations: 29
Moisture and flammability behaviour of flax fibre and natural fillers-based hybrid epoxy composites SK Chaudhary, H Sharma, G Kumar Advances in Engineering Design: Select Proceedings of ICOIED 2020, 385-392 , 2021 2021 Citations: 1
Effect of walnut shell filler on mechanical properties of jute-basalt hybrid epoxy composites P Dhiman, H Sharma Materials Today: Proceedings 44, 4537-4541 , 2021 2021 Citations: 27
Friction and wear behaviour of epoxy composites reinforced with food waste fillers H Sharma, JP Misra, I Singh Composites Communications 22, 100436 , 2020 2020 Citations: 45
Environment Effect on Impact Strength of Pistachio Shell Filler-Based Epoxy Composites. S Gairola, S Gairola, H Sharma Advances in Applied Mechanical Engineering., 801-808 , 2020 2020 Citations: 3
Evaluation of dynamic properties of citrus limetta peel based epoxy composites H Sharma, I Singh, JP Misra Materials Today: Proceedings 27, 2273-2276 , 2020 2020 Citations: 10
Mechanical and thermal behaviour of food waste ( Citrus limetta peel) fillers–based novel epoxy composites H Sharma, I Singh, JP Misra Polymers and Polymer Composites 27 (9), 527-535 , 2019 2019 Citations: 57
MOST CITED SCHOLAR PUBLICATIONS
Mechanical and thermal behaviour of food waste ( Citrus limetta peel) fillers–based novel epoxy composites H Sharma, I Singh, JP Misra Polymers and Polymer Composites 27 (9), 527-535 , 2019 2019 Citations: 57
Friction and wear behaviour of epoxy composites reinforced with food waste fillers H Sharma, JP Misra, I Singh Composites Communications 22, 100436 , 2020 2020 Citations: 45
Impact behavior of pine needle fiber/pistachio shell filler based epoxy composite S Gairola, S Gairola, H Sharma, PK Rakesh Journal of Physics: Conference Series 1240 (1), 012096 , 2019 2019 Citations: 34
Effect of particle size on physical, thermal and mechanical behaviour of epoxy composites reinforced with food waste fillers H Sharma, I Singh, JP Misra Proceedings of the Institution of Mechanical Engineers, Part C: Journal of … , 2021 2021 Citations: 29
Effect of walnut shell filler on mechanical properties of jute-basalt hybrid epoxy composites P Dhiman, H Sharma Materials Today: Proceedings 44, 4537-4541 , 2021 2021 Citations: 27
Introduction to green composites H Sharma, UK Komal, I Singh, JP Misra, PK Rakesh Processing of green composites, 1-13 , 2019 2019 Citations: 21
Lignocellulosic polymer composites: Processing, challenges, and opportunities UK Komal, H Sharma, I Singh Processing of Green Composites, 15-30 , 2019 2019 Citations: 13
An initial investigation to explore the feasibility of fruit waste fillers for developing sustainable thermoplastic composites H Sharma, I Singh, JP Misra Proceedings of the Institution of Mechanical Engineers, Part L: Journal of … , 2023 2023 Citations: 11
Evaluation of dynamic properties of citrus limetta peel based epoxy composites H Sharma, I Singh, JP Misra Materials Today: Proceedings 27, 2273-2276 , 2020 2020 Citations: 10
Physio-mechanical and thermal behavior of kenaf ( Hibiscus cannabinus L.) fiber-reinforced epoxy composites: effect of eco-friendly treatment P Negi, P Bhatt, H Sharma, GS Brar Biomass Conversion and Biorefinery 15 (10), 15427-15436 , 2025 2025 Citations: 6
Influence of the fruit waste fillers on the thermal, mechanical, and morphological properties of flax/epoxy composites S Chaudhary, S Gairola, H Sharma Proceedings of the Institution of Mechanical Engineers, Part L: Journal of … , 2024 2024 Citations: 5
Epoxy composite dust reinforced novel polypropylene composites: An eco‐friendly approach toward sustainable resource management H Sharma, S Gairola, JP Misra, I Singh Polymer Engineering & Science , 2024 2024 Citations: 4
ARTIFICIAL INTELLIGENCE BASED TOOL FOR PREDICTING OF DAMAGE DURING DRILLING OF FRP’S H Sharma, UK Komal, I Singh, D Kumar, JP Misra 21st International Conference on Composite Materials, Xi’an , 2017 2017 Citations: 4
Characterization and optimization of pistachio shell filler-based epoxy composites using TOPSIS S Gairola, H Sharma, I Singh Advances in Micro and Nano Manufacturing and Surface Engineering … , 2022 2022 Citations: 3
Environment Effect on Impact Strength of Pistachio Shell Filler-Based Epoxy Composites. S Gairola, S Gairola, H Sharma Advances in Applied Mechanical Engineering., 801-808 , 2020 2020 Citations: 3
Preliminary studies into polypropylene composites reinforced with fruit waste biomass: A choice towards sustainability H Sharma, S Gairola, JP Misra, I Singh Physica Scripta , 2024 2024 Citations: 2
Machine Learning Approaches for Drilling GFRP Laminate: A Study for Thrust Force and Torque-induced Damage H Sharma, PK Rakesh, I Singh Forming and Machining of Polymers, Ceramics, and Composites, 157-166 , 2024 2024 Citations: 2
The Mechanical Properties of Pine Needle Fiber‐Reinforced Polymer Composites Under Different Environments PK Rakesh, KG Melese, S Gairola, H Sharma, S Rajkumar Engineering Reports 7 (10), e70376 , 2025 2025 Citations: 1
Moisture and flammability behaviour of flax fibre and natural fillers-based hybrid epoxy composites SK Chaudhary, H Sharma, G Kumar Advances in Engineering Design: Select Proceedings of ICOIED 2020, 385-392 , 2021 2021 Citations: 1
Sustainable polypropylene composites reinforced with Citrus limetta peel: Effects on mechanical performance and crystallinity A Misra, H Sharma, T Sudhakar Proceedings of the Institution of Mechanical Engineers, Part L: Journal of … , 2026 2026