Advancements in Polymer Technology

The current research work deals with the development of environment-friendly coatings with fouling release ability based on polydimethylsiloxane (PDMS) and polyurethane (PU) for marine applications. PU was synthesized using isophorone diisocyanate (IPDI) and polyethyleneglycol (PEG) and blended with PDMS. FTIR spectroscopy confirms the synthesis of PU and the successful interaction of PDMS components with the PU domain. The properties of PU/PDMS based films were evaluated in terms of mechanical strength, solubility, chemical resistance, water absorption, thermal stability, glass transition temperature (Tg), and morphology. The NCO:OH ratio of 1.4:1 and PU:PDMS ratio of 85:15 was found to be the optimum composition. GPTMS-treated nanosilica was also incorporated at a loading of 2 wt% within the PU/PDMS system. Subsequently, the optimized formulation of PU/PDMS was coated on metal substrates and exposed to marine water containing algal colonies. The modification of the PU/PDMS blend with nanosilica was also investigated to evaluate the quality of the coating.

Bacterial cellulose (BC) holds great significance as a sustainable raw material in the food, biomedical, cosmetic, electronic, and paper industries. A high concentration of carbon sources and other media components is required to increase the yield of BC, which increases the overall bioprocess cost. Thus, finding alternative substrates and developing optimizing strategies for the cost-effective production of BC becomes indisputable. In this study, the impact of tea leaves and sugar concentration, surface area to depth ratio, scaled-up volume, and different varieties of tea leaves on the production of BC from fermented tea or kombucha (kombucha-derived bacterial cellulose or KBC) has been studied in detail. It was found that 8.0% (w/v) sugar and 0.6% tea leaf concentration gave an optimum KBC productivity of 11.91 ± 0.18 g/L/d. A surface area to depth ratio of 186 cm gave the maximum productivity (29.74 ± 0.65 g/L/d) of KBC. Upscaling of fermenter volume resulted in an approximately two-fold increase in wet weight of KBC. Furthermore, the study also considers the reuse of spent tea leaves and processing waste given environmental sustainability. These outcomes aim to advance the understanding of KBC production, providing insights into maximizing its production for sustainable biomaterial synthesis with diverse applications.

Recent statistics and trends indicate that fossil fuels are the leading cause of carbon dioxide emissions. As a multi-stage supply chain model with a well-organized report on capturing, utilizing, converting, and storing carbon dioxide, CCUS (Carbon Capture, Utilisation, and Storage) is critically assessed. In this paper, we describe using the amino acid in aqueous form as a green, environmentally friendly method of CO₂ capture at ambient temperature (298.15 K) and pressure of around 1.5 Mpa. We studied the process of CO₂ capture in a high-pressure triple injection setup equipped with a data acquisition system to monitor and record input values in real-time. Each experiment was done thrice to determine the saturation (estimate carbon dioxide uptake capacity) and the feasibility of designing a continuous process with minimum percentage error. The experimentation was done in an optimized concentration of amino acids with water in a 100 ml reactor and was also projected for industrial scale-up in a 100 L reactor. To interpret the impact of mass transfer on CO₂ uptake, a common surfactant, sodium dodecyl sulfate (SDS) and water, was utilized, and the results were reported. The capacity of such amino acids is majorly analyzed concerning comparative analysis with other amino acids, amines, amides, etc., for carbon capture.

This study explores the development of composites by homogeneously blending ABS (Acrylonitrile Butadiene Styrene) with natural calcined mica powder at varying mixing ratios. The melt mixing method in a twin-screw extruder was employed to prepare a mixture of virgin ABS granules and natural calcined mica powder, and the resulting compounded pellets were utilized for the fabrication of mechanical test specimens. Tensile, flexural, and impact tests were conducted according to relevant national and international standards, employing an injection molding machine. The investigation delves into the assessment of ABS/MICA composites across different ratios of ABS infusion, with a focus on mechanical, thermal, chemical, and physical characteristics. The interaction between ABS and MICA was confirmed through Fourier Transform Infrared (FTIR) analysis, providing insights into the molecular level bonding within the composite. Thermal stability of the composite was studied through TGA (Thermogravimetric) and DSC (Differential Scanning Calorimetry) analysis. Results revealed that the composite exhibited superior thermal stability compared to virgin ABS. These findings were further correlated with the mechanical properties of the composites, demonstrating a promising relationship between thermal stability and mechanical performance. The study indicates that increasing the loading of mica into ABS materials leads to a rise in brittleness in the resulting composites. Optimal properties were observed when the mica loading reached 15%, suggesting a balance between reinforcement and flexibility. In conclusion, the synergistic effects of ABS/MICA composites have been explored comprehensively, providing valuable insights into the interplay of materials and their resulting properties. This research contributes to the understanding of composite material design for applications that demand a combination of mechanical robustness, thermal stability, and chemical resistance.

Kombucha bacterial cellulose (KBC) is an exopolysaccharide synthesized by bacteria in the process of fermenting kombucha tea. It has a distinct three-dimensional reticulated network made of cellulose nanofibers, which gives it robust mechanical qualities, a high water-holding capacity, and outstanding suspension stability. Cellulose acetate (CA) is a very important derivative generated via transesterification. As an economical ester of cellulose, CA is used in retractable films, fibers, filters, and tubes because of its good mechanical qualities, low density with larger surface area, biodegradability, and nontoxicity. This study focuses majorly on two aspects: (1) the production of high-value yields (cellulose acetate) by using low-value waste (tea processing waste) for the cultivation of bacterial cellulose to address the challenges associated with high production costs, plastic waste, and limitations of utilizing cellulose derivatives (2) Selection of the better acetylating agent among acetic acid and acetic anhydride for conversion of KBC. CA was synthesized via two methods: using acetic acid (CA1) and acetic anhydride (CA2) wherein using the first method, the % acetyl group of 11.82 was obtained, whereas a two-fold increase in the % acetyl group (23.65) was observed using the second method. Further, the characteristic peaks observed in FTIR analysis confirmed the acetylation of KBC. CA2 showed lower crystallinity and higher thermal stability than CA1. Thus, this study demonstrated the synthesis of CA using acetic anhydride as a better method from KBC for use as a sustainable alternative to existing plastic-based and plant-based cellulose acetates. The novelty of this research lies in its innovative approach and comparative study to produce cellulose acetate by utilizing low-value waste to achieve a high-value output like better yield, crystallinity, and thermal stability. It presents an environmentally friendly substitute for plastic-based cellulose acetates.

Polymeric waste, especially plastics, is a pressing global environmental challenge. This pioneering research amalgamates computer vision, ResNet50 architecture, ReLU activation functions, and IoT communication to transform polymeric waste detection and management. Leveraging Convolutional Neural Networks (CNNs) like ResNet50, the model achieves outstanding accuracy, surpassing 98.7% in identifying diverse polymeric waste items. The integration of ReLU activation functions enhances the network's ability to discern intricate waste patterns, resulting in an impressive F1 score exceeding 98%. Training with an extensive and meticulously annotated dataset ensures adaptability in recognizing varied polymeric waste forms, guaranteeing high accuracy in real-world applications. The IoT integration through a GSM module has played a pivotal role in enabling real-time communication upon waste detection. Recent successful tests showcased the system's seamless transmission of messages from the detection setup to a control room upon polymeric waste identification. Specifically, real-time wrapper detection illustrated the system's efficacy by promptly notifying the designated control room, showcasing its practical applicability and swift responsiveness. This fusion of computer vision and IoT technologies establishes a versatile framework applicable across diverse environments, reshaping waste management in urban areas, public spaces, and recycling facilities. Its scalability positions it as a promising solution to curb polymeric waste proliferation, proactively reducing the ecological footprint of plastics and fostering environmental conservation. This research introduces a transformative paradigm in polymeric waste management. The integration of advanced technologies not only accurately identifies and categorises waste but also triggers immediate responses, marking a significant stride towards efficient and sustainable waste management practices globally. The successful incorporation of IoT via GSM communication, enabling real-time alerts to a control room, highlights the system's practicality and readiness for immediate integration into waste management infrastructures.

Formaldehyde emissions from wood composites, commonly used in wood-based panel industries, pose significant environmental and health concerns. This research aimed to assess the effectiveness of Polymate-777P, a commercially branded formaldehyde scavenger, in mitigating formaldehyde emissions from plyboard manufactured using phenolic resin as a binder. The study involved a comprehensive evaluation of formaldehyde emission reduction in wood composites. A series of experiments were conducted to investigate the impact of Polymate-777P by using 0.5, 1.0, 1.5, 2.0, and 3.0% concentrations of the ply board bonded with phenol formaldehyde resin. The impact of the scavenger Polymate-777P on the properties of Phenol formaldehyde resin, including parameters such as viscosity, pH, gelation time, and free formaldehyde content, was assessed. Additionally, an evaluation of the physico-mechanical properties and formaldehyde emission of the resulting plywood was conducted. The findings of the study demonstrate that the manufactured plywood met the Japanese industrial standard F*** emission requirement (≤0.50 mg/L) and European E₀ classes when Polymate-777P was employed as a scavenger at concentrations of 1.5% or higher. The study also revealed that scavenger not only reduces the formaldehyde emission of the ply board but also increases the bonding properties and technological properties of the board to some extent. The study shows the feasibility of using Polymate-777P as a formaldehyde scavenger and offers a promising solution to minimize formaldehyde emissions, contributing to improved environmental and health outcomes in wood composite industries.

Waste paper classified as municipal solid waste is often dumped in landfills or incinerated. As a low-cost source of lignocellulosic elements, the waste paper can be converted into cellulose microcrystals. Microcrystalline cellulose (MCC) is becoming increasingly important as an alternative to non-renewable and limited fossil fuels due to its broad use in sectors such as food, pharmaceutical, cosmetic, and polymer composites. Because of its sustainability, non-toxicity, affordability, biodegradability, outstanding mechanical properties, and high surface area, MCC has steadily earned a greater amount of attention in recent years. To meet the growing need for manufacturing new types of MCC-based products on an industrial scale, novel sources, separation procedures, and treatments are continuously being developed. This study aims to extract MCC from waste office paper as a novel source through acid hydrolysis. The synthesized MCCs were subjected to structural and compositional characterization. The MCCs obtained from both sources exhibited a crystalline nature with a particle size distribution of 0.6–1.1 µm, and the length-to-cross-section ratio was found to be 10:1. The FTIR analysis revealed the absence of peaks corresponding to lignin in the extracted MCC. The extracted MCC showed a yield percentage of 79.5 ± 1.2%. Thus, waste office paper can act as a potential and sustainable source for extraction of MCC for application in various fields.