Water solubility of poly(vinyl alcohol) (PVA) advantageously prevents the formation of harmful micro- and nano-plastics, but it currently lacks practical viability due to its poor water resistance. In this study, PVA films were reinforced with acid-treated palm kernel shell biochar to enhance their water resistance and wet strength. Incorporation of the treated biochar resulted in significant improvements in mechanical strength, reduced swelling, and higher gel content upon immersion in water, indicating enhanced network stability. At 5 wt% biochar loading, the films exhibited a significant drop in the swelling ratio, decreasing from 296.2% (neat PVA) to 133.1%, while gel content of the corresponding films increased from 76.5% to 93.0%. The most significant mechanical reinforcement occurred at a 3 wt% loading, which yielded a 25.9% increase in tensile strength. Furthermore, the benefits of biochar incorporation were highly evident in wet strength analyses where the samples were subjected to tensile test right after 24 and 48 h of water immersion. The PVA/biochar films maintained a tensile strength of at least five times greater than that of the neat PVA film. By valorizing a renewable waste material to enhance polymer performance, this approach demonstrates a strategic pathway toward practical yet environmentally friendly plastics.

This study presents a surface modification strategy for inherently hydrophobic polyolefin nonwoven substrates via UV-induced grafting of hydrophilic polymers to enhance separator electrochemical performance. Three polymer systems were investigated: poly (acrylic acid) (PAA); a copolymer of acrylic acid (AA) and poly (ethylene glycol) diacrylate (PEGDA) (D0.5E25); and a terpolymer of AA, PEGDA, and styrene (D0.5E25S10). Comprehensive characterization inclusive of FTIR spectroscopy, FESEM-EDX analysis, electrolyte uptake, and contact angle measurements revealed substantial alterations in the physicochemical properties. The modified polyolefin separators transitioned from a non-wetting state to exhibiting high electrolyte absorption capacities of 200–240

Natural rubber is a renewable biopolymer valued for its exceptional elasticity, resilience, and mechanical durability, making it an attractive alternative in the expanding landscape of bio-based materials. However, its inherently high molecular weight and limited solubility hinder its direct incorporation into advanced polymer application. A controlled degradation process therefore represents a crucial strategy to transform natural rubber into low-molecular-weight liquid rubbers with tunable reactive functionalities. This review provides a comprehensive overview of established and emerging controlled degradation pathways including mechanical, thermal, oxidative, and photochemical methods while detailing their mechanisms, reaction parameters, and resulting structural characteristics. The chemical oxidative and photochemical approaches had been drawn into attention as they enable selective cleavage of C–C or C = C bonds to yield functional oligomers bearing hydroxyl and carbonyl end groups. Recent advances in photocatalytic and green oxidant systems further highlight the potential for environmentally benign depolymerization. By integrating mechanistic insights, this review underscores controlled natural rubber degradation as a versatile platform for generating functionalized bio-based oligomers suitable for various downstream applications.

This research aimed to design biocompatible polymeric surfactants as additives to natural rubber latex (NRL) and the mechanical properties of the latex films were evaluated thereafter. Both anionic and non-ionic surfactants, APS and NPS, were successfully synthesised from palm-based oleic acid by polyesterification, with their ester linkages verified by FTIR analysis. Both surfactants possess good thermal stability with thermal decomposition temperatures above 200 °C. They were biocompatible and non-cytotoxic, as evidenced by high cell viability > 80

Separator membrane is an essential element within every battery system, having a significant influence on both safety and electrochemical performance. With rejuvenated interest in rechargeable alkaline zinc batteries, such as zinc-air, nickel-zinc (NiZn), and zinc-manganese (Zn-MnO2) batteries, there has been an increased focus on scrutinizing the role of each component in the battery system, including the separator. This scrutiny arises from the realization that separator properties are vital for influencing battery cycle life, discharge capacity, rate capability, and capacity retention. Various types of separators have been thoroughly investigated for their suitability in rechargeable alkaline zinc batteries, including nonwoven, microporous, inorganic, and polymer electrolyte membranes. Primary challenges associated with rechargeable alkaline zinc batteries are zincate ion crossover and dendrite penetration of the separator, both of which are known to adversely affect the battery performance and safety. Significant efforts have been dedicated to modifying conventional membranes, as well as to develop new separators tailored to address the challenges encountered by these battery systems. This review provides comprehensive overview on the challenges in development of alkaline zinc batteries, different types of separators utilized in rechargeable alkaline zinc batteries, and the optimization strategies employed to enhance battery performance.

Polyolefin nonwoven separators have been widely used in alkaline batteries. However, their hydrophobic nature limits wettability and electrolyte absorption, resulting in suboptimal battery performance. To address this, hydrophilic polymer such as polyacrylic acid is commonly grafted onto the polyolefin membranes. Despite this, alkaline zinc batteries with such separators often experience premature failure during cycling. This study aims to enhance the cycling stability of alkaline nickel-zinc (NiZn) batteries by UV-grafting novel copolymers of acrylic acid, styrene, and divinylbenzene onto nonwoven polyolefin membranes. The grafting was confirmed by FTIR, TGA, and FESEM-EDX analyses. Wettability improvements were assessed through electrolyte absorption, retention, and contact angle measurements. NiZn coin cell test showed a 10-fold improvement in cycle life with the copolymer-grafted separator compared to the polyacrylic acid-grafted separator and achieved a discharge capacity of 346 mAh/g at a charge/discharge rate of 0.3 C. Failure analysis revealed that the polyacrylic acid-grafted separator led to excessive ZnO adhesion on the separator, contributing to early cell failure. In contrast, the copolymer-grafted separator showed reduced ZnO adherence, contributing to enhanced cycling performance. This study demonstrates a simple yet effective modification of polyolefin separators with novel copolymer grafts, resulting in a significant improvement in the cycling performance of NiZn batteries.

This work reports the potential of natural rubber (NR) and its derivatives as bio-based alternatives for producing polyurethane (PU). Natural rubber latex was first epoxidized and then subjected to oxidative degradation to yield liquid epoxidized natural rubber (LENR). The resulting liquid rubber was further hydrolyzed under acidic condition to yield a rubber-based polyol (LENRX), where its epoxide groups were converted into secondary hydroxyl groups. Unlike conventional linear polyols used in PU synthesis, this study introduces LENRX as both a co-polyol and a crosslinking agent in PU coatings for the first time. A series of PU samples were formulated with varying LENRX-to-polyethylene glycol (PEG) ratios, using isophorone diisocyanate (IPDI) as the curing agent, to systematically tailor the film properties. Spectroscopic analyses, including FTIR and 1H-NMR, were performed to confirm the products at each synthesis stage, culminating in the formation of PU. In addition, comprehensive characterization inclusive of physicochemical, mechanical, and thermal properties was carried out. Increasing LENRX content improved surface hardness (up to 8H), tensile strength (up to 63.08 MPa), and chemical resistance, while higher PEG content imparted softness and flexibility (elongation at break > 300

This study highlights the potential of natural rubber (NR) as a renewable, bio-based feedstock to produce functional polyols. Through a controlled series of reactions (epoxidation, oxidative degradation, and acid hydrolysis), natural rubber was successfully converted into a tunable polyol with adjustable hydroxyl functionality. By varying the degree of epoxidation in the initial step, the properties of the resulting polyol can be tailored for diverse applications, underscoring the flexibility of this approach. Structural confirmation at each synthesis stage was achieved using FTIR and H-1-NMR spectroscopy, verifying the introduction of hydroxyl groups and the reduction in molecular weight. To demonstrate its applicability, the rubber-derived polyol was reacted with isophorone diisocyanate (IPDI) to synthesize a bio-based polyurethane (PU), serving as one potential validation of its functionality. The PU film exhibited excellent performance, including high hardness (> 3H pencil hardness), strong chemical resistance, and good thermal stability. These properties are correlated with the polyol's hydroxyl content and high crosslinking density in the PU. The findings position NR as a versatile and eco-friendly platform for polyol production. By leveraging its renewable origin and tunable chemistry, NR-based polyols could significantly reduce reliance on fossil fuel-derived precursors across multiple industries, advancing the shift toward greener material solutions.

Dispersants play a vital role in stabilizing pigment dispersions in the surface coating industry. This study addresses the growing need for versatile, high-performance additives by advancing the development of a polymeric dispersant, PD-1, originally designed with carboxyl anchoring groups from fatty acid. While PD-1 demonstrated effectiveness with titanium dioxide pigments, its limited compatibility with other pigments hindered broader application. To overcome this limitation, we developed PD-A1, a modified dispersant featuring an azole anchoring group grafted through amidation of the PD-1 carboxyl group using 1-(3-aminopropyl) imidazole. The structural modification was confirmed via FTIR and H-1-NMR spectroscopy. PD-A1's performance was evaluated with four diverse pigments and it consistently achieved lower viscosity, enhanced stability, and improved compatibility across all pigment systems. Nitrocellulose coatings prepared with PD-A1-based dispersions exhibited superior optical and mechanical properties, including enhanced gloss, transparency, jetness, tinting strength, and favorable rub-out performance. Thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) analysis confirmed the effective adsorption of PD-A1 on various pigment surfaces, underscoring the efficacy of the azole group as a universal anchoring site. This advancement represents a significant step toward developing a universal dispersant, capable of addressing the diverse requirements of the surface coating industry while aligning with the industry's shift toward sustainable and bio-based solutions.

Coating natural rubber gloves with a layer of polymeric film is an essential process to improve donning properties of the article. The objective of this study is to develop a novel terpolymer, styrene-butyl acrylate-isoprene (St-BAIso) resin for rubber gloves coating application. St-BA-Iso terpolymer was synthesized via emulsion polymerization, and subsequently formulated as polymeric coating for natural rubber films. The synthesized emulsion terpolymer and its coating performance were characterized via spectroscopic, thermal, and physical tests. Several commercial styrene-butadiene-rubber (SBR) and polyurethane (PU) resins which are commonly used for the same purpose were included in this study to benchmark the performance of the newly developed St-BA-Iso coating. Carefully designed methodology and formulation have allowed the terpolymer synthesis to achieve >= 95 % conversion, comprise of smaller particle size, and has desirable glass transition temperature. Apart from that, the surface tension and molecular weight are comparable to those of commercial resins. In terms of coating performance, St-BA-Iso coating outperformed the other resins used in this study by demonstrating impressive smoothness on the coated surface. Rubber film coated with the terpolymer recorded lower coefficient of friction, better anti-tack property, as well as lesser cracking or delamination. Effect from core-shell polymerization technique on the resultant film properties was elucidated in this study as well. In addition to the superior properties, the all-liquid monomers formulation to produce St-BA-Iso terpolymer makes it more industrially friendly, and the monomers are relatively less toxic in comparison to those used in the synthesis of SBR or PU.

A layer of polymeric coating with low coefficient of friction (COF) on rubber glove surface is necessary for quick and easy donning. The current study elucidates the effect of varying the composition of soft and hard monomers in novel styrene-butyl acrylate-isoprene (St-BA-Iso) terpolymer on the properties of emulsion and its coating performance on rubber glove substrate. Styrene contributed to the terpolymer's overall strength and smooth surface. Butyl acrylate, as a soft monomer, imparted flexibility and lower the glass transition temperatures of the coating. Isoprene, another soft monomer, further contributed to the coating's flexibility and, when combined with butyl acrylate, played a role in maintaining coating adhesiveness. Terpolymers with higher loading of BA and Iso was found to produce films of relatively low glass transition temperature, Tg and higher COF. Meanwhile, high loading of St in the terpolymer resulted with smooth coating surface but exhibited severe delamination from the substrate when stretched due to the high rigidity and poor coating adhesion. St-40 terpolymer with 4 St: 3 BA: 3 Iso composition was able to produce a coating with well-balanced properties, producing smooth film (COF < 0.1) with moderately high Tg (24 C), while retaining good coating adhesion on the rubber substrate.

Adverse environmental impacts from the increasing volume of synthetic rubber waste and the overexploitation of fossil fuels have heightened the awareness on sustainability in the synthetic rubber industry. The current use of synthetic rubbers is not sustainable, as they are primarily produced from fossil-derived monomers, are non-biodegradable, and are difficult to recycle. In this study, poly(isoprene-co-acrylonitrile) incorporated with oleic acid (XNIR OL) was synthesized using free radical emulsion polymerization. Oleic acid, a prevalent fatty acid in various vegetable oils, was used in the XNIR OL formulation instead of the typical fossil-derived acids found in carboxylated nitrile rubber. The incorporation of oleic acid in the synthetic rubber was confirmed through spectroscopic analyses and acid value test. Characterizations were conducted on the rubber film to investigate the effects of oleic acid incorporation on the mechanical properties, thermal properties, oil resistance and biodegradability. The vulcanized XNIR OL film exhibited rubbery behaviour at ambient temperature, with a glass transition temperature of − 21.9 °C and satisfactory thermal stability. XNIR OL demonstrated an elongation at break of 379

This manuscript elucidates the preparation and utilization of liquid epoxidized natural rubber (LENR) with 50 mol% epoxidation level (LENR50) as a polymeric plasticizer for poly(vinyl chloride) (PVC), and further immobilization of the plasticizer in the plastic matrix through subsequent ultraviolet (UV)-curing treatment. The plasticizing effect induced by LENR50 at 50 wt% loading was evident with a reduction of T-g from a high of 72.0 to 11.4 degrees C. Positive enhancements were also documented in the mechanical properties of the LENR50-plasticized PVC, specifically the big improvement in elongation at break and elastic modulus, from 106% to 430%, and from 646 to 7 MPa, respectively. The UV-treated PVC/LENR film also exhibited superior resistance to migration compared with formulations with conventional plasticizers such as di-2-ethylhexyl phthalate (DEHP) and triethyl-2-acetyl citrate (ATEC). A similar outcome was recorded in the leaching resistance test, where LENR50 had the best resistance to leaching in four different solvents (water, soap solution, ethanol, and toluene). The LENR50-plasticized PVC film recorded the lowest weight loss following 24 h immersion in both hydrophilic and lipophilic solvents. The findings from this study suggest that LENR50 could serve as an efficient bio-based polymeric plasticizer for PVC.

Bio-based coatings are becoming more relevant today due to depleting fossil resources as well as the adverse environmental impacts from the wide usage of petrochemicals in coating formulations. The growing interest in this research area is evident from the increasing volume of reports on the innovation of new coating binders derived from various renewable resources such as plant oil, fatty acids, cellulose, cardanol, etc. Although this is a positive development, many of the bio-based coatings are however still formulated as solvent-borne coatings, and the vapour emitted during curing of such coatings is known to be one of the major pollutants from the coating industry. To maximize the environmental benefits of bio-based coatings, it is necessary to adopt a curing mechanism or formulation which eliminates the use of organic solvents. The current review paper details the recent progress of bio-based coatings in waterborne systems, with specific focus on synthetic route and the selection of monomers derived from renewable resources used to develop such coating. The scope of this review paper includes waterborne bio-based polyurethane coatings, waterborne bio-based polyester and alkyd coatings, and waterborne bio-based epoxy coatings. Detailed discussion on the modifications adopted to induce specific properties in some of the coatings to serve as flame retardant, antimicrobial and anticorrosion coatings were elaborated as well.

Rubber has become essential in everyday life, but the poor degradation rates of natural rubber products present an environmental challenge. This study focused on the development and characterization of oxo-biodegradable rubber by modifying vulcanized natural rubber (VNR) with pro-degradant additives (PDA) such as iron (III) stearate (VNR-FeSt) and cobalt (II) stearate (VNR-CoSt). No observable degradation of the PDA-incorporated latex films occurred during the preparation processes of the film which include rubber latex coagulant dip-ping and vulcanization. The addition of PDA also had minimal effects on the mechanical properties of the latex films. While latex VNR without PDA was relatively stable to oxidative degradation at 65 degrees C for eight weeks, the formation of carbonyl and hydroxyl functional groups in VNR-CoSt and VNR-FeSt indicate that the PDAs facil-itated oxidative degradation the rubber. VNR-CoSt and VNR-FeSt showed significantly greater decreases in weight and gel content than neat VNR, with CoSt being most effective for enhancing thermal oxidative degra-dation. Growth parameter analysis showed that the addition of oxo-biodegradable latex films to the soil had little effect on the nutrient content of spinach, in line with the soil analysis. These data support the promotion of oxo-biodegradable rubbers as a promising sustainable alternative to conventional rubbers, with the potential to aid in rubber waste management in the agriculture sector.

Increasing demand for durable rubber and rapid advancement in the automotive sector has made oil-resistant rubber an increasingly important material. Among them, nitrile rubber (NBR) is the most iconic due to its extraordinary oil resistance contributed by the polar nitrile pendant groups. Synthesis of NBR, however, is highly hazardous due to the explosive nature of the gaseous monomer butadiene. In this work, poly(isoprene-co-acrylonitrile) (NIR) was synthesized using free radical emulsion polymerization, with liquid monomer isoprene as the diene in the rubber formulation. The spectroscopic analysis confirmed the formation of NIR and indicated that the polymerized isoprene in the rubber is predominantly of 1,4-microstructure. A series of rubbers with different contents of acrylonitrile were produced and the mechanical, thermal, as well as oil resistant property of the resultant rubber films were evaluated. Vulcanized NIR films displayed glass transition temperatures from -9.4 to 20.2 & DEG;C, suggesting that the polymers are rubbery at ambient and higher temperatures. The NIR rubber films exhibited excellent oil resistance with less than 2% swelling in mineral oil, good thermal stability with onset degradation temperature in the range of 361.3 to 369.9 & DEG;C, and adequate mechanical strength from 1.61 to 8.23 MPa. The synthesized NIR rubber has the potential to serve as an alternative to NBR which had been traditionally used for oil resistance applications.

Compatibility of polymeric dispersant with other components in a coating is an important criterion to formulate coating with desirable optical properties, particularly surface gloss. This study detailed the synthesis of polymeric dispersant incorporated with fatty acid pigment anchoring group, PD-1, and its subsequent application in various types of organic coating binder systems. 1H-NMR analysis indicated about 98

Innovation of new products from renewable resources are important for sustainable development. In this work, novel rubber-integrated palm oil-based alkyd resins were prepared using palm oil, glycerol, diacids, and liquid epoxidized natural rubber (LENR50). The synthesis started with alcoholysis of glycerol by palm oil to produce predominant mixture of monoglycerides, followed by polycondensation with diacids to form alkyd chain. In addition to glycerol, LENR50 was introduced as bio-based polyol for the alkyd synthesis. The rubber prepolymer was chemically integrated into the alkyd chain via the reaction between its epoxide or hydroxyl groups with COOH of diacids during polycondensation. Resultant alkyds were mixed with reactive diluent (styrene), crosslinker (trimethylolpropane triacrylate) and photoinitiators (benzophenone and 1-hydroxycyclohexyl phenyl ketone), and the mixtures were cured under UV irradiation. Introduction of LENR50 into the coating formulation has reduced the curing time, as well as improved some of the film properties of the coatings. Some of the LENR50-based coatings required as short as 3 mins of UV irradiation to form dry-hard films, while the control samples required much longer time. There was also notable increase in the gel content of the LENR-based alkyd coating, suggesting that the polyfunctionality of LENR50 could have increased the extent of crosslinking in the cured film. Other improvement recorded includes pencil hardness, film adhesion, solvent resistance, water resistance, and corrosion resistance. Thermal stability of the alkyd coatings is also reasonably good for general purpose coating applications. The findings from this study suggest that LENR50 could serve as an alternative polyol in synthesis of bio-based polyester binder for surface coating.

A persistent increase in the amount of rubber waste in the environment could herald the next environmental crisis. Elastomeric properties of natural rubber are relevant and essential for a wide range of applications, and because of the heavy utilization, there is a huge amount of rubber waste produced. Rubber waste, like most hydrocarbon polymers, does not readily degrade when discarded in the environment, resulting in excessive accumulation over time. Hence, novel or innovative approaches to improving natural rubber degradability are required for better waste management. The aim of the present study is to evaluate the effectiveness of metal stearates in enhancing the thermal oxidative degradability of natural rubber. Natural rubbers were blended individually with cobalt (II) stearate and iron (III) stearate, and the compounded rubbers were subsequently thermally treated in an oxidative environment at 65 °C for up to 8 weeks. Throughout the degradation period, the rubber films were characterized by FTIR, 1H-NMR, 13C-NMR, water contact angle, molecular weight analysis, and thermogravimetric analysis. Rubber films compounded with metal stearates experienced 1200% increase in carbonyl content, significant increase in hydrophilicity, and reduction in molecular weight by greater than 80%. These changes are highly desirable in the context of oxo-biodegradable materials because they could facilitate the subsequent biotic degradation process. The findings in this study indicate that metal stearates are efficient in enhancing the rubber’s oxidative degradability. The technology may be adopted to innovate oxo-biodegradable rubbers for a more sustainable rubber consumption.

The use of pro-degradant additive (PDA) to enhance the oxidative degradability of polymers has been successful in hydrocarbon plastics, but few, if any studies have been conducted to evaluate the effect of PDA on natural rubbers. This study investigated thermal, and photo oxidative degradation of natural rubber facilitated by iron (III) stearate as PDA. For a total of eight weeks, natural rubber compounded with PDA was subjected to thermal and photo oxidation separately. Spectroscopic analysis was used to quantify changes in the chemical structure of the rubber, including the formation of carbonyl, hydroxyl, and ether linkages. The changes in the surface hydrophilicity, crystallinity, and thermal properties of the rubber throughout the degradation process were evaluated as well. PDA-containing natural rubber film exhibited greater oxidative degradation, as evidenced by a significant increase in carbonyl index, a decrease in water contact angle, and a lower decomposition temperature. Between the two modes of degradation, natural rubber was found to degrade better in the presence of light. The apparent improvement in the oxidative degradability of the rubber following the incorporation of the iron salt suggests that the material could be formulated or developed as oxo-biodegradable rubber to promote more sustainable consumption. Oxidative degradation is a crucial process that converts rubber into shorter chains with a higher concentration of oxygen-carrying functional groups, and these changes are required to support the subsequent biodegradation process, resulting in a more environmentally friendly material.