Latex Films Research Articles

Degradation of oxo-biodegradable rubber and its impact on ecosystem services

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 dipping 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 °C for eight weeks, the formation of carbonyl and hydroxyl functional groups in VNR-CoSt and VNR-FeSt indicate that the PDAs facilitated 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 degradation. 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.

High‐Energy‐Density Waterborne Dielectrics from Polyelectrolyte‐Colloid Complexes

AbstractTo meet the demands of miniaturization and integration of next‐generation power systems, a major challenge is to improve the energy density of used dielectric capacitors. Polymer nanocomposites are of great potential for high‐energy‐density capacitors. However, most of them are prepared via melt blending at high temperatures or solution processing in hazardous organic solvents, which are energy consuming and environmentally problematic. It has long remained economically and ecologically challenging to develop new dielectric materials. Here, a class of high‐energy‐density dielectrics made by electrostatically complexing polyvinylidene fluoride (PVDF) latex with oppositely charged chitosan in an aqueous phase is reported. At the charge neutralization point, the film of PVDF@Chitosan complexes demonstrates the highest breakdown strength (630 MV m−1) and recoverable energy density (10.1 J cm−3), which are respectively 279% and 421% higher than the bare PVDF latex film, and far beyond most of the conventional solvent‐ or melt‐processed polymer films. The largely improved capacitive performances are ascribed to the significant minimization of losses at the critical charge neutralization point. The concept can be extended to a wide range of colloids, including polystyrene latex and aqueous bentonite suspension, highlighting the versatility of the proposed approach to develop environmentally friendly high‐performance capacitors.

One-Step Synthesis of Self-Stratification Core-Shell Latex for Antimicrobial Coating

Herein, we describe a one-step method for synthesizing cationic acrylate-based core-shell latex (CACS latex), which is used to prepare architectural coatings with excellent antimicrobial properties. Firstly, a polymerizable water-soluble quaternary ammonium salt (QAS-BN) was synthesized using 2-(Dimethylamine) ethyl methacrylate (DMAEMA) and benzyl bromide by the Hoffman alkylation reaction. Then QAS-BN, butyl acrylate (BA), methyl methacrylate (MMA), and vinyltriethoxysilane (VTES) as reactants and 2,2'-azobis(2-methylpropionamidine) dihydrochloride (AIBA) as a water-soluble initiator were used to synthesize the CACS latex. The effect of the QAS-BN dosage on the properties of the emulsion and latex film was systematically investigated. The TGA results showed that using QAS-BN reduced the latex film's initial degradation temperature but improved its thermal stability. In the transmission electron microscopy (TEM) photographs, the self-stratification of latex particles with a high dosage of QAS-BN was observed, forming a core-shell structure of latex particles. The DSC, TGA, XPS, SEM, and performance tests confirmed the core-shell structure of the latex particles. The relationship between the formation of the core-shell structure and the content of QAS-BN was proved. The formation of the core-shell structure was due to the preferential reaction of water-soluble monomers in the aqueous phase, which led to the aggregation of hydrophilic groups, resulting in the formation of soft-core and hard-shell latex particles. However, the water resistance of the films formed by CACS latex was greatly reduced. We introduced a p-chloromethyl styrene and n-hexane diamine (p-CMS/EDA) crosslinking system, effectively improving the water resistance in this study. Finally, the antimicrobial coating was prepared with a CACS emulsion of 7 wt.% QAS-BN and 2 wt.% p-CMS/EDA. The antibacterial activity rates of this antimicrobial coating against E. coli and S. aureus were 99.99%. The antiviral activity rates against H3N2, HCoV-229E, and EV71 were 99.4%, 99.2%, and 97.9%, respectively. This study provides a novel idea for the morphological design of latex particles. A new architectural coating with broad-spectrum antimicrobial properties was obtained, which has important public health and safety applications.

Template-Directed Polymerization of Binary Acrylate Monomers on Surface-Activated Lignin Nanoparticles in Toughening of Bio-Latex Films.

Fabricating bio-latex colloids with core-shell nanostructure is an effective method for obtaining films with enhanced mechanical characteristics. Nano-sized lignin is rising as a class of sustainable nanomaterials that can be incorporated into latex colloids. Fundamental knowledge of the correlation between surface chemistry of lignin nanoparticles (LNPs) and integration efficiency in latex colloids and from it thermally processed latex films are scarce. Here, an approach to integrate self-assembled nanospheres of allylated lignin as the surface-activated cores in a seeded free-radical emulsion copolymerization of butyl acrylate and methyl methacrylate is proposed. The interfacial-modulating function on allylated LNPs regulates the emulsion polymerization and it successfully produces a multi-energy dissipative latex film structure containing a lignin-dominated core (16% dry weight basis). At an optimized allyl-terminated surface functionality of 1.04mmol g-1 , the LNPs-integrated latex film exhibits extremely high toughness value above 57.7MJ m-3 . With multiple morphological and microstructural characterizations, the well-ordered packing of latex colloids under the nanoconfinement of LNPs in the latex films is revealed. It is concluded that the surface chemistry metrics of colloidal cores in terms of the abundance of polymerization-modulating anchors and their accessibility have a delicate control over the structural evolution of core-shell latex colloids.

Natural rubber latex films with effective growth inhibition against S. aureus via surface conjugated gentamicin

Hospital-associated infections and related complications are of extreme concern in the healthcare sector since biofilms generated over material surfaces not only create turbulence in the healthcare practices followed but also ruin the device performance, and increased medication, leading to significant chances of drug resistance. Natural rubber latex (NRL) being the first choice for the manufacture of several conventional biomedical devices, it is essential to ensure the surfaces of the same are inherently inactive against most microorganisms. This study presents NRL film surface conjugated with a well-known antibiotic, gentamicin through an amide linkage to generate antibacterial activity to the surface with a significant growth inhibition rate, especially against Staphylococcus aureus. The NRL films were surface-oxidized under controlled acidic conditions to generate carboxyl groups exploring the unsaturation of the base monomer unit. The carboxyl group reacts with the amine groups of gentamicin facilitating its surface conjugation. The surface anchoring was authenticated by FTIR-ATR complimented further by contact angle measurement as a function of hydrophilicity and elemental analysis by EDX spectroscopy. The antibacterial efficacy of modified NRL films was evaluated using antibacterial drop test and the results indicated a substantial growth inhibition rate (>60%) against Pseudomonas aeruginosa and Staphylococcus aureus. The study could be further optimized and proposed as a viable route for the conjugation of active molecules over inert polymer molecules.

Microwave-assisted silver-doped zinc oxide towards antibacterial and mechanical performances of natural rubber latex film

Microwave-assisted silver-doped zinc oxide towards antibacterial and mechanical performances of natural rubber latex film

Photo‐responsive cellulose nanocrystal modified fluorinated polyacrylate based on coumarin chemistry

AbstractPhoto‐responsive cellulose nanocrystal modified fluorinated polyacrylate was synthesized by environmentally friendly RAFT‐mediated Pickering emulsion polymerization using amphiphilic block copolymer modified cellulose nanocrystal poly(acrylic acid)‐g‐CNC‐g‐poly (hexafluorobutyl acrylate‐co‐7‐(2‐methacryloyloxyethoxy)‐4‐methylcoumarin) PAA‐g‐CNC‐g‐P (HFBA‐co‐CMA) (MCNC) as a stabilizer, and the photo‐responsive coumarin groups were introduced to endow it with self‐healing function. This paper mainly studied the effect of MCNC dosage on emulsion polymerization and latex film properties. The latex particle size and its distribution decreased as the MCNC dosage increased from 0.4 wt% to 1.0 wt%, and then increased afterwards. The mechanical property and thermal stability of latex films could be significantly improved by introducing MCNC. And the surface scratches of latex films with MCNC exceeding 0.4 wt% could be completely repaired after 7 h UV irradiation. Furthermore, the photo‐responsive cellulose nanocrystal modified fluorinated polyacrylate emulsion was applied to fabric finishing by dip‐rolling treatment. And the finished fabric had good hydrophobicity, oleophobicity and surface repair performance.

Stratified and gradient films by evaporation-induced stratification of bimodal latexes. Potential of confocal and scanning electron microscopy for compositional depth profiling

In the field of bimodal latex film's formation, finding methods to quantify particle concentration profiles within the film thickness is a challenge. Herein the advantages and limitations of confocal fluorescence microscopy (CFM) and scanning electron microscopy (SEM) are presented. Films are prepared from a bimodal fluorescent acrylic mixture of large non-deformable particles and small deformable particles having high Péclet numbers. A fixed volume fraction of large particles (ΦL) in the dispersion is used with increasing volume fractions of small particles latex (ΦS). At low ΦS, a surface stratification of large particles occurs with thicknesses up to several micrometers, allowing detection by both CFM and SEM. Small particles form a stratified surface layer above a threshold ΦS value. Its thickness of less than 500 nm is evidenced only by SEM due to the resolution limit of the confocal scan. SEM is also able to reveal concentration gradients of large particles below the “small-on-top” stratified layer.

Antioxidating and reinforcing effect of polydopamine functionalized silica on natural rubber latex films

AbstractSince the outbreak of COVID‐19, the demand for natural latex products with increased mechanical properties and aging resistance has surged. Based on the excellent adhesion and antioxidant properties of polydopamine (PDA), we employed a one‐pot method to modify the surface of silica substrates using PDA containing a polyphenol structure, to prepare a reinforced silica‐PDA composite latex material with antioxidant properties. As expected, the silica‐PDA composite achieved both uniform dispersion and good interfacial interactions with natural rubber latex (NRL). In addition, compared with common NRL/silica films, the mechanical properties of the NRL/silica‐PDA film were significantly improved; specifically, silica‐PDA can highly‐enhanced the mechanical property of NRL film from 24.94 to 32.18 MPa of tensile strength. Further, the antioxidant activity of the silica‐PDA film exceeded that of commercially available antioxidant D. Considering the notable performance boost of silica‐PDA composites on NRL films, we believe that the treatment of silica with natural polyphenols offers a convenient and facile new route for the preparation of environmentally friendly multifunctional silica additives.

Post-irradiation degradation of radio-oxidized natural rubber latex films induced by 60Co gamma rays

The present work involves the post-irradiation aging of radio-oxidized natural rubber latex (NRL) films irradiated by 60Co gamma rays. The NRL films underwent the two consecutive processes: irradiation oxidation in air with a dose of 0.1 kGy h−1 (pre-irradiation phase) and radiolysis in argon with a dose of 10 kGy h−1 (post-irradiation phase). The changes of oxygen-containing groups in radio-oxidized NRL films were subsequently analyzed by FTIR (ATR method), XPS, and Raman spectroscopy. Analysis of the EPR spectra of free radicals and macroscope properties (including mechanical and thermodynamic properties) were also carried out. Pre-irradiation of NRL films in air resulted in the rapid formation of various carbonyl and unsaturated carbonyl products related to aliphatic esters, ketones, and carboxylic acids. These were followed by the decomposition of the oxygen-containing functional groups in the post-irradiation phase. In particular, the formation of an enol tautomer of a β-diketone functionality was observed. The increase and decrease of free radicals by EPR analysis were closely related to the crosslinking and degradation of the NRL network structures induced by irradiation. Further analysis indicated that the variations in macroscopic properties of NRL films were attributed to the secondary reactions of free radicals. Mechanistic routes for these irradiation aging processes are proposed and discussed.

Optimisation for the synthesis of uniformly dispersed antimicrobial Ag/GO nanohybrid latex film

The combination of silver (Ag) nanoparticles (NPs) and graphene oxide (GO) nanosheets can be an advanced solution for an effective antimicrobial polymer film without agglomeration effect to reduce healthcare-associated infections. This study aims to develop an optimum formulation of Ag/GO nanohybrid latex film with the integration of antimicrobial property and mechanical reliability. A statistical approach using response surface methodology was employed to determine the optimum formulation. The concentrations of Ag/GO nanohybrid, A (0.0–1.0 wt%) and sulphur level, B (0–3 phr) were selected as the variables. Nine responses, killing ratio of E. coli, S. aureus, MRSA, K. pneumoniae, S. pyogenes, E. faecalis, E. faecium, tensile strength and puncture test were chosen to determine the optimum formulation. The optimised Ag/GO nanohybrid concentration and sulphur level are 1.21 wt% and 1.70 phr, respectively. These optimised variables are predicted to have killing ratios of 94.3367 %, 71.2997 %, 85.2221 %, 86.8940 %, 88.4657 %, 65.1685 % and 71.7915 % for E. coli, S. aureus, MRSA, S. pyogenes, K. pneumoniae, E. faecalis and E. faecium, respectively, together with tensile strength at 130.838 cm and puncture test at 91.0230 mm at 0.8862 desirability. No toxic effects and no sensitisation effects were detected on the skin applied with Ag/GO nanohybrid latex film.

Characteristics of latex coatings for steel protection against corrosion

This paper examines the kinetics of corrosion for steel St3 samples covered with a latex coating 69B–2k, manufactured by Kapitel LLC (Irkutsk), by analysing gravimetric tests performed using steel samples. A 3 wt % solution of sodium chloride was used as an electrolyte. The accuracy of the obtained results was confirmed by carrying out at least two parallel experiments. Prior to coating, the metal surface of samples was carefully prepared as per GOST R 9.907-2007. Film coatings were applied onto the metal surface by threefold dipping of samples in liquid latex followed by drying within 24 hours. The quality of the coating prior to and following the experiments was assessed visually and by microphotography. Gravimetric studies were carried out under temperature control (25 ± 0.2°C) in the working area. At the same time, changes in the sample mass were recorded over a controlled time interval (from 1 to 24 hours). The results of weighing samples obtained prior to and following the experiments were analysed using a kinetic flowchart, in which the type of reaction is defined in stages in a natural sequence. Kinetic analysis of the gravimetric results confirmed the absence of characteristic signs associated with chemical interactions on the surface of steel St3 coated with latex 69B-2k. Out of the known mathematical models of phenomenological kinetics, it is admissible to use a first-order equation to describe the course of a simple reaction during heterogeneous interaction, where the penetration of reagents through a latex film comprises a limiting stage. The kinetic analysis showed that it is necessary to study the properties of latex films; a strategy for further corrosion studies was determined.

PROPERTIES OF AMMONIA-FREE CONCENTRATED NR LATEX PRESERVED WITH N,N′-METHYLENEBISMORPHOLINE

ABSTRACT The NR latex (NRL) industry contributes to ammonia pollution, a problem that is difficult to solve. To address this issue, N,N-methylenebismorpholine (MBM) was used to prepare ammonia-free concentrated NRL (CNRL). The effect of MBM on the preservation and properties of CNRL was studied through comparison with high-ammonia (HA) CNRL. Results showed that MBM had an excellent preservation effect on ammonia-free CNRL. When the MBM dosage exceeded 0.35%, the volatile fatty acid value of CNRL was relatively stable and was consistently less than 0.06 over 180 days of storage. The prepared ammonia-free CNRL had lower viscosity and pH, and its mechanical stability test (MST) was moderate. The control results of the stabilization system showed that sodium dodecyl sulfate can significantly reduce the viscosity and improve the MST of the ammonia-free CNRL. KOH can significantly improve the pH and thermal stability of latex, but has little effect on improving MST. The ammonia-free CNRL had a lower pH after prevulcanization, but higher MST than the HA latex. The viscosity of the ammonia-free prevulcanized latex increased rapidly. The physico-mechanical properties of the vulcanizate films were slightly different from those of the HA latex samples. In addition, the infrared spectrum of the ammonia-free CNRL dry film was basically consistent with that of HA latex dry film. The thermal degradation curve and characteristic temperature of the ammonia-free CNRL dry film were basically the same as those of the HA-preserved film. Biosafety tests showed that the cytotoxicity of the MBM-preserved, ammonia-free CNRL dry film was slightly higher than that of the HA latex film. However, both films did not irritate the skin. All of these results illustrate that MBM has an excellent preservation effect on CNRL and the prepared ammonia-free CNRL has good processability, environmental protection, and safety.

Glycerol and Antimicrobial Peptide-Modified Natural Latex for Bacteriostasis of Skin Wounds.

This work aimed to develop a glycerol antimicrobial peptide natural latex film (NRL-GI-AMP film) for the treatment of skin wound infections. The contents of this work mainly include investigating the effect of adding glycerol (GI) and an antimicrobial peptide (AMP) on the physical and chemical properties of natural latex (NRL) and analyzing the cytocompatibility, bacteriostatic activity, and infected wound healing promotion of the NRL-GI-AMP film. The results showed that the addition of GI resulted in more pores in the internal structure of the NRL film, while the addition of G(LLKK)3L AMP did not change the structure and properties of the NRL film. Compared with that of the NRL film, the infrared spectrum of the NRL-GI-AMP film did not produce new characteristic peaks, indicating that GI and AMP were non-covalently cross-linked with NRL. Addition of 10% GI reduces the toughness of the NRL-GI-AMP film by 62.0%, increases the water vapor transmission rate by 8.95 mg/(cm2·h), and reduces the water absorption and water retention distributions by 33.0 and 24.7%, respectively. AMP in the NRL-GI-AMP film could be released continuously for 40 h, and the release rate was about 45%. The NRL-GI-AMP film showed good biocompatibility and antibacterial activity and promoted the healing of infected wounds. Therefore, the NRL-GI-AP film has potential application in the development of dressings to inhibit skin wound infection and promote wound healing.

Fabrication of dual-functional cellulose nanocrystals/fluorinated polyacrylate containing coumarin derivatives by RAFT-assisted Pickering emulsion polymerization for self-healing application

Polymeric coatings are easy to be damaged by harsh environment condition, which causes cracks and loss of function. Inspired by the natural self-healing phenomenon, we successfully synthesized dual-functional cellulose nanocrystals/fluorinated polyacrylate containing coumarin derivatives by RAFT-assisted Pickering emulsion polymerization. The amphiphilic and photo-responsive copolymer, PDMAEMA-b-PGMA-b-P(HFBA-co-VBMC) was synthesized by RAFT process, followed by characterization using FT-IR, SEC, 1H NMR and UV–vis. The cellulose nanocrystals were modified by the copolymer, which were confirmed via XPS, UV–vis and so on. Besides, the droplet size of Pickering emulsion gradually increased and the creaming layer gradually decreased as the pH value increased. The TEM result showed that the modified cellulose nanocrystals were effectively anchored on the outside of latex particles. The size of the spherical-like latex particles increased and the stability of latex particles was worse with increasing pH value. Finally, the finished fabric had excellent water resistance due to the combination of micro- or nanoscale hierarchical structure and low surface energy. Moreover, the latex film exhibited excellent repeatability of self-healing ability. The fabric coating achieved the intrinsic and superficial dual-functional self-healing performance by the reversible [2 + 2] cycloaddition of coumarin groups. This strategy provides a powerful guide for preparing the high-performance waterborne fluorinated polyacrylate coating.

Euphorbia tirucalli latex loaded polymer nanoparticles: Synthesis, characterization, in vitro release and in vivo antinociceptive action.

The encapsulation of drugs in micro and nanocarriers has helped to resolve mechanisms of cellular resistance and decrease drug side effects as well. In this study, poly(D,L-lactide-co-glycolide) (PLGA) was used to encapsulate the Euphol active substance-containing latex from Euphorbia tirucalli (E-latex). The nanoparticles (NP) were prepared using the solvent evaporation method and the physical and chemical properties were evaluated using spectrophotometric techniques. FTIR was used to prove the formation of the ester bond between the E-latex and PLGA-NP. The UV-Vis spectroscopic technique was used to show that more than 75% of the latex was encapsulated; the same technique was used to determine the release profile of the compound at different pH values, as well as determining the speed with which the process occurs through kinetic models, and it was observed that the best adjustments occurred for the Korsmeyer-Peppas model and the Higuchi model. The DLS technique was used to determine the diameter of the particles produced as well as their zeta potential (ZP). The sizes of the particles varied from 497 to 764 nm, and it was observed that the increase in E-latex concentration causes a reduction in the diameter of the NP and an increase in the ZP (-1.44 to -22.7 mV), due to more functional groups from latex film being adsorbed to the NPs surfaces. The thermogravimetric experiments exhibit the glass transition temperatures (Tg) that is appropriate for the use of formulated NPs as a stable drug delivery device before use. The in vivo activity of E-NPs (30 and 100 mg/Kg/p.o.) was tested against carrageenan-induced mechanical hypernociception. The data demonstrated a significantly antinociceptive effect for E-NPs, suggesting that E-latex nanoencapsulation preserved its desired properties.

Natural fluorescent red colorants produced by Talaromyces amestolkiae as promising coloring agents for custom-made latex gloves

Synthetic-based colorants have been extensively used in several industries, viz., cosmeceutical, feed, pharmaceuticals, food and textile. However, the growing awareness of potential teratogenicity, carcinogenicity and environmental concerns of certain synthetic colorants have expressed several limitations regarding their use in some products. These limitations, justifies the motivation to look for eco-friendly alternatives (cf., natural colorants) to be used as coloring agents for industrial applications. The filamentous fungi Talaromyces amestolkiae appeared as a promising source of natural fluorescent red colorant (NFRC) for the development of custom-made latex gloves. In this study, some basic colorant properties, including 3D-fluorescence and CIELAB color characteristics were first investigated systematically before their incorporation in natural rubber latex (NRL) films. The NFRC-NRL films properties were evaluated by physicochemical tests and toxicity through cell viability using 3T3 fibroblasts, wherein eluate of NFRC-NRL films (2.28 AU) revealed viability >70 % (exposing the biocompatibility). Regardless of the strategy proposed, it is shown as a proof-of-concept the potential application of NFRC in the NRL matrix as a biocompatible alternative to produce sustainable commercial colored custom-made latex gloves.

Design of epoxidized natural rubber/poly(lipoic acid) elastomer with fast and efficient self-healing under a mild temperature

Most of the dynamic covalent bonds (DCBs) for self-healing rubber must be activated at relatively high temperatures due to the requirement of high energy during the exchange of dynamic bonds, which may lead to unexpected degradation or excessive crosslinking of rubber. Herein, we designed and fabricated a highly stretchable, self-healable and reprocessable rubber by introducing dynamic disulfide bonds into the crosslink network of epoxidized natural rubber (ENR). Lipoic acid (LA) was firstly uniformly dispersed into ENR via a latex film formation technique, and then underwent a dynamic covalent ring-opening self-polymerization during hot pressing process, during which the carboxyl group of poly(LA) attacked the epoxy group of ENR to form β-hydroxyl ester bond crosslinks. As a result, a revisable covalently crosslinked network without rigid steric hindrance groups was constructed, which exhibited a super self-healing efficiency of 99 % after self-healing at 80 °C for only 3 h. The elongation at break of the elastomer could reach 1115 % and the recovery rate of reprocessing was as high as 91 %.

Modified natural rubber latex film-forming enhances bamboo scraps/magnesium oxychloride composites

Bamboo scraps/magnesium oxychloride composites are new low carbon and environmentally friendly building materials. Its development not only reduces carbon dioxide emissions, but the use of bamboo scraps can improve bamboo utilization rates and play important roles in protecting the environment. However, in some environments, water resistance is problematic and mechanical strength decreases, thereby seriously affecting applications in architectural settings. Natural rubber latex (NRL) can be coated after dehydration and film forming, and modified by surfactants to improve cement properties. In this study, natural rubber latex modified by sodium dodecyl sulfate (S-NRL), was used as a modifier to improve bamboo scraps/magnesium oxychloridee composite properties. The results showed that after S-NRL addition, latex films formed by water loss not only filled voids in bamboo scraps/magnesium oxychloride composites, but also generated surface negative charges. These were adsorbed by magnesium (Mg2+) ions, at strength phase-5, and formed surface waterproof protective films to prevent water erosion. Thus, composite mechanical and water resistance properties were enhanced; when S-NRL was at 0.3%, mechanical strength and water resistance properties were at a maximum after curing for 28 days.

Carboxylated acrylonitrile butadiene-natural rubber latex blends with methyl methacrylate grafted natural rubber latex: mechanical properties and morphology.

Commercially available carboxylated acrylonitrile butadiene latex (XNBR) was physically blended with natural rubber latex (NR) at varying blend ratios to investigate its effect on the mechanical properties and morphology. Methyl methacrylate grafted natural rubber latex (MG) was added to the latex blends as a third polymer to study whether it could enhance the mechanical properties of the latex blend films. It was found that the tensile strength of the blend films irrespective of composition decreased when the two latexes were blended as compared to the virgin latex films. The modulus 300 decreased while the elongation at break and tear strength of the blend films increased gradually as the ratio of NR increased in the blend films. It was found that the MG did not enhance the mechanical properties of the XNBR/NR blend films under the current experimental condition. AFM phase imaging analysis revealed enhanced polymer distribution and evidence of NR-MG-XNBR interactions.