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Green thermoplastic starch (TPS) nanocomposite films aided by cellulose nanofibers (CNFs) from Chrysopogon zizanioides roots were developed and characterized. When compared to other lignocellulosic fibers, Chrysopogon zizanioides roots revealed exceptionally high cellulose content (~48%). CNFs were separated using an environmentally friendly acid isolation technique that included three stages: (i) alkali treatment; (ii) bleaching; and (iii) mild acid hydrolysis using oxalic acid in an autoclave. Following that, green nanocomposite films were made from potato starch using the solution casting process, by which we used glycerol (30 wt%) to make thermoplastic starch. Then, cellulose nanofibers in different concentrations (0, 1, 2, 3, 4 wt%) were added to the thermoplastic starch matrix. The isolated CNFs had diameters in the range of 17–27 nm. Besides, these nanostructures presented a very high crystallinity index (~65%), thereby enhanced the thermal stability. TPS/CNF green nanocomposites containing 3 wt% CNFs had exceptional tensile strength (~161%), tensile modulus (~167%), thermal stability, and crystallinity. As a result, nanocomposite films made of starch and cellulose nanofibers (3 wt%) extracted from Chrysopogon zizanioides roots would be alternatives for sustainable packaging. It can be concluded that Chrysopogon zizanioides roots have high potential for polymer industry.

Infections caused by the biofilm-forming multi-drug resistant organisms are increasing day by day. In this study, polyvinyl alcohol (PVA) based antimicrobial membranes were developed with the incorporation of lipopeptides (LPs) and zinc oxide nanoparticles (ZnONPs) by solvent casting method. The fabricated membranes were further characterised by the FT-IR, SEM, UV–vis spectroscopy, TGA and mechanical analysis. The results showed enhanced optical, thermal, mechanical and water barrier properties for the membranes engineered with LPs and ZnONPs. The membranes also showed excellent activity against the biofilm-forming bacteria such as the Staphylococcus aureus, Klebsiella pneumoniae and Pseudomonas aeruginosa. Also, the developed nanocomposite membranes were found to be hemocompatible with enhanced dressing pH features. Hence, the developed nanocomposite membranes can be considered to have promising biomedical application as antimicrobial coating.

The use of chicken feather short fiber (CFF) as filler for polymer offers an ecofriendly method for the development of composites and coatings. In the present study, CFF filled epoxy coating has been developed to protect carbon steel from corrosion. The morphology of the coating surfaces was investigated using optical microscopy (OM) and atomic force microscopy (AFM). The surface properties such as wettability and surface roughness were determined. The corrosion studies on the coatings were evaluated using an accelerated salt immersion test. This green approach for the development of epoxy/CFF coating offers protection of metal parts used in many modern industries from the corrosive environment, improve the performance and ensure safety.

Designing environmentally friendly materials from natural resources represents a great challenge in the last decade. However, the lack of fundamental knowledge in the processing of the raw materials to fabricate the composites structure is still a major challenge for potential applications. Natural fibers extracted from plants are receiving more attention from researchers, scientists and academics due to their use in polymer composites and also their environmentally friendly nature and sustainability. The natural fiber features depend on the preparation and processing of the fibers. Natural plant fibers are extracted either by mechanical retting, dew retting and/or water retting processes. The natural fibers characteristics could be improved by suitable chemicals and surface treatments. This survey proposes a detailed review of the different types of retting processes, chemical and surface treatments and characterization techniques for natural fibers. We summarize major findings from the literature and the treatment effects on the properties of the natural fibers are being highlighted.

The aim of this study is to investigate natural cellulosic fibers extracted from Tridax procumbens plants. The obtained fibers were alkali treated for their effective usage as reinforcement in composites. The physical, chemical, crystallinity, thermal, wettability and surface characteristics were analyzed for raw, and alkali treated Tridax procumbens fibers (TPFs). The test results conclude that there was an increase in cellulose content with a reduction in hemicellulose, lignin, and wax upon alkali treatment. This enhanced the thermal stability, tensile strength, crystallinity, and surface roughness characteristics. The contact angle was also lesser for treated TPFs which prove its better wettability with the liquid phase. The Weibull distribution analysis was adopted for the analysis of the fiber diameter and tensile properties. Thus the considerable improvement in the properties of alkali treated TPFs would be worth for developing high-performance polymer composites.

Self-healing materials attract enormous scientific attention as they offer wide range of applications in conjunction with long-lasting performance. Self-healable polymers find potential candidates for construction materials, automotive parts, electrical encapsulation, adhesives, coatings, etc. Due to the lightweight, high thermo-mechanical performance, excellent adhesion, gloss, good chemical resistance, and corrosion resistance, epoxy resins are preferred over other polymers for coating applications. Although epoxy resin coatings are widely used in commercial vehicles and high compact aircraft, their susceptibility toward scratches and microcracks is a major concern. Such failures may be addressed by making use of self-healing epoxy coatings. In this review, we focus on inhibitor and polymeric healing agents encapsulated in organic and inorganic containers for the self-healing epoxy coating. The different organic and inorganic containers such as micro/nano polymer capsules, cellulose nanofibers, halloysite nanotubes, titanium dioxide nanocontainers, mesoporous silica, hollow glass fibers, and core–shell nanofibers have been utilized as reservoirs to store the self-healing agents. In addition, self-healing techniques such as layer-by-layer method, microvascular networks, ion exchange method, reversible crosslinks, and shape memory assisted self-healing are reviewed.

In the study, the effectiveness of lipopeptide containing nanocomposite film has been investigated for food packaging applications against the spoilage organisms and foodborne pathogens. Here, polyvinyl alcohol (PVOH) films incorporated with clay nanoparticles (C) and lipopeptides (L) were prepared by solvent casting. The prepared films were further characterized by Fourier transform-infrared spectroscopy, universal testing machine, and scanning electron microscopy. From the results, the lipopeptides and clay nanoparticles incorporated PVOH nanocomposite film (PNF) was found to have enhanced mechanical and barrier properties when compared with the neat PVOH film. The thickness, tensile strength, Young’s modulus, elongation at break, and water absorption capacity of the PNF film were 0.170 ± 0.008 mm, 34.4 ± 1.8 MPa, 1.4 ± 0.3 GPa, 82 ± 2 %, and 94.92 %, respectively. The PNF film developed in the study was found to inhibit the growth of foodborne pathogen Salmonella typhimurium and also the spoilage causing Pythium myriotylum. From the results, the films engineered with the lipopeptides and clay nanoparticles can be considered to have application as active food packaging wraps for the protection and preservation of food products.

Graphene nanoplatelet derived from human nail was synthesized through a novel synthetic in-situ methodology by using ferric chloride. XPS was performed to scrutinize defects and the percentage of saturated and unsaturated bonds of carbon. Pseudo second order kinetic equation vividly described the nature of the sorption of As(III) on GN surface. Response surface methodology and analysis of variance were used to optimize the reaction parameters. The Langmuir isotherm equation explicitly demonstrated layer dependant sorption phenomenon. The sorption efficiency by GN at lower As (III) concentration range, was observed to be ~99% (247.22 mmol.kg−1) at 300 K, whereas the sorption reaction was endothermic (ΔH0 = +15.09 kJ mol−1) as well as spontaneous (ΔG0 = −0.90 to −3.16 kJ mol−1, and the positive entropy (ΔS0 = +0.05 kJ mol−1K−1) at interface was the driving force of the adsorption reaction.

Numerous studies have been carried out globally to develop polymer coatings that could protect the underlying metal substrates from corrosion. Among these approaches, self-healing bio-based epoxy coating plays a promising role in corrosion protection. In the present study, a dual container self-healing coating system was developed from bio-based epoxy resin, halloysite nanotubes and silica nanoparticles. The halloysite nanotubes (HNTs) were filled with bio-based epoxy resin by vacuum infiltration technique and the silica nanoparticles were modified with a UV initiator by simple mixing. Later the filled halloysite nanotubes and modified silica nanoparticles were mixed with pure bio-based epoxy resin and hardener and cured to obtain self-healing composites. During the scratch/damage of the epoxy coating, the halloysite nanotube ruptures and the bio-based epoxy resin stored inside the nanotube fills the scratch and comes in contact with UV initiator immobilised on the silica nanoparticles, initiating the curing reaction. At 40 wt% of encapsulated HNTs, the scratch on the bio-based epoxy surface is found to undergo complete self-healing in the presence of sunlight. Overall, the composites showed an increased UV-shielding ability, improved thermal stability, and good transparency. Therefore, the developed bio-based epoxy composite is a viable self-healing coating for metals.

In this paper, we report on the effect of amphiphilic poly(ethylene oxide)-poly(propylene oxide)poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymer (TBCP) on the miscibility, phase separation, thermomechanical properties and surface hydrophobicity of diglycidyl ether of bisphenol-A (DGEBA)/4,4'-diaminodiphenylmethane (DDM) system. The blends were nanostructured. The phase separation occurred via self-assembly of PPO blocks followed by the reaction induced phase separation of PEO blocks. The surface roughness increased with increase in concentration of TBCP due to increased phase separation of PEO blocks at higher concentration. The phase separated PEO blocks formed the crystalline phase in the amorphous crosslinked epoxy matrix. The TBCP has a strong plasticizing effect on the matrix and decreased the glass transition temperature (T-g) and modulus of the thermoset. The incorporation of TBCP improved impact strength and tensile properties and 5 phr TBCP content was found to be optimum to achieve balanced mechanical performance. Moreover, the thermal stability of the epoxy system was retained while hydrophobicity was improved in the presence of TBCP. (C) 2017 Elsevier Ltd. All rights reserved.

We made an attempt to produce low cost carbon fibers using textile grade polyacrylonitrile (Tex-PAN) fibers. Here, we examined fibers collected from each zone of the stabilization and carbonization furnaces and mechanical and physical properties were measured with the aim to evaluate their chemical stability and final properties. Thermal studies revealed a cyclization peak at 308 °C and an extent of reaction of 66.2% after stabilization process. The apparent crystallite size after carbonization was determined by X-ray diffraction and it was found to be smaller in Tex-PAN fibers than commercial PAN fibers. Raman spectroscopy confirmed the development of the graphitic structures within the carbon fibers produced from Tex-PAN. Interestingly, the tensile properties (3.25 GPa) of carbon fibers from Tex-PAN fibers were found to be comparable with those of commercial PAN fibers. Precursor fibers take more than half of total production cost for producing carbon fibers (CFs), Tex-PAN precursor can be an indispensable candidate for low cost CF production.

As one of the goals in recent research and development is to use eco-friendly materials from sustainable resources to manufacture a product material. Bioepoxy resin is a relevant choice to maximize the natural content of the composites along with natural fiber as a reinforcement material. This work presents the effect of poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) triblock copolymer in bioepoxy and bioepoxy composites prepared by sisal fibers. Incorporation of the triblock copolymer in bioepoxy resin enhances the tensile, flexural, and impact properties. The viscoelastic properties show good plasticization of the triblock copolymer with the bioepoxy matrix. The contact angle increases in the presence of the triblock copolymer, while the water absorption is marginally decreased. To the best of our knowledge, the modification of poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) triblock copolymer with bioepoxy resin has not been reported to date. Further poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) triblock copolymer was used as a modifier for sisal fiber fabrics-reinforced polymer composites. The tensile, flexural, and impact properties improve to some extent.

Three-dimensional graphene architectures were synthesized from a new source, chicken feather, a bio-waste. Here ferric chloride (FeCl3) was used as a self-originator template, with a high C/O ratio (21:1). The introduction of Fe3＋ ion into the activated frame of carbon generated graphene nanostructure. X-ray photoelectron spectroscopy was used to analyse the defects in the prepared graphene. The obtained structures were found to be unique nanoplatelets and three-dimensional pyramid-like structure. Its DC conductivity has been tested within the temperature range of 20 to 300K and their temperature-dependent conduction mechanism was established. At ∼ 100 K and ∼ 50 K, a 3D–2D and Mott–ES type cross-over were observed respectively, with varied hopping length. The conductivity was found to be decreased with lowering temperature which was similarly observed in metals.

Zeolite are porous material with high surface area and adsorption capacity. It has been employed for the removal of organic contaminants from aqueous system. Here, we report the synthesis of mesoporous ZSM-5 zeolite using a bio template, cellulose. The adsorbent was investigated in detail by different characterization techniques such as Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption, thermogravimetric analysis (TGA) and 27Al nuclear magnetic resonance (NMR) analysis. The crystalline and MFI nature of the mesoporous ZSM-5 zeolite was confirmed by XRD and FTIR analysis. N2 adsorption/desorption result showed that mesoporous ZSM-5 zeolite has high surface area and pore diameter which was later confirmed through morphological characterization such as SEM and TEM. The adsorption ability of the mesoporous ZSM-5 zeolite was evaluated using methyl orange (MO), an anionic azo dye. The effect of initial dye concentration, adsorbent amount, contact time, temperature and pH on the MO removal process was reviewed. The percentage removal of mesoporous ZSM-5 zeolite is 94.3 % which is much higher than that of the conventional ZSM-5 zeolite (73.2 %). Adsorption isotherm studies were interpreted using two different models i.e., Langmuir and Freundlich model. The result indicates that the adsorption could be well described by Freundlich isotherm model. Meanwhile, kinetic data were best described by pseudo-second-order model. The recyclability test suggest that the synthesized adsorbent has superior regeneration capacity and is stable even after eight adsorption-desorption cycle. Thus, our results show that mesoporous ZSM-5 zeolite is a promising competitor for the removal of dye from aqueous medium.

This review provides a comprehensive analysis of available peer-reviewed literature in which graphene and/or its derivatives are incorporated into a polymer matrix in order to enhance the final properties and functionalities of the three dimensional (3D) printed structure. Research in which graphene derivatives have been incorporated into plastic 3D printing technologies such as Fused deposition modeling (FDM), Stereolithography (SLA), Selective laser sintering, Inkjet 3D printing, Extrusion-based printing and Binder-jet printing is presented. For certain design requirements and applicability of the material, great care needs to be taken to select the appropriate printing method. Factors which play a key role in final performance of the printed parts are identified, including dispersion of graphene or its derivatives in matrix, interfacial interaction between graphene or its derivatives and matrix, printing orientation, nanofiller's aspect ratio, reduction of graphene oxide and ink viscosity. In fact, the multifunctional applications of the 3D printed structures based on graphene or graphitic filler composites open up the countless possibilities of current research. Although great progress has been made in exploring the mechanical, electrical, optical and thermal, characteristics of these materials, significant research and development need to be done to fully fetch their inherent potential. This article serves the purpose to researchers to improve latest research outcomes and explore new graphene–based nanocomposites for different applications.

This article presents a comprehensive review on the recent development of graphene and its derivatives in the design and engineering of smart sensors, actuators and soft robotics. Comparing with traditional materials used in the fabrication of sensors and actuators, graphene and its derivatives obviously improved the sensitivity and selectivity of the devices due to their unique properties stemmed from graphene. In this article, we summarized mechanisms, design and engineering, and development of different graphene-based sensors actuators and soft robotics. We also selectively discussed on different techniques and methodologies to improve the performance of graphene-based sensors actuators and soft robotics, especially sensitivity and selectivity. To yield significant improvement and extend the field of applications, scientists have to improve the production of high-quality graphene, enhance the interface and interaction between graphene and other materials, develop multi-functional sensors or actuators, and finally achieve industrial production. Finally, the current challenges, prospective and potential soft robot application of various graphene-based sensors and actuators have been highlighted in detail.

Food packaging generates a large volume of waste materials and >90% of the waste plastics are landfilled. The growing demand for high quality and safe packaging materials have resulted in the longer shelf life of foods packed with eco-friendly materials. This needs natural base materials for packaging applications, along with active ingredients that can extend the shelf life of the food materials. One such development in the field of active packaging is antimicrobial packaging. Out of the many antimicrobial agents used, the essential oils (EO) are gaining more importance especially due to their high activity. This review aims to give an insight into the developments in active food packaging, especially with EO. Various biopolymer containing EO have been used for food packaging applications. An insight into the recent approaches used for the casting of biopolymer films with EO is given. The effect of EO on the physical properties of the biopolymer films, the migration and release of the active agents on to the food surface, and the mechanism of action have been highlighted. The challenges and opportunities of EO for the food packaging industry have been discussed.

Epoxy resin/4,4′-diaminodiphenylsulfone (DDS) system was modified by the incorporation of poly(e-caprolactone)-block-poly(dimethyl siloxane)-block-poly(e-caprolactone) (PCL–PDMS–PCL) triblock copolymer (TBCP). Morphology, viscoelasticity, thermo-mechanical and surface properties of these blends were investigated. All the blends were opaque after curing. PCL blocks of the TBCP were miscible with epoxy resin while the PDMS fraction was immiscible. However in the cured state, both PCL and PDMS blocks were phase separated from epoxy/DDS matrix. The blends exhibited matrix-droplet morphology in which TBCP phase dispersed as spherical domains in epoxy matrix. Addition of TBCP had profound impact on the cure reaction kinetics. Storage modulus and glass transition temperature (Tg) decreased while impact strength significantly increased. Incorporation of 15 phr of TBCP resulted in 80% improvement in impact strength. Further, thermal stability was unaffected while surface hydrophobicity of the blends increased.

Mechanical and physical properties of polypropylene (PP)/polystyrene (PS) blend, PP/PS/polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (SEBS) ternary blend and their composites with carbon nanofibers (CNF) were investigated. Composites of ternary blend exhibited superior properties compared to those of binary blends. Mechanical performance of nanocomposites was intimately related to their phase morphology. PP/PS/SEBS/0.1 wt% CNF hybrid composites exhibited excellent impact strength (Four-fold increase compared to PP/PS blend) and ductility (12-fold increase in elongation at break, with respect to PP/PS blend). Moreover, these composites displayed good tensile strength and modulus (15% increase in Young's modulus, compared to PP/PS/SEBS blend) and are suitable for various end-use applications including automobile applications. Although crystallinity of PP phase is decreased by the incorporation of CNF, thermal stability of the composites remained almost unaffected. Contact angle measurements revealed that ternary composites exhibited maximum hydrophobicity.

In this work novel poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) polymer composites were prepared by incorporating Ceiba pentandra bark fibers. The casting technique was used for the preparation of the composites. The effect of Ceiba pentandra bark fibers on the morphology, thermo-mechanical, hydrophilicity, transparency, biodegradability, antimicrobial, and packaging properties were studied. The scanning electron microscope was used for morphological characterization while Fourier transform infrared spectroscopy was used for structural analysis. The investigation was done on the mechanical properties, percentage crystallinity, and biodegradability of these composites. It was found that the incorporation of fibers enhanced the tensile properties, percentage crystallinity, and the biodegradability of the composite when compared to that of the virgin PHBV. Additionally, all the biocomposites show good thermal stability. Antimicrobial studies showed that the composite films of higher fiber loading showed antibacterial activity against S.aureus while no activity was shown against E. coli. Finally, these composite films were used for packaging of fresh strawberries which showed that the strawberries packed in films of fiber loading above 10 % have better preservation of freshness of the fruit than unpacked strawberries which showed mold attack after 7 days of packing.

For the first time, unique microsphere of ruthenium manganate was prepared by the sol-gel assisted xerogel sintering methodology. X-ray diffraction results showed that the materials were comprised of a distinctive tetragonal structure with a cell volume of 323 (A3). Ru4+ has successfully combined with the Mn2+ to form the compact lattices. The interatomic distances and angles of the three corresponding neighboring atoms were calculated with their preferred unit cell structure. SEM and TEM study confirmed the development of solid microsphere. Energy dispersive X-ray analysis showed elemental percentage on materials surface. X-ray photoelectron spectroscopy demonstrated the quantified oxidation states of the elements. Magnetic measurements performed in the temperature range of 10 K–300 K indicated that the sample showed predominantly superparamagnetic character at room temperature.

Carbon-based nanomaterials such as carbon nanotubes (CNTs) have become the most promising materials in biomedical, electronic and aerospace applications. When added to polymers, they can enhance the properties and the utility of the polymers to a large extent. This is because of their superior thermo-mechanical and electrical properties which can be effectively transferred to the resulting composites with their proper dispersion in the polymer matrix. But the uniform dispersion of CNTs in various polymer matrices is the major challenge faced by scientists. This paper critically reviews the different chemical strategies adopted for grafting polymers onto the CNTs which ultimately leads to better polymer-filler interaction and optimum filler dispersion for the development of high-performance polymer nanocomposites. This review also discusses the synthesis, properties, and applications of polymer grafted CNTs and their composites.

Nickel manganate nanorod (NNM) decorated reduced graphene oxide (NNMG) was developed and its structure-property correlations in light of X-ray diffraction (XRD), Raman, field emission-scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) were evaluated. The starring role of NNM and reduced graphene oxide (RGO) in NNMG for CO sensing was explored and an insight into the mechanistic pathway of sensing was proposed. NNMG displayed an excellent response % (∼ 7000) and sensitivity (0.60 ppm−1), which can surpass most stable efficient sensors, indicative of the synergistic effect of RGO and NNM. Moreover, NNMG can competently sense CO gas at wide range of concentration (25–200 ppm) with good stability and reversibility. Ligand like approach of CO facilitated donation of electron to the lattice oxygen vacancy and subsequently decrease electron barrier at the Schottky junction, resulting the higher response. The obtained outcomes demonstrated that the rational design of nanorod decorated RGO could be a promising strategy to improve CO sensing performance.

The reduction of the environmental impact from renewable resources can provide an interesting sustainable platform. Natural fiber is an outstanding renewable resource for making composite materials for lightweight applications. However, the major disadvantage of natural fiber as reinforcement material in composites is their hydrophilic nature. The present investigation is an attempt to develop kenaf/sisal fiber fabric reinforced bioepoxy hybrid composites and assess the performance of the composites under accelerated weathering conditions. To the best of our knowledge as of now there is no work has been published in this concept. The bioepoxy resin and kenaf/sisal fiber fabrics were used for making hybrid bio-based composites and manufactured composite laminates using a compression molding method. For comparison purpose, a neat bioepoxy thermoset was fabricated by casting mold technique. To promote the accelerated weathering of composites, the samples were exposed to environmental conditions such as ultraviolet radiation, extreme temperature and humidity conditions in accelerated weathering tester machine according to ASTM G155-13 cycle 1. The tensile, impact, morphology, thermogravimetric analysis, dynamic mechanical analysis, and water absorption test were performed for both before and after weathering test samples according to international standards. The results indicated that the manufactured fully bio-based kenaf/sisal fiber reinforced hybrid bioepoxy composites showed moderate properties when compared to the neat bioepoxy composite at both before and after weathering conditions. From the results, it is worth to point out that these fully bio-based composites are promising composite material for semi-structural applications.

Epoxy resin was modified by the incorporation of poly (e-caprolactone)-block-poly (dimethyl siloxane)-block-poly (e-caprolactone) (PCL–PDMS–PCL) triblock copolymer (TBCP) in the presence of 4,4′-diaminodiphenylmethane (DDM). The role of intermolecular hydrogen bonding interaction in cure behavior, morphology, thermo-mechanical and surface wetting properties of TBCP modified epoxy thermoset was investigated. Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), atomic force microscopy (AFM), scanning electron microscopy (SEM), universal testing machine (UTM), thermogravimetric analysis (TGA) and contact angle measurements were used to characterize the samples. It is observed that PCL blocks of the TBCP were miscible with epoxy phase while the PDMS blocks remain immiscible. The miscibility of TBCP was analyzed and confirmed by FTIR and DSC, however, nanoscale inhomogeneities with ca. 20 nm were observed while examining AFM images. Addition of TBCP decreased the crosslink density between the polymers and therefore reduced the glass transition temperature (Tg), signifying the interpenetration of PCL blocks into the epoxy matrix. All the prepared blends showed shape memory effect. TBCP was very effective in improving the mechanical properties of epoxy matrix. Incorporation of 5 phr of TBCP improved the tensile strength, tensile elongation and tensile toughness by ca 20%, 55% and 90%, respectively. The thermal stability and water contact angle remained unaffected with the addition of TBCP.

Nanocomposites of polypropylene (PP) and polypropylene/styrene-(ethylene-co-butylene)-styrene triblock copolymer (SEBS) blends with exfoliated graphene nanoplatelets (xGnP) were prepared by melt-mixing method. The incorporation of xGnP increased the stiffness and crystallinity of PP at the expense of toughness and the molecular mobility. The effect of addition of SEBS on the mechanical, viscoelastic, thermal degradation and crystallization properties of PP/xGnP composites was studied. The addition of SEBS into PP transformed the phase structure and distribution of xGnP in the PP matrix. SEM micrographs revealed that SEBS polymer chains formed a coating over the graphene nanoplatelets, which strengthened the interface between the filler and the matrix, and improved the dispersion and distribution of the filler throughout the matrix.

Blends of polyamide12 (PA12) and isotactic polypropylene (PP) were prepared by melt mixing, in an internal mixer, in the presence and absence of compatibiliser. The compatibiliser used was maleic anhydride grafted PP (PP-g-MA). The dynamic mechanical properties of the blends with and without compatibiliser were studied. Although compatibilization shifted the glass transition temperatures (Tg's) of component polymers only marginally, it significantly enhanced the storage modulus of the blends. The storage moduli of the uncompatibilised blends were compared with those predicted by theoretical models. Correlation between the dynamic mechanical properties of both compatibilised and uncompatibilised blends and their phase morphology was made.

The formation of rare flower like micelles in poly(styrene)-block-poly(4-vinyl pyridine)/poly(acrylic acid) (PS-b-P4VP/PAA) diblock copolymer/homopolymer complexes is reported. The self-assembly as well as the morphological changes in the complexes were induced by the addition of a high molecular weight PAA/ethanol solution into the PS-b-P4VP solution in dimethyl formamide followed by dialyses. The composition-dependent micelles were varying in size and shape with increase in PAA concentration in solution. The complex aggregates in solution were characterized by dynamic light scattering (DLS) whereas morphologies in the solid complexes were observed using transmission electron microscopy (TEM). Flower like micelles are formed in complexes at 20 wt% PAA concentration followed by ‘spikey’ micellar assemblies at 40 wt% PAA. The size of the micelles was found to be increased upon the addition of PAA into the block copolymer solution. Infrared studies revealed the intermolecular hydrogen bonding interactions between the complementary binding sites on PAA and the P4VP block of the block copolymer. Finally, a model was proposed to explain the self-assembly and morphological transitions in these complexes based on the experimental results obtained.

The polylactic acid is modified with porous silica-containing varying amount of capsicum oleoresin. The effect of accelerated weathering on the polymer degradation, thermomechanical, antibacterial, and rheological properties was studied. The accelerated weathering test was performed for 260 and 520h. The prepared composites show antimicrobial activity against gram-positive and gram-negative bacteria. The tensile strength, modulus, and percentage crystallinity of the composites increased by 17, 7, and 33% respectively with the addition of 1.54 wt% of capsicum oleoresin impregnated porous silica. On the other hand, the incorporation of capsicum oleoresin impregnated porous silica reduced shear modulus and shear viscosity of the composite films. The accelerated weathering, reduced tensile properties, thermal stability, and rheological properties; however, the percentage crystallinity was increased due to the chain scission of the polymer chains. The combination of ultraviolet irradiation, temperature, and humidity caused by the weathering test marginally reduced the antibacterial properties of the polymer films.

Bionanocomposites are promising green sustainable materials useful for diagnostic and biomedical applications. In the present study, cellulose/copper nanoparticles (CuNP) bionanocomposites were prepared using a bioflocculant as a reductant of the precursor copper ions for the in situ generation of CuNP in the cellulose matrix.. The novel bionanocomposite material was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), antibacterial and corrosion tests. TEM, SEM, EDS, and XRD studies indicated the in situ generation of CuNP in the cellulose matrix. FTIR analysis proved no new bond formation between CuNP and cellulose films. Thermogravimetric analysis indicated single step degradation for neat cellulose whereas the bionanocomposites exhibit multi-step thermal degradation. The new bionanocomposite prepared with a copper precursor concentration of 250 mM was found to exhibit remarkable biocidal activity against E. coli with a zone of clearance of 12 mm and also good corrosion resistance.