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The effective utilization of bio-based material, epoxidised soybean oil (ESO), in recycled blend of Poly(vinyl chloride)/Poly(methyl methacrylate) (PVC/PMMA) was considered for the first time in this present investigation. Recycled blend with different concentrations of ESO were prepared via melt blending technique. Resulted blends were characterized by various physiochemical, mechanical and thermal characterizations. Fourier transform infrared (FTIR) analysis indicates reduction in the degradation behaviour of PVC phase present in the PVC/PMMA blend after introduction of ESO into it. The recycled blend with 9 wt% of ESO exhibit superior impact strength than other compositions. The thermal gravimetric analysis of ESO incorporated blend shows improved thermal stability than its parent blend. The DSC analysis shows improved compatibility of recycled blends in presence of ESO. Moreover the scanning electron microscope (SEM) analysis exhibits improved surface morphology with enhanced interfacial adhesion. Thus this study paves way for exploitation of bio derived ESO for value addition of recycled plastics from waste electrical and electronic equipments.

We address the mechanism of early stages of growth and shape transition of the unique nanowall network (NwN) nanostructure of GaN by experimentally monitoring its controlled growth using PA-MBE and complementing it by \textit{first-principles} calculations. Using electron microscopy, we observe the formation of tetrahedron shaped (3 faced pyramid) islands at early stages of growth, which later grows anisotropically along their edges of the (20$\overline{2}$1) facets, to form the wall like structure. The mechanism of this crystal growth is discussed in light of surface free energies of the different surfaces, adsorption energy and diffusion barrier of Ga ad-atoms on the (20$\overline{2}$1) facets. By \textit{first-principles} calculations, we find that the diffusion barrier of ad-atoms decreases with decreasing width of facets, and is responsible for the anisotropic growth and formation of the nanowall network. This study suggest that formation of NwN is a archetype example of structure dependent attachment kinetic (SDAK) instability induced shape transition in thin film growth.

Polymer electrolyte membranes (PEMs) of sulfonated polysulfone (SPSf) and sulfonated montmorillonite (SMMT) have been developed. Sodium montmorillonite (NaMMT) has been sulfonated with 4-sulfophthalic acid and incorporated into the SPSf matrix for further enhancement of proton conductivity. Sulfonation of NaMMT has been confirmed using Fourier transform infrared spectroscopy and X-ray diffraction (XRD) analysis. The XRD patterns proved that the SMMT layers were completely exfoliated within the SPSf matrix. The performances of the PEM in terms of their liquid uptake, oxidative stability, and proton conductivity were investigated. The morphological characterizations have been carried out using scanning electron microscopy and atomic force microscopy. SPSf/SMMT membrane with 5 wt% of SMMT loading showed adequate thermal stability and an improved proton conductivity. The reduction in methanol permeability from 8.9 ×10−5 cm2 s−1 to 2.4 × 10−5 cm2 s−1 has been observed when SMMT loading content increased from 1 wt% to 5 wt%. Direct methanol fuel cell (DMFC) performance showed a power density value of 49 mW cm−2for SPSf/SMMT membrane, indicating its candidature for DMFC applications.

A novel bioresin, epoxidized soybean oil was synthesized by in situ method and was characterized employing FTIR and NMR. The bioresin was blended with epoxy (DGEBA) at different ratios as reactive diluents for improved processibility and toughened nature. The composition with 20 wt% bioresin exhibited improved impact strength to the tune of 60% as compared to virgin epoxy. Fracture toughness parameters critical stress intensity factor (KIC) and critical strain energy release rate (GIC) were evaluated using single edge notch bending test and demonstrated superior enhancement in toughness. Dynamic mechanical, thermal, thermo mechanical and fracture morphological analyses have been studied for bio-based epoxy blends. Curing kinetics has been evaluated through DSC analysis to investigate the effect of bioresin on cross-linking reaction of neat epoxy with triethylenetetramine as curing agent.

A candid approach to analyze the performance characteristics of phenyl phosphonate-functionalized zirconium oxide and pure zirconium oxide (ZrO2) fillers reinforced chitosan nanocomposites and their suitability as a potential biomaterial for the development of transducer surface in biosensing device has been investigated in this communication. Functionalization of ZrO2 has been carried out using sulfophenylphosphonate which was confirmed using Fourier transform infrared spectrographs. The electrostatic intercalation of chitosan with filler particles was monitored using electrochemical impedance analyzer which exhibits lowest bulk resistance which is highly effective for ionic switching. Incorporation of zirconium sulfophenylphosphonate (ZrSP) the ionic conductivity of the chitosan film attained a value of 1.2 × 10−6 S/cm as compared to the unmodified one which is a prefeasibility work for the fabrication of biosensing platform. Variation in performance characteristics has been evaluated through morphological and thermal characterization. TGA and DSC analysis reveal that the thermal stability and decomposition temperature of the nanocomposites were improved by the addition of reinforcing filler particles. XRD and SEM and TEM results support the above assumption. The continuous alignment of the proton transfer channels of the nanocomposites was thoroughly investigated by AFM analysis which revealed phase morphology for improved enzyme entrapment. Further, surface functionalized nanofillers result considerable increment of mechanical properties in terms of elastic modulus and tensile stress.

This article is designed to review the developments in synthesis, modifications, and properties of epoxy monomers derived from both petroleum and renewable resources. It begins with the enhancement in epoxy monomer properties such as mechanical, thermal, adhesive, barrier, etc. by addition of flexible polymer and elastomers. It also explains the role of organic/inorganic fillers on epoxy monomers to achieve the desired properties for outdoor applications. The effects of chemical/physical treatments on fiber are reviewed and their improvements with epoxy monomers are also observed. The authors also suggest for further improvement of epoxy monomers to obtain various eco-friendly high-performance applications.

This study reports an investigation on the effect of non-ionic surfactant (Triton X-100) on the dispersion of multiwalled carbon nanotubes (MWNTs) inside the polymer matrix. Adsorption of triton X-100 to the MWNTs was confirmed through FTIR. A reduced bundling of MWNT fibrils were noticed in Triton X-100 modified MWNTs (Tr-MWNTs). The polymer nanocomposites were prepared via melt blending technique. The optimization of loading ratio of the MWNTs and Tr-MWNTs was carried out on the basis of mechanical properties. Dynamic mechanical analysis exhibited the much uniform dispersion of the Tr-MWNT inside polymer matrix as compared to that of MWNTs. A faster rate of crystallization was noticed in case of MWNT reinforced nanocomposites, however, a strong filler-polymer interaction could be seen in case of Tr-MWNT filled nanocomposites. Optical microscopic analysis exhibited similar effect of MWNT and Tr-MWNT on the spherulite size of the polymer.

Polylactide (PLA) is an important biodegradable polymer, used for numerous applications ranging from industrial packaging to tissue engineering. However, its inherent brittleness and limited thermal stability have restricted its penetration to niche markets. In this communication, the authors demonstrate that blending of PLA with castor oil-based polyurethane prepolymer (COPUP), with the addition of COPUP, dispersed in the PLA matrix can overcome the inherent brittleness of the matrix polymer. NCO-terminated COPUP was successfully synthesized and subsequently mixed with variable concentration of PLA matrix using melt blending technique. The interfacial compatibilization between COPUP and PLA phase happened by the reaction of −NCO groups with terminal hydroxyl groups of PLA was confirmed by FT-IR peak deconvolution technique. As indicated by the results of DMA and DSC, the glass transition temperature (T g) of both PLA and COPUP shifted closer together, indicating that the blend compatibility increased. The tensile properties and notched Izod impact strength of the PLA and toughened PLA are also investigated. With the addition of 30 % COPUP concentration, the elongation at break of the blend reached 377.46 %, and a notched Izod impact 269.62 J m−1. With improved toughness, the PLA/COPUP blends could be used as replacements for some traditional petroleum-based polymers.

The present work focuses on the effect of organically modified nanoclays on the fire resistance and processability characteristics of poly(methyl methacrylate) (PMMA). PMMA nanocomposite of cloisite 30B (methyl tallow bis-2 hydroxyethyl quarternary ammonium salt modifier) (C30B) was prepared by melt blending technique. A comparative study of flame retardant characteristics of virgin and filled matrix was carried out using cone calorimeter at a heat flux of 50 kW m−2, and the service temperature range was analyzed from thermogravimetric analysis. Parallel plate rheometry revealed the variation in processability as a function of C30B reinforcement and corresponding melt strength of the samples was evaluated through complex viscosity, storage, and loss modulus. Similarly, application-level modulus values were evaluated through viscoelastic properties by dynamic mechanical analysis. Supportive information for the observations from the above characterization was conducted using morphological studies by X-ray diffraction and transmission electron microscopy.

Green nanocomposites of poly(lactic acid)/banana fibre/nanoclay were successfully prepared using melt-blending technique followed by injection moulding. Untreated and chemically modified banana fibres and organically modified nanoclay (Cloisite 30B) were used as reinforcing agent within the poly(lactic acid) matrix. The banana fibres were subjected to various chemical modifications such as mercerization, silane treatment, sodium lauryl sulphate treatment, permanganate treatment and combination of mercerization and silane treatment. The biocomposites and bionanocomposites were subjected to characterization tests i.e. mechanical properties, dynamic mechanical analysis, differential scanning calorimetry, thermogravimetric analysis, heat deflection temperature (HDT), morphological properties using scanning electron microscopy and transmission electron microscope and water-absorption studies to evaluate the effect of chemical modification of banana fibre and incorporation of nanoclay. Silane-treated fibre-reinforced poly(lactic acid) composites and its bionanocomposites displayed optimum tensile and flexural properties than that of virgin poly(lactic acid) resin, whereas the impact strength of composites showed a reverse order due to the brittle nature of matrix. Dynamic mechanical analysis result shows that the storage modulus of the bionanocomposites increases with respect to the virgin poly(lactic acid) and biocomposites. Differential scanning calorimetry results revealed that the glass transition was not significantly changed; however, the incorporation of both silane-treated fibre and C30B nanoclay enhanced the nucleation of poly(lactic acid) crystallites as well as increased the melting temperatures. The results of thermogravimetric analysis depicted that fibre modification and incorporation of nanoclay can improve the degradation temperature of the composites. Scanning electron micrographs demonstrated improper dispersion of untreated fibres and proper dispersion of treated fibres within the poly(lactic acid) matrix, thereby revealing the interfacial adhesion between the fibres and matrix. Additionally, the composites were subjected to water-absorption studies, which revealed that bionanocomposites exhibited better water resistance than biocomposites.

This research aims to study the effect of accelerated weathering conditions on the photodegradation characteristics for fibrillar silicate clay-filled Polypropylene (PP) nanocomposites in the presence of metallocene linear low density polyethylene (m-LLDPE). Silane-treated attapulgite (ATP) clay along with ethylene octene elastomer-grafted maleic anhydride (POE-g-MAH) was used to compatibilize both blend and nanocomposite system. The result showed that developed PP/m-LLDPE nanocomposites displayed good UV resistance with little change in retained stress-at-break and elongation-at-break values. Balanced loss of toughness values noted maintaining higher fracture toughness values for nanocomposites containing 5 phr ATP clay. Infrared analysis was used to detect progress of degradation followed by change in carbonyl index revealed predominated chain scission in late irradiation, while crosslinking was dominant for initial irradiation period. An increase in crystallinity during UV exposure (chemi-crystallization) was detected with exposure time for all compositions and virtually independent of initial structure of the polymer. The highest value of crystallization observed for PP and the lowest one for nanocomposites containing 5 phr of ATP clay revealed good oxidation stability. Surface morphology revealed induced degradation throughout cross-section of PP, while severity of the surface degradation was significantly reduced for developed nanocomposites.

This work reports a novel approach towards a chemical-free treatment of nanoclay through extensive thermal exposure. Dehydroxylation at high temperature was utilized to enhance the influence of nanoclay on the properties of polymer. The effect of this treatment of nanoclay, on the polymer properties, with reference to Polypropylene (PP) has been investigated. The FTIR spectra revealed the successful removal of water from the intergallery spacing of the nanoclay. The maintained structural configuration of the clay was confirmed using WAXD pattern. The uniform dispersion and exfoliation of thermally treated clay layers inside the polymer matrix was confirmed through enhanced mechanical properties. Improved crystallization properties, thermal stability and flame retardant characteristic were also noticed in the nanocomposites reinforced with thermally dehydroxylated clay. This study revealed that the dehydroxylation approach of modification of nanoclay may provide much enhanced properties of polymer, without involvement of any chemical for modification.

The present investigation focuses on the effect of fiber surface treatment on the mechanical, thermal and morphological properties of sisal fiber (SF) reinforced recycled polypropylene (RPP) composites. The surface of sisal fiber was modified using different chemicals such as silane, glycidyl methacrylate (GMA) and O-hydroxybenzene diazonium chloride (OBDC) to improve the compatibility between fiber surface and polymer matrix. The experimental results revealed an improvement in the tensile strength to 11 %, 20 % and 31.36 % and impact strength to 78.72 %, 77 % and 81 % for silane, GMA and OBDC treated sisal fiber reinforced recycled polypropylene (RPP/SF) composites respectively as compared to RPP. The thermo gravimetric analysis (TGA), Differential scanning calorimeter (DSC) and heat deflection temperature (HDT) results revealed improved thermal stability as compared with RPP. The morphological analysis through scanning electron micrograph (SEM) supports improves surface interaction between fiber surface and polymer matrix.

In the present study, the combined effect of multiwalled carbon nanotube (MWNT) and organoclay in improving the flame retardancy and thermal stability was evaluated. A novel ternary nanocomposite (polymer/organoclay/MWNT) material based on polypropylene, organoclay and MWNTs has been developed. Higher degree of delamination of clay layers in ternary nanocomposites as compared to polymer/clay nanocomposites via x-ray diffraction and transmission electron microscopy analyses was evident, and also the network structure of MWNT and clay was evident. In ternary nanocomposites, the more intact network structure was also evident from the rheological assessment. Improved thermal stability and flame-retardancy characteristics were evident from thermogravimetric and cone calorimeter analyses. Also the scanning electron microscopic micrographs of char residue revealed a correlation with the cone calorimeter. The role of degree of graphitization of MWNTs on the flammability of nanocomposites was also confirmed from the analysis.

This study presents a novel approach towards clay modification via thermal dehydroxylation, for polymer nanocomposite application. The feasibility of modification of clay via thermal dehydroxylation and its influence on the polymer properties was investigated, with reference to the polyproplylene (PP) nanocomposites. In spite of ample available literatures on organophillic clay/polymer composites, use of organic compound for the clay modification has been found detrimental in various aspects. Therefore, in order to corroborate the advantage of the thermal dehydroxylation method over organophillic modification, a comparative aspect of the effect of the organically modified and thermally dehydroxylated clay on the polymer properties has been established. Wherein, remarkably greater mechanical, dynamic mechanical, thermal and microstructural properties were noticed in case of nanocomposites reinforced with thermally dehydroxylated clay. Modification of clay via thermal dehydroxylation method was foun...

In the present study, a novel approach of wet mechanochemical oxidation of carbon nanotubes (CNTs) has been established in order to improve the uniformity in nanodispersion of the CNTs. This approach was found to be more efficient for CNT oxidation as compared to the acid oxidation method as observed from the Fourier transform infrared spectroscopy and titrometric analyses. From the x-ray diffraction and Raman spectroscopic analyses, it was also noticed that the damage to the surface of CNTs caused by acid can be prevented using wet mechanochemical process for oxidation. The transmission electron microscopic micrographs also revealed lesser degree of entanglement of the CNT fibrils. The polymer nanocomposites reinforced with wet mechanochemically oxidized CNT (McCNT) revealed considerably higher mechanical properties as compared to that of acid-oxidized CNTs. Also, the much higher uniformity in dispersion and nucleating effect of the McCNT was observed from the Raman spectroscopy and differential scanning calorimetry analysis, respectively.

The objective of this work was to study the compatibilizer effect on polypropylene (PP) and acrylonitrile butadiene styrene (ABS) blends. The blends were coextruded and injection molded in various ratios of ABS with and without compatibilizers. Universal testing machine was employed to analyze the tensile properties of basic PP/ABS binary blends. From the mechanical testing, the impact and tensile properties of PP/ABS blend were optimized at 80/20 weight ratio. Various compatibilizers such as PP-g-MAH, SEBS-g-MAH and ethylene α-olefin copolymer were used and their comparative performance on binary blend was enumerated. Hybrid compatibilization effect was also studied and reported. However, the addition of compatibilizers showed the maximum increase in impact strength attributed to rubber toughening effect of ABS. The effect of compatibilizers on morphological properties was examined using scanning electron microscopy (SEM). SEM micrographs depicted the more efficient dispersion of ABS particles in PP matrix with the addition of compatibilizers. Further, interparticle distance analysis was carried out to evaluate the rubber toughening effect. The ABS droplet size in compatibilized PP/ABS blend was brought to minimum of 3.2 μm from 9.9 μm with the addition of compatibilizers. The melt rheology of PP/ABS blend systems was investigated through parallel plate arrangement in frequency sweep. Linear viscoelastic properties like storage (G′) and loss (G″) modulus and complex viscosity (η*) have been reported with reference to the virgin materials. It is understood that the combination of compatibilizers (hybrid compatibilizer) had a considerable effect on the overall blend properties.

A candid approach to analyze the prospects of organic–inorganic nanocomposites as polyelectrolytes has been presented in this communication. Structurally modified aromatic sulfone polymer, polysulfone, was successfully prepared through modification with trimethyl silyl chlorosulfonate, which was confirmed from Fourier transform infrared spectrographs. Different classes of nanofillers like layered silicates and inorganic oxides were reinforced in the modified macromolecular system using solvent casting technique. A comparative study was performed to evaluate the effectiveness of filled polyelectrolyte membranes in a direct methanol fuel cell operated at 60°C with 1.0 M methanol feed. Atomic force micrographs revealed the phase morphology, responsible for this behaviour. The variation in ion transfer behavior as a function of structural modification and filler composition was also conducted. Furthermore, supportive information for these characterizations were derived from morphological (x-ray diffractometry), thermal (thermogravimetric analysis), and liquid uptake studies.

In the present study, sulfonated polysulfone (SPSU (T)) was prepared from PSU using trimethyl silyl chlorosulfonate as a sulfonating agent. Volumetric analytic studies revealed 58% degree of sulfonation and 1.15 meq g−1 ion-exchange capacity of SPSU (T). Fourier transform infrared spectra also confirmed the occurrence of sulfonation reaction in SPSU (T). Subsequently, nanocomposite membranes were prepared by incorporating variable quantities of Cloisite 30B (C30B) within the SPSU (T) in N-methyl-2-pyrrolidone employing solution casting method. All the membranes were characterized for thermal analysis, liquid uptake, swelling behavior, and proton conductivity measurements. Thermogravimetric analysis revealed that incorporation of C30B increased the thermal stability of the membranes. Morphological study of the nanocomposite membranes was also evaluated using scanning electron microscopy and atomic force microscopy. The x-ray diffraction patterns of nanocomposite membranes confirmed exfoliation of C30B clay galleries within the SPSU (T) matrix.

A two-step process was used to prepare PP/MAPP/C15A/MWNT ternary nanocomposites system. The effect of the addition of MWNT on the delamination of clay layers in the polymer matrix has been studied through XRD. The similar crystallinity level was noticed after the addition of clay and MWNT together in the PP matrix through XRD. Higher mechanical properties of the ternary nanocomposites system were noticed than neat PP and its binary nanocomposites systems. Differential scanning calorimeter (DSC) technique was utilized to investigate the effect of both nanofillers on crystallization temperature (TC). And a shift in TC towards higher temperature was noticed in all the nanocomposites. Thermogravimetric analysis revealed an improved thermal stability of the ternary nanocomposites system. The dynamic mechanical response of PP and its binary and ternary nanocomposite systems was evaluated. The dispersion of the nanoparticles was investigated employing transmission electron microscopy (TEM). The combined effect of clay and MWNT on the properties of PP was investigated and summarized.

Poly(ethylene glycol) (PEG) was mixed at various weight percentage with biodegradable poly(lactic acid) (PLA) via direct melt compounding method. Nanocomposites of PLA/PEG, with two types of organoclay namely, cloisite 93A (C93A) and cloisite 30B (C30B) were also prepared by melt blending method. The crystallization behaviors of PLA/PEG and PLA/PEG/organoclay were studied using differential scanning calorimetry (DSC). The isothermal crystallization kinetics has been investigated using the Avrami’s equation. In PLA/PEG, the PLA crystallized first followed by crystallization of PEG during the cooling. The viscoelastic behavior of the PLA/PEG and PLA/PEG/organoclay were investigated by dynamic mechanical analysis where the nanocomposites showed higher magnitude of storage modulus. The plasticizing effect of PEG acts predominantly in the mechanical performance of PLA/PEG, which shows increased percentage elongation and impact strength in the blend. The sample with 20 wt% PEG showed optimum impact strength. Again, the nanocomposite with 3 wt% C30B exhibited better tensile strength and modulus than the sample with C93A. The characterization of fractured surface of the matrix polymer and the blend were compared through scanning electron microscopy. The rheological and compostability study of the system were further investigated.

Polymer electrolyte membranes (PEMs) were developed for direct methanol fuel cell (DMFC) applications, based on sulfonated polyether ether ketone (SPEEK) and polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) filled with Cloisite 30B (C 30B) as a solid hydrophilic proton conductor. PEMs were characterized using liquid uptake, oxidative stability, TGA, XRD, SEM, AFM and impedance analysis. The single cell DMFC performance reveals that the optimized PEM showed an open circuit voltage (OCV) of 0.79 V and a maximum power density value of 55 mW cm−2 with a proton conductivity value in the range of 10−2 S cm−1. The methanol permeability and selectivity ratio of the optimized membrane were 1.35 × 10−7 cm2 s−1 and 9.63 × 104 S s cm−3, respectively. As a result fabricated membranes could be seen as promising PEMs for DMFC applications.

A new approach of oxidation of carbon nanotubes has been used to oxidize the CNTs. A comparative aspect of the mechanical oxidation and acid oxidation process has been established. FTIR analysis and titration method have shown the higher feasibility of the mechanical oxidation method to oxidize the CNTs. Comparatively less damage to the CNTs has been observed in case of mechanically oxidized as compared to acid oxidized CNTs. The mechanical properties of the nanocomposites reinforced with the acid oxidized CNT (ACNT) and mechanically oxidized CNTs (McCNT) were analyzed and relatively higher properties in the nanocomposites reinforced with McCNT were noticed. The less degree of entanglement in the McCNTs was noticed as compared to ACNTs. The dynamic mechanical analysis of the nanocomposites revealed much improved load transfer capability in the McCNT reinforced composites. Further, the rheological properties of the nanocomposites revealed the higher performance of McCNT reinforced composites.

This study highlights successful development and evaluates the characteristics of graphene-derived nanohybrids (SGO and RSGO) incorporated MMM systems. Pristine GO and modified SiO2 (mSiO2) based membranes have also been prepared to assay the established synergistic effect on the performance. FTIR and WCA studies were carried out to endorse the insertion of different nanofillers into the virgin PSf matrix. SEM with EDS and AFM were accomplished to substantiate the distribution and dispersion pattern of the fillers within the base matrix. From the mechanical analysis, 46% improved tensile strength was perceived for the hybrid MMM system containing SGO. Finally, the dexterity was documented by analyzing the permeation behavior of the prepared membranes towards the selected O2/N2 gas pair. The hybrid PSf/SGO system displayed 605% and 801% higher permeabilities for O2 as compared to the parent counterparts: (PSf/mSiO2, PSf/GO), respectively. Meanwhile, PSf/RSGO membrane exhibited a slightly reduced performance than the former hybrid system.

In this paper, two types of fillers such as expanded graphite flakes (EG) of 20 μm particle size and silver flakes (Ag) of 10 μm particle size were used for thermal conductivity (TC) enhancement of neat epoxy resin. Mix and heat based simple method were used to produce hybrid thermal filler which was reinforced in epoxy for composite formation. Disc-shaped epoxy composite samples with different hybrid filler formulations were prepared by hand layup and mechanical mixing technique. The thermal conductivity of single (EG) and mixed (EG/Ag1) hybrid epoxy adhesive composites was measured according to ASTM E1530 standard at 60 °C. It was increased to 2.511 (˜13 times) and 3.42 W/mK (˜17 times) than neat epoxy at 30 wt.% loading level inside the epoxy matrix, respectively. This indicates the commercial use of this adhesive formulation for thermal interface materials application. From scanning electron microscopy (SEM), we observed the conducting network formation through EG and EG/Ag hybrids inside the low conducting epoxy matrix. The lap shear strength (LSS) of epoxy resins with the incorporation of 30 wt% EG/Ag was decreased as compared with neat epoxy.TGA analysis showed that the introduction of Ag inside epoxy hybrids has influenced more negative impact on the thermal stability of epoxy composite at initial stages.

The utilization of solar energy by virtue of which, an economically viable, steady and sustainable device fabrication are the need for future generation. In this regard, the replacement of platinum (Pt) free counter electrode (CE) in dye sensitized solar cell (DSSC) is probed for widespread application. In this study, our aim is to improve the ability of charge transfer as well as to increase the active site with the enrichment of catalytic activity of CEs. NiCo2O4 decorated reduced graphene oxide (NCG) sheets were synthesized by chemical precipitation route and subsequently polymerized with aniline for NCG-polyaniline (PANI) complex for efficient CEs in DSSC. The prepared CE significantly amplifies the charge transfer capability of ternary complex and it is reflected for the proficient reduction towards I-/I3 redox shuttles. The fabricated CE (NCG-PANI) yield maximum photo-to-electron conversion efficiency of 4.67% which is higher than NCG based DSSC (4.1%). The study suggests that NiCo2O4/rGO/PANI (NCG-PANI) CEs with higher electrocatalytic performance and efficient charge transfer activity prepared by cost effective technique could be potential for Pt-free DSSC applications.

Partially miscible blends of poly(lactic acid) (PLA) and poly(hydroxybutyrate) (PHB) have been prepared by the melt mixing method. An interpenetrating network structure created by a maleic anhydride (MA) compatibilizer imparted additional interactions between the two matrices, which has resulted in increased miscibility within the blends. A modified interface has been characterized using morphological analysis through FT-IR and SEM analysis. Because MA compatibilization distributed flexible intermolecular hydrogen bonding within the blend matrix, elongation at break and Izod impact strength has been reported at a maximum of 540.17% and 99%, respectively, compared to those of the PLA matrix. Further, incorporation of layered silicates within the optimized composition of the PLA/PHB/MA blend modified the tensile strength by 49%, without compromising its superior flexible characteristics. Simultaneously, the renowned thermal insulating property of exfoliated/intercalated layered silicate works well to promot...

Agricultural mulch film of poly(lactic acid) (PLA) has been prepared under industrial conditions by the extrusion blown film method with modified properties using poly(hydroxibutyrate) (PHB) and reactive compatibilizer maleic anhydride (MA). Processing parameters and blend composition have been optimized based upon processability and mechanical properties of the final materials. Because PLA is a biopolymer, evaluation of service life period of the mulch film is very much important. Sustainability of the film has been analyzed by keeping the films in a weatherometer, which can create accelerated weather conditions, followed by mechanical testing at regular intervals. Similarly, variation in compostability has been analyzed as per the American standard for test method, ASTM D 5988, using vermi-compost. In addition, specific microbial action on the mulch films also has been analyzed using bacteria Berkholdaria cepacia (B. cepacia), which is selective in particular toward PLA degradation and in mixed fungal i...

Interfacial agents such as compatibilizers have recently been introduced into polymer blends to improve microstructure and mechanical properties of thermoplastics materials. This method is proven to be an effective way to prepare a mixture of polymeric materials from E-waste that can have superior mechanical properties over a wide temperature range. This study is focused on the characterization and mechanical recycling of plastics, namely Polycarbonate (PC), Acrylonitrile Butadiene Styrene (ABS) and PC/ABS blends via melt blending technique. Mechanical characterization of prepared blend has been carried out to determine the optimum composition range. The experimental results showed that the prepared blends were incompatible in nature. Addition of maleic anhydride grafted ABS and SBS suggests improved compatibility and impact performance. The grafting mechanism of MA into ABS was explored, which is considered as a key factor resulting a special morphology of ABS domains dispersed in PC matrix. The thermogravimetric analysis (TGA), differential scanning calorimeter (DSC), and morphology results revealed improved stability as compared to recycled plastics.

Organically modified montmorillonite (OMMT) has been incorporated up to 7 wt% in poly(3-hydroxybutyrate) (PHB) by melt compounding in a twin screw extruder. PHB nanocomposites reinforced with C93A showed significant increase in tensile and flexural modulus and impact strength comparatively. Wide angle X-ray diffraction showed an increase in overall d-spacing indicating intercalated structure. The intercalation morphology was further supported by transmission electron microscope images indicating formation of intercalated structure in case of PHB/OMMT and a mixture of Intercalated/exfoliated structure in case of PHB/TMI-MMT nanocomposites. Thermogravimetric analyses indicate that the thermal stability of PHB/TMI-MMT nanocomposites is higher among all other nanocomposites under investigation and virgin PHB. Differential scanning calorimetry (DSC) analysis of PHB nanocomposites shows marginal increase in glass transition temperature and decrease in crystallization temperature compared to virgin PHB. The isothermal crystallization kinetics of PHB/C93A nanocomposites was investigated by DSC in the temperature range of 100–120°C and the development of relative crystallinity with the crystallization time was analyzed by Avrami equation. POLYM. COMPOS., 35:999–1012, 2014. © 2013 Society of Plastics Engineers

In this study, the effect of poly(ethylene glycol) (PEG) on the preparation of Poly(lactic acid) (PLA)/PEG blend and its nanocomposites by melt intercalation method were investigated. The PEG having molecular weight of 6,000 g/mol used with various concentrations (0, 10, 15, 20, 25, 30 wt%) in the preparation of PLA/PEG blend. Again, two types of commercialized organoclay [cloisite 93A (C93A) and cloisite 30B (C30B)] were used for the preparation of blend nanocomposites. With the incorporation of PEG into PLA the tensile strength and modulus decreases, whereas the percentage elongation and impact strength increases predominantly. Further, the PLA/PEG blend nanocomposites showed improved tensile strength and modulus with the addition of oraganoclays into the blend. Scanning electron microscopy (SEM) reveals the surface and miscibility study of the PLA/PEG blend. The effect of clay interaction in the PLA/PEG blend nanocomposites were also studied by using wide angle X-ray diffraction (WAXD) and transmission electron microscopy (TEM). Dynamic mechanical analysis (DMA) was used to investigate the viscoelastic behavior of the blends and its nanocomposites. Differential scanning calorimetry (DSC) study reveals decreased glass transition temperature in case of PLA/PEG blend. The thermal stability of the blend and its nanocomposites were being studied by using thermogravimetric analysis (TGA). POLYM. COMPOS., 35:283–293, 2014. © 2013 Society of Plastics Engineers

Shape-memory polyurethane (SMPU) having segmented structure, with 4,4-diphenylmethane diisocyanate as hard segment, poly caprolactone diol 4000 as soft segment, and 1,4-butane diol as chain extender was synthesized using two-step polymerization technique. This pure SMPU was blended with unmodified and modified multiwalled nanotubes (MWNTs), using twin screw extruder and melt spinning technique. X-Ray diffraction, differential scanning calorimetry, morphological analysis, and shape-memory behavior results for the SMPUs are presented in this study. An improvement in the thermal stability and degradation temperature of the SMPU was observed especially in the soft segments, upon 0.1% loading of MWNT. Slight decrease in crystallinity was recorded for MWNT/SMPU as compared to virgin SMPU. The recovery ratio of SMPU fiber increased to 90% with 0.1 wt% loading of MWNT, but the spinnability decreased due to reduced crystallinity and viscosity with an addition of nanotubes to the polyurethane matrix.

Mechanical properties and deformation mechanism of polypropylene (PP) filled with different weight percentage of ethylene–octene copolymer (EOC) and fibrillar silicate attapulgite (ATP) clay were investigated under uniaxial cyclic loading at constant crosshead speed to evaluate plasticity/damage coupling behavior. With increasing EOC and clay content, PP exhibited typical plastics response with marked stress drop at yield followed by steady state plastics region up to rupture. The addition of 3 wt% ATP clay to the PP/EOC blend shows enhanced impact strength up to four times compared to PP with decrease in yield strength by 24% implied synergistic toughening effect. Volume strain, which characterizes deformation damage, steadily increased over the whole plastics stage up to 5.2 for axial strain of 0.30 after a critical tensile strain of 0.05. The small energy value observed for large volume strain revealed matrix shear deformation as the controlling factor for energy dissipation without crazing. Fractography observation using scanning electron microscopy revealed formation of debonding and cavitations on the surface of PP matrix, contributing increase in the volume of all compositions.

Polylactic acid (PLA) is a completely biodegradable potential replacement for petroleum based plastics used for various commodity applications. However, difficulties in processability and cost restrict the polymer to clinch its niche in the market. Present investigation tried to modify the processability and cost of the PLA without compromising its inherent highlighted properties like good mechanical performances and biodegradability. Chemically treated banana fiber (BF) and organically modified nanoclay (cloisite 30B) has been incorporated as reinforcing fillers within the PLA matrix by melt mixing method. Various silane coupling agents and NaOH have been used for the chemical modification of BF to improve the interfacial interaction with PLA macromolecules. Performance characteristics of optimized composition of BF reinforced PLA bionanocomposite was evaluated through mechanical, thermal and flammability characteristics. Further, the newly developed bionanocomposite has been used for preparing biodegradable cutlery under industrial conditions.

This study discusses the influence of incorporation of natural fiber on the performance of recycled polypropylene composites. Composites consisting of polypropylene (PP) and sisal fiber were prepared through mixing and compression process, in various proportions. The surface modification of the fibers has been carried out, using various chemical treatments. Mechanical properties of the systems have been evaluated. A comparative study has been conducted between the theoretical as well as experimental results using various suitable models. The impact of treatment of the fibers on the thermal and flammability properties has also been investigated. The interfacial properties have been interpreted from scanning electron micrographs (SEM).

The feasibility of sulfonated poly(ether ether ketone) (SPEEK) membranes reinforced with unmodified silica (SiO2) and modified silica (SiO2–SO3H) nanoparticles as proton exchange membranes (PEMs) was investigated here. The sulfonated membranes were characterized for degree of sulfonation, thermal stability, as well as water/methanol uptake properties. The incorporation of SiO2 increased the hydrophilic behavior thus allowing more water retention, which facilitated an easy pathway for proton transfer. However, a reduction in proton conductivity was observed. The strong –SO3H/–SO3H interaction between SPEEK chains and SiO2–SO3H led to ionic cross-linking in the membrane structure, which compensated for this decrement in proton conductivity. The fuel cell performance study revealed the potential of SPEEK/SiO2–SO3H nanocomposite membrane to act as an efficient PEM for fuel cell application.

Nucleation capacity of organically modified natural montmorillonite within the surface-treated banana fiber (BF)-reinforced PLA biocomposites has been studied using DSC analysis in the present investigation. Both the surface treatments and nanoclays play vital roles in the variation in nucleation process of PLA during cold crystallization process. Biocomposite made up of silane-treated BF and its bionanocomposite prepared using cloisite 30B (C30B) were showed superior nucleation parameters, n and K values, in the Avrami plots. Enhanced equilibrium melting point and lower E a suggests the reinforcing effect imparted by the BF surface treatments and C30B within the PLA matrix. Even though, Louritzen–Hoffmann theory was revealed that no change in crystallization regimes of PLA even after the biocomposite and bionanocomposite preparation. TG analysis revealed better heat barrier capacity for all the biocomposites and bionanocomposites in comparison with virgin PLA (V-PLA). Increased storage modulus values for biocomposites and bionanocomposites also confirm the reinforcing effects of the fillers. Heat deflection temperature and the flammability studies concluded better application window for newly developed materials than that V-PLA.

Polylactic acid nanocomposite was prepared by melt blending polylactic acid (PLA) and transition metal ion (TMI)-modified montmorillonite (MMT; TMI-MMT) using a co-rotating conical twin-screw microcompounder attached with a mini injection moulder. MMT was modified by ion exchange reaction using TMI. Intercalation morphology of TMI on MMT was investigated by x-ray diffraction (XRD) and transmission electron microscopic analyses. XRD patterns indicated penetration of the metal ions into the MMT interlayer and formation of intercalated structure. In order to increase the adsorbed amount of Zn2+ and Cu2+ ions, MMT was previously intercalated with ethylene diamine. Thermogravimetric analysis indicated an increase in the onset of degradation temperature of nanocomposites when compared with virgin PLA. The isothermal cold crystallization kinetics of PLA/TMI-MMT nanocomposites was investigated by differential scanning calorimetry in the temperature range of 100–120°C and the development of relative crystallinity with the crystallization time was analyzed by the Avrami equation. PLA nanocomposites reinforced with TMI-MMT showed a significant increase in tensile and flexural modulus and impact strength when compared with virgin PLA. The flammability studies of PLA/TMI-MMT nanocomposites displayed slow rate of burning and enhanced carbonaceous char formation when compared with virgin PLA matrix.

Nanocomposites containing nano-calcium carbonate (nano-CaCO3) in the range of 0.25–1.5% (w/w) were prepared via in situ polymerization of urethane methacrylate pre-polymer derived from poly(ethylene glycol) (PEG 400), polymeric diphenylmethane diisocyanate and 2-hydroxyethyl methacrylate. Incorporation of nano-CaCO3 into poly (urethane methacrylate) matrix was confirmed by Fourier transform infrared spectroscopy and wide-angle x-ray diffraction studies. Density studies indicated that nanocomposites containing 0.75 wt% nano-CaCO3 had more condensed microstructure. Tensile strength, abrasion resistance, heat deflection temperature and shore hardness of nanocomposites were found to be higher than that of pristine polymer. Impact strength decreased with an increase in the nano-CaCO3 content. Thermal studies indicated single-step degradation under a nitrogen atmosphere. Scanning electron microscopy studies confirmed the uniform distribution of nano-CaCO3 at lower loading of nano-CaCO3 and microcracking occurred during wearing.

This work is focused on the modification of montmorillonite by hexadecyl trimethyl ammonium bromide (HDTMA) as a surfactant by cation exchange reaction. HDTMA-modified layered silicate (HDTMA-MLS) was compounded with polylactide (PLA) by melt extrusion technique for making nanocomposites. These nanocomposites were subjected to morphological, rheological, thermal and mechanical analyses. Variations in mechanical properties, plasticity and thermal stability with the addition of modified nanoclays in PLA were investigated. The presence of HDTMA in clay minerals was confirmed by Fourier-transform infrared (FTIR) analysis that shows two absorption bands at 2927 cm−1 and 2860 cm−1 that corresponds to the asymmetric and symmetric stretching vibrations of C–CH2 of alkyl chain, respectively, and the band at about 1470 cm−1 was assigned to the vibration of trimethyl ammonium quaternary group C–N(CH3)3. Melt rheology of virgin PLA and nanocomposites performed by small amplitude oscillation shear measurement. Incorporation of HDTMA-MLS (1–7 wt%) into PLA matrix yields significant improvements in the elastic modulus ( G′) of nanocomposites due to intercalation at high temperature. X-Ray diffraction (XRD) and transmission electron microscopy determined that PLA/HDTMA-MLS nanocomposites were intercalated. Nanocomposite prepared using 5 wt% HDTMA-MLS exhibited optimum mechanical performance with an increase in the tensile and flexural modulus and impact strength as compared to virgin PLA, which confirms intercalation morphology. Dynamic mechanical analysis study revealed an increase in the storage modulus ( G′) confirming a strong interaction between the modified clays and PLA. Differential scanning calorimetry and thermogravimetric analysis showed improved thermal properties. Heat deflection temperature of the matrix also increases in the presence of nanoclays.

Polylactic acid (PLA) nanocomposites were prepared using melt blending technique. Two different commercially available nanoclays, Cloisite 93A (C93A) and Cloisite 30B (C30B) at various wt%, have been used to prepare the nanocomposites. The mechanical properties of the nanocomposites have been studied to evaluate the effect of the nanoclay within the matrix polymer. Mechanical tests revealed an increase in the mechanical properties with the incorporation of organically modified nanoclays as compared with PLA matrix. PLA/C30B nanocomposites exhibited optimum tensile modulus at 3 wt% of clay loading. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) studies were also performed to evaluate the thermal behavior of the nanocomposites. Further, viscoelastic behavior in the nanocomposites has been investigated using dynamic mechanical analysis (DMA) to study the damping behavior of the materials. Also the morphological study was carried out through X-ray diffraction analysis, and a better exfoliation or dispersion of C30B clay with PLA matrix was observed. The interaction between the clays and PLA matrix has also been studied using transmission electron microscopy (TEM).

The structure of polysodium acrylate (PSA) hydrogel was modified using N, N-methylenebisacrylamide and cellulose microfibrils (CMFs) as a cross-linker and filler, respectively. CMF was obtained from banana fiber by acid hydrolysis process. The resulting structure and morphology of CMF and PSA/CMF hydrogels were characterized by Fourier transform infrared spectroscopy (FTIR), x-ray diffraction (XRD) analysis and scanning electron microscopy. From the FTIR and XRD spectra, the formation of CMF from banana fiber is confirmed. Differential scanning calorimetric study was carried out on the swollen PSA/CMF hydrogels to determine the state and quantification of water present inside the hydrogels. The mechanical characterization of PSA/CMF hydrogels was studied in brief by dynamic mechanical analysis technique.

Thermally conductive composites and nanocomposites composed of epoxy resin as base matrix and aluminum nitride (AlN) as micro and nanofiller have been studied at variable temperatures and loading of AlN. To improve the dispersion of the filler within the polymer matrix, AlN was surface modified with silane-coupling agent. Thermogravimetric analysis confirmed the interfacial bonding of epoxy- and silane-modified AlN. The dielectric properties of epoxy/AlN composites and nanocomposites have been studied at variable percentage of filler. Test result indicated an increase of thermal conductivity of the composites at 20 wt% of AlN. Also, silane-treated composites exhibited improved electrical conductivity properties, whereas the electrical insulation property decreased in terms of dielectric strength and resistivity. POLYM. COMPOS., 2013. © 2012 Society of Plastics Engineers

Hydroxy terminated polybutadiene is a low molecular weight telechelic, translucent liquid rubber which finds a wide range of applications. The presence of double bonds and hydroxyl end groups can be effectively utilized to chemically modify into various functional groups such as epoxy, urethane, urethane methacrylate, carboxylic acid, ester, amine etc. Further, terminal carbon atom can be also be functionalized. In this review, preparation, properties, chemical modification and applications are discussed in detail.

Polycarbonate (PC)/nanosilica (nSiO2) nanocomposites were prepared by melt-blending technique, in which surfactants are used to enhance the interfacial adhesion between nSiO2 and polymer matrix. Mechanical properties demonstrate increased Young's modulus and yield strength of modified PC/nSiO2 nanocomposites when compared with PC. Increased compatibility further indicates an effective increase in thermal stability as observed from thermogravimetric analysis. Dynamic mechanical analysis point out a reduction in Tg value with increased storage modulus. The flammability characteristics of PC/nSiO2 nanocomposites were evaluated using limiting oxygen index, whereas the morphological properties are characterized by wide-angle X-ray diffraction and scanning electron microscopy. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers

The article focuses on the effect of fiber surface treatment on the properties and performance of sisal fiber (SF) reinforced recycled polypropylene (RPP) composites. Sisal fiber was functionalized using different surface modification methods using silane (Si), glycidyl methacrylate (GMA) and o-hydroxybenzene diazonium chloride (OBDC) in order to improve the compatibility with matrix polymer. The experimental results revealed an improvement in the tensile strength to the tune of 11 %, 20 % and 31.36 % and impact strength to 78.72 %, 77 % and 81 % for silane, GMA and OBDC treated SF reinforced RPP composites, respectively as compared to RPP. Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and heat deflection temperature (HDT) studies revealed enhanced thermal stability of RPP after SF reinforcement. The flammability behavior of surface modified SF/RPP composites were also investigated using horizontal burning method. Improved surface interaction between fiber and polymer matrix was confirmed from scanning electron micrographs (SEM).

Cables and wires are the indispensable parts of electronic equipments for transmission of both information and electricity. Nowadays, data cables are widely used in the computer equipments for sending information and they become waste once its life cycle is completed. However, recycling of cables and wires are mainly concentrating into the recovery of metals such as aluminium and copper, rather than other polymer present. Polymeric materials from the waste data cables are often disposed into landfills or incinerated, since they have only lower value in recycling yard. From the data cables collected, it has been estimated that the major constituents are copper (58.3%), polyvinyl chloride (19.9%) and polyethylene (16%). Similarly, polycarbonate (2.9%), silicon rubber (1.6%), steel (1.4%) and other material (0.4%) such as cotton cord were also present as minor components. Out of these, polyvinyl chloride is the dominant polymer present in data cables. Hence, the present work investigates the reprocessability of the polyvinyl chloride recovered from the data cables and deals with issues such as premature degradation during life cycle, assessment of plasticizers and degradation after reprocessing. Torque measurement studies using torque rheometer revealed further mechanical recycling possibilites of the recovered polyvinyl chloride. Besides, the applicability of melt blending technique for processing recovered polyvinyl chloride can be found out by analysing thermal behaviour by using thermogravimetric analysis, differential scanning calorimetry and heat distortion temperature.