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An investigation was carried out at Vegetables Research Farm of the Department of Horticulture, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, during Zaid season (Feb-May) of 2019 to evaluate 26 genotypes of muskmelon (Cucumis melo L.) for genetic diversity based on 32 morphological and 4 biochemical traits. Since any breeding program’s success depends broadly on the available genetic diversity and the rational selection of parents, the wider genetic diversity of the genotypes offers plentiful room for further improvement in available cultivars. Therefore, Mahalanobis’s D2 statistic was adopted for quantitative assessment of genetic divergence and based on the relative magnitude of D2 values, twelve clusters were formed. Of the twelve clusters, cluster I was largest with the nine genotypes, followed by cluster ? with seven genotypes. Among the traits studied, maximum genetic divergence was contributed by the character seed weight index (15.38%). The maximum inter-cluster distance was recorded between cluster VII and XI (106.09) while, the intra-cluster distance was highest in cluster III (46.03) which marked the presence of wide genetic diversity among the genotypes GP-150, Pusa Madhuras, MHY-3, GP-20, MM-1, Durgapur Selection, and GP-73. The inter-cluster distance was more than the intra-cluster distance indicating the presence of wide genetic diversity, among the genotypes under study.

Purpose The fused filament fabrication (FFF) process is an additive manufacturing technique used in engineering design. The mechanical properties of parts manufactured by FFF are influenced by the printing parameters. The mechanical properties of rigid thermoplastics for FFF are well defined, while thermoplastic elastomers (TPE) are uncommonly investigated. The purpose of this paper is to investigate the influence of extruder temperature, bed temperature and printing speed on the mechanical properties of a thermoplastic elastomer. Design/methodology/approach Regression models predicting mechanical properties as a function of extruder temperature, bed temperature and printing speed were developed. Tensile specimens were tested according to ASTM D638. A 3×3 full factorial analysis, consisting of 81 experiments and 27 printing conditions was performed, and models were developed in Minitab. Tensile tests verifying the models were conducted at two selected printing conditions to assess predictive capability. Findings Each mechanical property was significantly affected by at least two of the investigated FFF parameters, where printing speed and extruder temperature terms influenced all mechanical properties (p < 0.05). Notably, tensile modulus could be increased by 21%, from 200 to 244 MPa. Verification prints exhibited properties within 10% of the predictions. Not all properties could be maximized together, emphasizing the importance of understanding FFF parameter effects on mechanical properties when making design decisions. Originality/value This work developed a model to assess FFF parameter influence on mechanical properties of a previously unstudied thermoplastic elastomer and made property predictions within 10% accuracy.

The objective of this study is to include 5 wt% silane-treated starch (S-t-Starch) into biodegradable flexible poly(butylene adipate-co-terephthalate) (PBAT)/poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) blend matrix, which can facilitate superior barrier and balanced mechanical properties. With the intension of improving compatibilization between matrix and filler, starch (biological macromolecule) was efficiently treated with 15 wt% of 3-glycidoxypropyl trimethoxy silane (GPTMS), a coupling agent. Various analyses such as barrier, mechanical, thermal, surface morphology and rheological were performed using cast extruded PBAT/PHBV-based composite films. Comprehensive characterizations suggested that cast extruded PBAT/PHBV with 5 wt% silane-treated starch (S-t-Starch) composites exhibited 91 and 82 % improvement in oxygen and water vapor barrier, respectively, compared to PBAT film. The increment in % crystallinity (as supported by DSC analysis) of PBAT/PHBV/5%S-t-Starch composite due to the silane component is one of the reasons for barrier improvement. The other reason was the improved interfacial adhesion between matrix and S-t-Starch particles (as supported by SEM analysis), which restricted the mobility of the polymer chains. The elongation at break (%EB) of the cast extruded PBAT/PHBV/5%Starch film was slightly improved from 536 to 542 % after silane treatment. Hence, the developed polymer composite in this research work can contribute to flexible packaging applications that require improved barrier properties.

A field study was conducted at Horticultural Research Farm, Institute of Agricultural Sciences of Banaras Hindu University, Varanasi, India during summer season of 2017-2018 to test the sole effect of phyto-hormones and micro-nutrients on growth of brinjal (Solanum melongena, L.). The thirteen treatments having six different concentration of phytohoromnes viz., T1 (20 ppm NAA), T2 (40 NAA), T3 (60 ppm NAA), T4 (25 ppm GA3), T5 (50 ppm GA3), T6 (75 ppm GA3), and six different concentrations of micronutrients viz., T7 (Boron 0.1%),T8 (Boron 0.2%), T9 (Boron 0.3%), T10 (Zinc 0.1%), T11 (Zinc 0.2%), T12 (Zinc 0.3%) and T13 (control-water spray) for a “Kashi Uttam” cultivar of brinjal were grown under randomized complete block design (RCBD) having three replications. The results findings indicated that treatment T4 (25 ppm GA3) had significant effect on growth parameters, mainly plant height, number of leaves, leaf length, leaf width, crop canopy, number of side roots and main root length. Similarly, yield parameters like number of fruits per plant, fruit weight, fruit yield per plant were found to be significantly superior under treatment T4 (25 ppm GA3). Number of branches per plant, stem diameter, main root length and fruit weight were found superior under treatment T1 (20 ppm NAA). Among the different concentrations of micronutrients treatment T9 (Boron 0.3%) and T12 (Zinc 0.3%) were found to be significant over control. It can be concluded that the phyto-hormones and micro-nutrients can be judiciously used for increasing the growth and yield of brinjal.

This research work focuses on the utilization of waste ocean plastics with waste agro-industrial pyrolyzed biomass to develop complex shaped value-added prototypes through additive manufacturing. Fused Filament Fabrication (FFF)-based three-dimensional (3D) printing of recycled HDPE/PP blends was challenging due to significant warpage-related problems during printing. Reinforcing these blend plastics with fillers played a significant role in the efficient 3D printing of complex-shaped objects. In this research, a blend of these recycled HDPE (70%) (rHDPE) and recycled PP (30%) (rPP) collected from the ocean shores was reinforced with pyrolyzed soy hulls-based biocarbon (20%) to fabricate filaments employed for developing specimens through injection molding as well as FFF-based 3D printing. The design of experiments (DOE) using Taguchi method was performed to determine the optimized 3D printing parameters to obtain the defect-free printed specimens. The results suggested that the injection-molded samples showed better mechanical properties as compared with 3D printed samples. However, an improvement (34%) in Young's modulus of the 3D printed rHDPE/rPP (70/30) blend was observed in comparison with injection-molded counterparts. The 3D printed rHDPE/rPP/20% Biocarbon composite showed an improvement of ∼11 and ∼15% in Young modulus and flex modulus, respectively as compared to rHDPE/rPP. Combining ocean plastics and agro-industrial wastes could generate value-added products that would contribute to the circular economy approach for sustainable product development for different applications such as prototyping and automotive, while helping to protect ocean marine life. Two prototypes, elliptical gears with shaft and spectacle frame, have also been developed by using sustainable recycled HDPE/PP-based composites.

Single-use packaging is a major contributor to municipal solid waste and cause of plastic pollution worldwide, whereas the adoption of biodegradable alternatives is still hampered by significant challenges such as performance shortfalls and inadequate barrier properties. The present work utilizes compostable polymers, namely biobased poly (butylene succinate) (BioPBS) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), combined with hybrid natural fillers to achieve enhanced processability and barrier performances for substituting conventional plastic packaging. BioPBS reinforced with 20 wt.% talc showed improved barrier properties over the neat BioPBS with both the oxygen and water vapor permeabilities improving by about 60%. With the blending of 20 wt.% PHBV, an overall further improvement of about 80% in both properties were achieved. The use of 1% maleic anhydride grafted BioPBS and BioPBS/PHBV-blend coupling agents enhanced the interfacial adhesion of the composites resulting in a consistent improvement of the tensile strength at yield and the oxygen barrier. The incorporation of 5% starch, which could potentially boost the biodegradability of the composites, helped in enhancing the toughness of the material at the expense of lowered barrier properties. Overall, the biocomposites demonstrated comparable mechanical properties to some commodity plastics such as polyolefins while having low oxygen and water permeability, showing great promise for applications in sustainable packaging.

The worldwide demand for additive manufacturing (AM) is increasing due to its ability to produce more challenging customized objects based on the process parameters for engineering applications. The processing of conventional materials by AM processes is a critically demanded research stream, which has generated a path-breaking scenario in the rapid manufacturing and upcycling of plastics. The exponential growth of AM in the worldwide polymer market is expected to exceed 20 billion US dollars by 2021 in areas of automotive, medical, aerospace, energy and customized consumer products. The development of functional polymers and composites by 3D printing-based technologies has been explored significantly due to its cost-effective, easier integration into customized geometries, higher efficacy, higher precision, freedom of material utilization as compared to traditional injection molding, and thermoforming techniques. Since polymers are the most explored class of materials in AM to overcome the limitations, this review describes the latest research conducted on petroleum-based polymers and their composites using various AM techniques such as fused filament fabrication (FFF), selective laser sintering (SLS), and stereolithography (SLA) related to 3D printing in engineering applications such as biomedical, automotive, aerospace and electronics.

Worldwide, improper disposal of plastics is instigating environmental initiatives to combat plastics accumulation of in the environment and the world’s oceans. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) biocomposites with Miscanthus (Misc) fibres and distillers’ dried grains with solubles (DDGS) were studied to ascertain if natural fibres and proteinaceous fillers can improve polyhydroxyalkanoate marine biodegradability. Using ASTM standard D7991-15, the biodegradation of PHBV, PHBV with Misc (15 and 25 wt%) and PHBV with DDGS (15 and 25 wt%) was performed in a simulated marine environment for the first time, as indicated by a literature survey. PHBV/Misc (85/15) and (75/25) biocomposites showed 15 and 25% more biodegradation compared to PHBV, respectively. Proteinaceous PHBV/DDGS (85/15) and (75/25) biocomposites showed 17 and 40% more biodegradation compared to PHBV, respectively. Furthermore, PHBV/Misc (75/25) and PHBV/DDGS (75/25) biocomposites were marine biodegraded in 412 and 295 days, respectively. In conclusion, proteinaceous fillers (DDGS) biocomposites have better marine biodegradability than miscanthus.

Nanobiocomposites with balanced mechanical characteristics are fabricated from poly(lactic acid) (PLA)/poly(butylene succinate) (PBS)blend at a weight ratio of 80/20 in association with varying concentrations of functionalized chitosan (FCH) through reactive extrusion at a temperature of 185 °C. The combined effect of FCH and dicumyl peroxide (DCP) showed insignificant change in tensile strength with a remarkable increase in % elongation at break (∼45%) values. Addition of DCP also caused increase in the molecular weight (Mw ∼ 22%) of the PLA/PBS/1DFCH nanobiocomposite, which is attributed to the cross-linking/branching effect of FCH on the polymers. The interfacial polymer–filler adhesion is also improved, which is observed from the field-emission scanning electron microscopy images of PLA/PBS/1DFCH. For PLA/PBS/1DFCH, the crystallization rate and nucleation density of PLA are increased because of cross-linked/branched structures are developed, which acted as nucleating sites. Therefore, the present work facilitates a simple extrusion processing with a combination of balanced thermal and mechanical properties, improved hydrophobicity (∼27%), and UV-C-blocking efficiency, which draw the possibility for the utilization of the ecofriendly nanobiocomposite in the packing of UV-sensitive materials on a commercial level.

This article demonstrates the synthesis of lactic acid oligomer-grafted-chitosan (OLLA-g-CH), a nanoamphiphilic molecule, by in situ condensation polymerization and its effective use as a nanofiller for improvement in multiple properties of poly(lactic acid) (PLA) films, essential for stringent food packaging applications. Fourier transform infrared spectroscopy (FTIR) analysis shows the presence of amide-ester bond at 1539 cm(-1), which confirms the structural grafting of OLLA chains with chitosan molecules. This nanoamphiphilic OLLA-g-CH molecule act as surfactant containing hydrophilic chitosan head and hydrophobic OLLA tails with average size in the range of ∼2-4 nm. Prepared PLA/OLLA-g-CH bionanocomposite films appear with uniform dispersion of nanoamphiphilic OLLA-g-CH molecules with self-assembled micelles having size as low as ∼20 nm and as high as ∼150 nm with core-shell morphology in PLA matrix. This nanofiller is found very effective toward significant reduction in oxygen permeability (OP) by ∼10-fold due to the reduction in solubility of oxygen molecules and improvement in crystal nucleation density due to availability of nanonucleating sites. Ultimate tensile strength (UTS) of PLA/OLLA-g-CH bionanocomposite films are relatively comparable to that of PLA, however, elongation at break is improved significantly. The onset of thermal degradation of PLA/(OLLA-g-CH) films is also found comparable to that of PLA film. The glass transition temperature (Tg) of bionanocomposites is decreased by more than 18 °C with increase in OLLA-g-CH loading, which indicates the improved plasticization characteristics of PLA matrix. The crystallization kinetics suggest nonthree dimensional truncated spherical structures, which is controlled by the combination of thermal and athermal instantaneous nucleations. POM analysis suggested that the spherulite growth of PLA is improved significantly with the addition of OLLA-g-CH. The reduction in Tg of PLA with improvement in elongation at break and multifold reduction in oxygen permeability offers this bionanocomposite films, a promising candidate for stringent food packaging applications.

The mechanical, thermal and barrier properties of a sustainable PHBV/PBAT blend was investigated under the influence of organically modified nanoclay (0.6, 1.2 and 1.8 wt%) after processing by two different techniques i.e. compression moulding and cast film extrusion. Firstly, a pelletized nanoclay masterbatch was fabricated by blending PBAT with 20% nanoclay using melt extrusion. The masterbatch was used as a reinforcement phase for the PHBV/PBAT blend matrix to fabricate nanocomposite pellets using a melt extrusion process. The prepared PHBV/PBAT/Nanoclay nanocomposite pellets were used to fabricate films using compression moulding and cast film extrusion. The cast extruded PHBV/PBAT nanocomposite films showed improved barrier properties (oxygen and water vapour) as compared to compression moulded films because of the chain orientation during the high-speed stretching. The barrier properties results showed significant improvement of ~79 and ~70% in oxygen and water vapour permeability respectively in cast PHBV/PBAT composite films after adding 1.2 wt% nanoclay, which indicates a good dispersion of nanoclay and strong interfacial adhesion between the matrix and filler. The intercalation/exfoliation of nanoclay in PHBV, as well as at the interface of the PHBV and PBAT blend matrix, was confirmed by transmission electron microscopy (TEM). The % elongation at break (567.6 ± 0.1) of the cast PHBV/PBAT/Nanoclay(1.2%) nanocomposite film was highly improved as compared to that of the PHBV/PBAT blend due to better stress transfer ability as compared to the compression moulded film. The rheological properties also support better dispersion of nanoclay and interaction between the matrix and filler. Hence, the cast extruded nanocomposite film with 1.2% nanoclay is a potential candidate to be used in flexible packaging.

With the objective of giving a new economic life to postindustrial waste poly(lactic acid) (PLA), biocomposites based on recycled PLA were manufactured using conventional melt blending, and the strands produced were successfully used for three-dimensional (3D) printing of American Society for Testing and Materials (ASTM) samples by means of the fused deposition molding (FDM) method. This article further discusses the processing advantages and challenges associated with void formation, anisotropic behavior, and the quality of the 3D printed (3DP) samples in comparison with injection-molded (IM) counterparts. The blends were manufactured containing 30 wt % of recycled PLA in a matrix of virgin PLA. Similarly, blends were also prepared with addition of an epoxy-based chain extender (CE) and as well as with the CE and a reinforcing phase of microcrystalline cellulose (MCC). One of the limitations of recycled PLA in FDM-based 3D printing is its high melt flow due to the reduced molecular weight after recycling, which results in excessive material flow during extrusion, and hence limits its application in FDM-based 3D printing. Consequently, the main effect of the CE, Joncryl, was to control the Melt Flow Index (MFI) of the biocomposites containing the recycled PLA. The addition of CE also resulted in improvement of the impact strength of 3DP samples. In general, the CE in combination with the natural fibers (MCC) allowed the incorporation of postindustrial PLA. Data suggest that more recycled PLA may be incorporated by using this blend combination. In general, owing to the void formation, 3DP samples presented lower values of density (lightweight) and mechanical properties as compared with IM samples. However, the tensile strength, modulus and Izod impact strength of 3DP biocomposites were increased by up to 88%, 127%, and 11%, respectively, by the addition of 5 wt % MCC, as compared with 3DP samples based on postindustrial PLA without additives.

This article demonstrates an elegant approach for the fabrication of high heat-stable PLA using an industrially viable technique i.e. melt extrusion, which is quite challenging due to the higher viscosity of poly(lactic acid) melt. scPLA has been fabricated by melt extrusion of PLLA/PDLA using nano-amphiphilic chitosan (modified chitosan, MCH) which has been synthesized by grafting chitosan with oligomeric PLA via insitu polycondensation of L-lactic acid that possibly increases the molecular surface area and transforms it into nano-amphiphilic morphology and in turn lead to the formation of stereocomplex crystallites. The effect of MCH loading on the structural, morphological, mechanical and thermal properties of PLLA/PDLA have been investigated. The modification of chitosan and formation of stereocomplexation in PLA has been confirmed by FTIR and XRD techniques, respectively. Heat treatment has also laid a significant effect on the stereocomplexation and the degree of crystallinity of stereocomplex crystallites has been increased to ~70% for 1.5 wt % MCH content with the absence of homocrystals. The heat deflection temperature is found to be more than 140 °C for the biocomposite with 1.5% MCH in comparison to ~70 °C for pristine scPLA. The biocomposites display significant improvement in UTS and Young’s modulus.

The present work demonstrates about the formulation of functionalized chitosan (CH-g-OLLA) through the transformation of hydrophilic nature of chitosan into hydrophobic by grafting with oligo(L-lactic acid) (OLLA). The developed CH-g-OLLA is easily soluble in poly(lactic acid) (PLA) matrix, which provides an opportunity towards producing industrially viable nanocomposite films for stringent food packaging and beverages applications. The grafting of OLLA chains is confirmed at NH2 group of chitosan through the presence of two new peaks at 4.2 and 5.1 ppm in 1H–NMR spectra. Various parameters like yield (%), grafting efficiency (%) and percent grafting (%) are calculated as ~51.6, ~40 and ~150%, respectively. Functionalized chitosan has been utilized as nano-filler in PLA matrix to fabricate PLA/CH-g-OLLA nanocomposite films which have compounded successfully by co-rotating twin screw compounder cum cast film extrusion technique (distinctly advantageous over conventional solution casting) at bench scale as well as semi-pilot scale and further demonstrated for its application in the area of food packaging with tailored oxygen barrier properties. Uniform dispersion of spherical aggregates of functionalized chitosan is observed in PLA/CH-g-OLLA nanocomposite films using TEM analysis. A significant reduction up to ~11 °C in glass transition temperature of PLA is observed by adding 5 wt% of nano-filler as a result of plasticization effect, which is an essential property in designing of flexible packages. Mechanical modeling of extruded PLA/CH-g-OLLA films has been performed to compare the experimental values with theoretical results using various mathematical models in which modified foam model, Nielsen model and modified Mitsuishi model demonstrate the best match for Young’s modulus (±0.08), tensile strength (±0.06) and percentage elongation (±0.03), respectively. This may be a significant contribution towards commercialization of such formulation where elegant melt extrusion process of PLA with functionalized chitosan is capable of reducing oxygen permeability up to ~10 folds due to a drastic reduction (~96%) in oxygen solubility.

The theoretical and analyzed data incorporated in this article are related to the recently published research article entitled “Thermal degradation behaviour of nanoamphiphilic chitosan dispersed poly (lactic acid) bionanocomposite films” (http://dx.doi.org/10.1016/j.ijbiomac.2016.11.024) (A.K. Pal, V. Katiyar, 2016) [1]. Supplementary information and data (both raw and analyzed) are related to thermal degradation kinetics and explains various model fitting and is conversional methods, which are used in this research work to enhance the knowledge about degradation behaviour of PLA/CH-g-OLLA bionanocomposite system. Non-isothermal degradation kinetics of such polymeric system was proposed using Kissinger, Kissinger–Akahira–Sunose, Flynn–Wall–Ozawa and Augis and Bennett models to estimate the activation energies (Ea) and R2 values.

In the present study, nano-amphiphilic chitosan termed as chitosan-grafted-oligo l-lactic acid (CH-g-OLLA), is synthesized by microwave initiated insitu condensation polymerization. The synthesized CH-g-OLLA becomes hydrophobic in nature due to chemical bond formation between chitosan backbone and OLLA chains. Further, CH-g-OLLA (30%) bionanocomposite is used as a nanofiller in poly (lactic acid)/chitosan-grafted-oligo l-lactic acid (PLA/CH-g-OLLA) bionanocomposite films. Surface morphology shows a homogeneous dispersion of CH-g-OLLA in the form of spherical aggregates, which vary in the range of ∼20 to 150nm. Non-isothermal degradation kinetics, proposed by Kissinger, Kissinger-Akahira-Sunose, Flynn-Wall-Ozawa and Augis & Bennett models, are utilized to estimate the activation energies (Ea) for PLA, which are 254.1, 260.2, 257.0 and 259.1kJmol-1 respectively. The reduction in Ea values of bionanocomposite films may be elucidated by intermolecular distance and enrichment in chain mobility. The evolved gaseous products like hydrocarbons, carbon dioxide, carbon monoxide and cyclic oligomers are successfully identified with TG-FTIR analysis.

The research work is focused on extraction of chitin from Muga silkworms (MS) and its conversion into chitosan by chemical treatment process. The extracted amount of chitin and chitosan from MS were obtained ∼8 wt % and ∼7 wt %, respectively. Potentiometric titrations, conductometric titrations, elemental analysis, 1H-NMR and FTIR analyses were employed to calculate the degree of deacetylation of chitosan (extracted at 80 oC after 10 h) and found as 77% ± 2, 81% ± 1.8, 82% ± 2.4, 97.77% ± 0.3, and 82% ± 1.8, respectively. The deacetylation process of chitin showed pseudo-first order reaction kinetics and activation energy was estimated as ∼15.5 kJ/mole. The extracted chitosan (at 80 oC after 10 h) showed higher crystallinity and improved thermal stability with respect to chitosan extracted from other marine sources. Subsequently, poly(lactic acid) (PLA) and extracted chitosan dispersed biocomposite films were prepared by solution casting method. Significant dispersion of chitosan (extracted at 80 oC after 10 h) micro-particles were observed in biocomposite films using FESEM analysis. Due to chitosan interaction with PLA, significant reduction in thermal degradation and activation energy was observed during nonisothermal degradation scan of such films using Flynn-Wall-Ozawa and Kissinger-Akahira-Sunose models. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43710.

Various compositions of nontoxic biodegradable poly(lactic acid) (PLA)/chitosan-graft-lactic acid oligomer (CH-g-OLLA) bionanocomposite films were fabricated with a solution casting technique by the dispersal of CH-g-OLLA copolymer at different amounts (1, 3, and 5 wt %) into the PLA matrix. The filler (CH-g-OLLA) was synthesized by an in situ condensation polymerization reaction in a microwave, and the grafting of lactic acid oligomer chains at the C2 position of the chitosan backbone was confirmed by the presence of new peaks at 179.08 and 174.41 ppm in 13C-NMR analysis. The transparency results show the synergic effect of CH-g-OLLA in the form of reduced transparency and excellent blocking capability of UV light. Dynamic mechanical analysis confirmed a reduction in the glass-transition temperature (up to ∼13 °C) with increasing filler concentration; this signified the improvement in the elongation of bionanocomposite films. The rheological studies showed the viscous behavior of the PLA and PLA–CH-g-OLLA bionanocomposite films as the storage modulus values were found to be lower than the loss modulus values over the entire range of angular frequency at 180 °C. Furthermore, a Cole–Cole plot and Han plot described the uniform dispersion of the filler in the PLA matrix, its agglomeration at higher loading, and the structural change between the PLA and PLA–CH-g-OLLA bionanocomposite films. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45546.