Kahina Iggui^1,2,*,†, Mustapha Kaci², Nicolas Le Moigne¹, Anne Bergeret¹

Journal of Renewable Materials, Vol.6, No.3, pp. 288-298, 2018, DOI:10.7569/JRM.2017.634184

Abstract The effects of accelerated photooxidation on the molecular weight and thermal and mechanical properties of Cast PHBV and PHBV/Cloisite 30B (3 wt%) bionanocomposites are investigated herein. Through size exclusion chromatography (SEC) analysis, a significant decrease in both weight and number average molecular weights was observed for all irradiated samples over time, resulting from the chain scission mechanism. Differential scanning calorimetry (DSC) data indicated a decrease in degree of crystallinity and melting temperature after UV exposure, with the appearance of double melting peaks related to the changes in the crystal structure of PHBV. Thermal stability, tensile and thermo-mechanical properties were also… More >

Weijun Yang^1†, Xiaomin Zhao^2†, Elena Fortunati¹, Franco Dominici¹, Jose M. Kenny¹, Debora Puglia^1*, De-Yi Wang^2*

Journal of Renewable Materials, Vol.5, No.5, pp. 423-434, 2017, DOI:10.7569/JRM.2017.634146

Abstract Presented herein is a deep investigation of the fire, mechanical and thermal performances of poly(lactic acid) (PLA)-based nanocomposites, which were obtained by combining cellulose nanocrystals (CNC) with various contents of N,N’-diallyl-phenylphosphoricdiamide (P-AA) via a two-steps masterbatch melt extrusion process (glycidyl methacrylate grafting on PLA and CNC premixing with PLA). Results have shown that the value of the limiting oxygen index (LOI) increased to 28.8% and a V-0 rating in UL94 test was obtained when 2 wt% of P-AA was added in the presence of cellulose nanocrystals (3 wt%). The incorporation of CNC induced a decrease of both PHRR and THR… More >

Liqing Wei¹, Shupin Luo², Armando G. McDonald², Umesh P. Agarwal¹, Kolby C. Hirth¹, Laurent M. Matuana³, Ronald C. Sabo^1* , Nicole M. Stark^1*

Journal of Renewable Materials, Vol.5, No.5, pp. 410-422, 2017, DOI:10.7569/JRM.2017.634144

Abstract Cellulose nanocrystals (CNCs) are renewable and sustainable filler for polymeric nanocomposites. However, their high hydrophilicity limits their use with hydrophobic polymer for composite materials. In this study, freeze-dried CNCs were modified by transesterification with canola oil fatty acid methyl ester to reduce the hydrophilicity. The transesterified CNCs (CNCFE) were compounded with PLA into nanocomposites. CNCFE with long-chain hydrocarbons plays a role as plasticizer. Increasing CNCFE loadings resulted in clear plasticizing effects. Lower Tg and Tm were achieved for CNCFE-based nanocomposites. Plasticizing nanocomposite melt with CNCFE can mitigate the degradation of CNCs during thermal processing. The elongation at break of nanocomposites… More >

Arun Kumar Pradhan^1,2*, Prafulla Kumar Sahoo¹, Pradeep Kumar Rana²

Journal of Renewable Materials, Vol.5, No.5, pp. 371-379, 2017, DOI:10.7569/JRM.2017.634129

Abstract Chitosan grafted with poly(methyl-methacrylate) (PMMA) and adsorbed with kaolin functionalized as bioadhesive was prepared via emulsion polymerization technique and physiochemically characterized as a bone-graft substitute. The so prepared grafted bioactive bone cement (BBC) bionanocomposites (BNCs), chitosan-g-PMMA/kaolin, was characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) analysis, field-emission scanning electron microscopy (FESEM) and thermogravimetric analysis (TGA). The water uptake, retention ability and the nanosize particle arrangement in the polymeric BBC-BNCs were studied along with the mechanical and biodegradation properties. These preliminary investigations of the BNCs will open the door for their use in bioadhesive bone-cement implants in the future. More >

F. Luzi¹, E. Fortunati^1*, A. Jiménez², D. Puglia¹, A. Chiralt², L. Torre¹

Journal of Renewable Materials, Vol.5, No.2, pp. 103-115, 2017, DOI:10.7569/JRM.2016.634135

Abstract Poly(lactic acid) (PLA) based nanocomposites reinforced with 1 wt% of surfactant-modified cellulose nanocrystals (s-CNC) extracted from Posidonia oceanica plant waste and zinc oxide nanoparticles (ZnO NPs) at different concentrations (0.1 and 0.5 wt%) were prepared by solvent casting process. Their thermal, morphological, optical, mechanical and water vapor permeability properties were investigated. Tensile testing showed increased values for strength and deformation at break in PLA based formulations reinforced with s-CNC and ZnO NPs as a consequence of better nanofiller dispersion compared to binary films reinforced only with ZnO NPs. Moreover, the effect of s-CNC and ZnO NPs provoked an improvement of… More >

Jithin Joy^1,2,3, Cintil Jose³, Srirama B. Varanasi⁴, Lovely Mathew P.^2,3, Sabu Thomas², Srikanth Pilla^1,5*

Journal of Renewable Materials, Vol.4, No.5, pp. 351-364, 2016, DOI:10.7569/JRM.2016.634128

Abstract Isora nanofibers (INF) were produced by a combined thermal-chemical-mechanical method from Helicteres isora plant. The resulting fibers were analyzed using transmission electron microscopy and scanning electron microscopy, which showed a network-like structure with a length of 600 nm, width of 50 nm and an aspect ratio of 12. Fourier transform infrared spectroscopy indicated that chemical treatments progressively removed noncellulosic constituents. X-ray diffraction analysis revealed that crystallinity increased with successive chemical treatments. Using the synthesized isora nanofibers, poly(butylene succinate) (PBS)-based biodegradable nanocomposites were prepared. The nanocomposites were processed using a Brabender twin-screw compounder and an injection molding machine. Effects of INF… More >

Jose Luis Orellana, Michael Mauhar, Christopher L. Kitchens^*

Journal of Renewable Materials, Vol.4, No.5, pp. 340-350, 2016, DOI:10.7569/JRM.2016.634126

Abstract Polylactic acid (PLA) is one of the most widely used biodegradable polymers due to the ability to synthesize it economically at industrial scale and its favorable properties for many consumer products. However, the rigid nature of PLA is not desirable for specific applications, requiring the incorporation of effective bioderived additives in order to enhance the PLA toughness and broaden applications. In this work, PLA was modified by graft polymerization of polyacrylic acid (PLA-g-PAA) to increase the hydrophilicity to promote compatibilization of cellulose nanocrystals (CNCs) or high molecular polyethylene glycol (PEG). CNCs were found to act as a nucleating agent for… More >

Juan P. Correa^1,2*, Alejandro Bacigalupe^2,3, Jorge Maggi⁴, Patricia Eisenberg^2,3

Journal of Renewable Materials, Vol.4, No.4, pp. 258-265, 2016, DOI:10.7569/JRM.2016.634117

Abstract Poly(lactic acid)/poly(butylene adipate-co-terephthalate) (PLA/PBAT)-based nanocomposites were prepared by melt blending of PLA and PBAT with 5 wt% of unmodified (Cloisite Na) and modified (Cloisite 30B) montmorillonites. X-ray diffraction (XRD) revealed an intercalated structure in both nanocomposites. The extent of the intercalation was higher for nanocomposites based on modified clays (OMMT) with chemical affinity with the polymer matrix. Rheological measurements have shown an increase in viscosity and a better degree of clay dispersion for nanocomposites containing OMMT. Nanocomposites with OMMT showed lower PBAT separated phase particle size and improvements in thermal stability, mechanical properties and water vapor barrier when compared with… More >

G. Lasko^∗, I. Schäfer^∗, Z. Burghard^†, J. Bill^†, S. Schmauder^∗, U. Weber^∗, D. Galler^‡

Molecular & Cellular Biomechanics, Vol.10, No.1, pp. 27-42, 2013, DOI:10.3970/mcb.2013.010.027

Abstract Owing to the apparent simple morphology and peculiar properties, nacre, an iridescent layer, coating of the inner part of mollusk shells, has attracted considerable attention of biologists, material scientists and engineers. The basic structural motif in nacre is the assembly of oriented plate-like aragonite crystals with a ’brick’ (CaCO₃ crystals) and ’mortar’ (macromolecular components like proteins) organization. Many scientific researchers recognize that such structures are associated with the excellent mechanical properties of nacre and biomimetic strategies have been proposed to produce new layered nanocomposites. During the past years, increasing efforts have been devoted towards exploiting nacre’s structural design principle in… More >

Kunigal N.Shivakumar¹, Shivalingappa Lingaiah², Robert Sadler², Matthew Sharpe²

CMC-Computers, Materials & Continua, Vol.1, No.4, pp. 309-318, 2004, DOI:10.3970/cmc.2004.001.309

Abstract The exfoliation and dispersion of nanoclay (2% by weight) and nanovermiculite (2% by weight) particles in a polymer matrix is analyzed using the Scanning Electron Microscope (SEM) after a low temperature air plasma etch. The plasma etch preferentially removes the polymer to expose the nanoparticles. Both Argon and air have been used as the etching media to study the etching process. SEM analysis illustrate the results of the etching in flat and edge surfaces of both nanoclay (MMT) and nanovermiculite (VMT) filled polymer. Both the MMT and VMT were dispersed using a IKA high shear mixer and a Sonicator. More >