Karolina Villalobos¹, Hider Rojas¹, Rodolfo González-Paz², Daniel Brenes Granados², Jeimmy González-Masís², José Vega Baudrit^1,3, Yendry Regina Corrales-Ureña^1*

Journal of Renewable Materials, Vol.5, No.3-4, pp. 189-198, 2017, DOI:10.7569/JRM.2017.634109

Abstract Because starch is a biodegradable polymer with low cost and wide availability it is an attractive material for producing edible films for fruits. Films produced with pure starch have the disadvantage of being fragile. To overcome this issue, propolis nanoparticles were used as a novel plasticizer. Mechanical, thermal and morphological properties of the films containing 0.5, 1 and 3 wt.% propolis nanoparticles were evaluated. The best performance was obtained using 0.5 wt.% propolis, increasing the Young’s modulus and decreasing the glass transition temperature (Tg), showing their plasticizing effect. The results of scanning electron microscopy (SEM) and atomic force microscopy (AFM)… More >

Xiaoying Li¹, Xiaoan Nie^1,2*, Jie Chen¹, Yigang Wang¹, Ke Li¹

Journal of Renewable Materials, Vol.5, No.2, pp. 154-164, 2017, DOI:10.7569/JRM.2017.634101

Abstract Cardanol, an agricultural by-product of the industrial processing of cashew, was used to synthesize epoxidized cardanol laurate (ECDL) plasticizer. The target product was characterized using FTIR, 1H NMR and 13C NMR. The plasticizing effect of ECDL substitution for petroleum-based plasticizer dioctyl phthalate (DOP) in soft poly(vinyl chloride) (PVC) was investigated using dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA) and mechanical testing, and compared to PVC incorporated with commercial epoxidized soybean oil (ESBO). When DOP was partially substituted by EDCL, there was a slight increase of 5% in glass transition temperature (Tg) and a maximum increase of 14.55% in the elongation… More >

A. Delgado-Lima, M. C. Paiva^*, A. V. Machado

Journal of Renewable Materials, Vol.5, No.2, pp. 145-153, 2017, DOI:10.7569/JRM.2017.634104

Abstract Cellulose acetate (CA) is produced from a natural polymer and presents excellent properties, finding applications in a variety of areas. Unlike cellulose, CA is melt processable and may be molded into parts and formed into fibers or films. In this context, the production of conductive CA composites that may be processable and integrated into parts to provide specific functionalities is an area of increasing interest. The present work aims to prepare electrically conductive composites based on CA and carbon nanotubes (CNTs) by melt mixing. The nanocomposites were produced with pure and pyrrolidine-functionalized nanotubes, using a batch mixer and a twin-screw… More >

A. Ramírez-Jiménez^1*, S. Hernández López¹, E. Bucio², E. Vigueras Santiago¹

Journal of Renewable Materials, Vol.5, No.2, pp. 132-144, 2017, DOI:10.7569/JRM.2016.634138

Abstract Epoxidized linseed oil (ELO) was synthesized and functionalized with propargylamine (PA) or 3-ethynylaniline (EA) and the products were crosslinked to obtain the diacetylene-functionalized epoxidized linseed oil polymers which were used as matrices in the preparation of the composites with multiwalled carbon nanotubes (MWCNTs). Electrical resistance at percentages between 4 and 20 wt/wt% of filler was measured and the percolation threshold was calculated, obtaining 1.2 and 1.7% for the composites with EA and PA respectively. Low critical concentration evidenced a good dispersion of the MWCNTs without necessity of any modification. The final products were used in the sensing of acetone, chloroform… More >

M. Himabindu¹, K. Kamalakar², MSL Karuna², Aruna Palanisamy^1*

Journal of Renewable Materials, Vol.5, No.2, pp. 124-131, 2017, DOI:10.7569/JRM.2016.634137

Abstract Rigid polyurethane biofoams were prepared from karanja polyol which was derived by ring-opening reaction of epoxidized karanja oil. The polyol, which had a hydroxyl value of 186 mg KOH/g, was thoroughly characterized and the structure confirmed by spectral techniques. The foam formulations were developed to achieve shrinkage-free foams with water used as the blowing agent. The resulting foams were characterized for their mechanical properties like density, compression strength and flexural strength. The densities and mechanical properties, such as compression and flexural strength, varied with the amount of methylene diphenyl diisocyanate (MDI) for a fixed amount of polyol and other additives… 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 >

Elena Fortunati^1*, Francesca Luzi¹, Chiara Fanali², Laura Dugo², Maria Giovanna Belluomo², Luigi Torre¹, José Maria Kenny¹, Luca Santi³, Roberta Bernini³

Journal of Renewable Materials, Vol.5, No.2, pp. 81-95, 2017, DOI:10.7569/JRM.2016.634132

Abstract Hydroxytyrosol (HTyr), a biophenol found in extra-virgin olive oil or olive oil by-products, well known for its strong antioxidant activity, was used as active ingredient for poly(vinyl alcohol) (PVA) matrix to develop film formulations by solvent casting process. The effect of HTyr on the morphological, thermal stability, optical, mechanical and release properties of PVA were investigated, while water absorption capacity, migration with food stimulants, water vapor permeability and antioxidant properties were tested taking into account the final application as food packaging systems. Morphological investigations evidenced homogeneity of all PVA/HTyr films, while the presence of HTyr clearly accounted for an increase… More >

Louis C. Muller^1*, Sanette Marx¹, Hermanus C.M. Vosloo²

Journal of Renewable Materials, Vol.5, No.1, pp. 67-80, 2017, DOI:10.7569/JRM.2016.634130

Abstract This work reports a study of polyol synthesis through liquefaction of technical lignins in crude glycerol by means of 1H and 31P NMR spectroscopy. The polyols are intended for preparation of polyurethane foam; thus, it is important to know how different lignin types as well as crude glycerol influence and contribute to the final polyol hydroxyl contents. Polyols prepared from organosolv lignin, kraft lignin and lignosulphonate had hydroxyl numbers suitable for rigid foam of 435, 515 and 529 mgKOH/g, respectively. The polyols differed in composition with glycerol, showing significant variation. During liquefaction the glycerol content was mostly reduced through bonding… More >

Ananda S. Amarasekara^*, Muhammad A. Hasan, Eve Larkin

Journal of Renewable Materials, Vol.5, No.1, pp. 62-66, 2017, DOI:10.7569/JRM.2016.634129

Abstract Condensation polymerization of renewable resources-based monomers, 4-ketopimelic acid and glycerol, were studied using two different catalysts; p-toluenesulfonic acid and Sb2O3. The highest polymer yield of 96% was achieved by using a 3:4 mole ratio mixture of 4-ketopimelic acid and glycerol, with Sb2O3 (0.5 mol% relative to 4-ketopimelic acid) as catalyst and heating at 23–210 °C, under N2 for 1 h; then 210 °C, vacuum, 12 h. The poly(4-ketopimelic acid-glycerol) formed is insoluble in all common organic solvents and is shown to contain a branched polymeric structure with ketal and ester links by using FT-IR, 1H and 13C NMR spectroscopy. More >

M. Thébault^1,2, A. Pizzi1^3*, F.J. Santiago-Medina¹, F.M. Al-Marzouki³, S. Abdalla³

Journal of Renewable Materials, Vol.5, No.1, pp. 21-29, 2017, DOI:10.7569/JRM.2016.634116

Abstract Isocyanate-free polyurethane resins biosourced to a very high percentage level were prepared by the reaction of aminated mimosa tannin extract with commercial mimosa tannin extract prereacted with dimethyl carbonate. The reaction took place with ease at ambient temperature. Indications were that the polyurethanes obtained formed a hard film when cured at a temperature higher than 100 °C. Furthermore, the carbohydrate fraction of the tannin extract also appeared to be carbonated and reacted to generate isocyanate-free polyurethane linkages with the aminated tannins. This indicated that not only the polyphenolic fraction of the tannin extract, but also its other major component, can… More >