Semerdjieva IB¹, EP Yankova-Tsvetkova²

Phyton-International Journal of Experimental Botany, Vol.86, pp. 318-324, 2017, DOI:10.32604/phyton.2017.86.318

Abstract Scanning electron microscope (SEM) study of the pollen and seed morphology of Peganum harmala L. and Zygophyllum fabago L. (Zygophyllaceae), in native Bulgarian populations, was carried out. Additionally, a light microscope (LM) investigation on pollen grains was made in order to elucidate the peculiarities of the major parameters of pollen surface and size. It was established that pollen grains in Z. fabago are pantoporate. Exine ornamentation is reticulate. The pollen grains of P. harmala are oblate, spheroidal, elongated, oval in shape, colporate, exine striato-rugulate. The seeds of P. harmala are oblong-oval and slightly flattened at the side (incorrect tetrahedral to More >

Castañón-Nájera G¹, L Latorunerie-Moreno², YA Gálvez Muñoz³

Phyton-International Journal of Experimental Botany, Vol.86, pp. 290-295, 2017, DOI:10.32604/phyton.2017.86.290

Abstract Among the different types of abiotic stresses, water is the most damaging for crops. In the current research, the effect of water stress, induced with Polyethylene Glycol 8000 (PEG8000) and Sodium chloride (NaCl) solutions, was studied in maize genotypes. A randomized block design (RBD) with a factorial arrangement and four replications of 25 seeds each was used. The studied maize genotypes were RC₂C39, RC₂C51 (wild varieties of the State of Tabasco backcrossed with the endogamic line CML247 of the International Center for the Improvement of Maize and Wheat), wild Tamulte, VS536, and Asgrow 7573 hybrid, study… More >

Iqbal A¹, MA Iqbal¹, A Iqbal¹, Z Aslam¹, M Maqsood¹, Z Ahmad², N Akbar¹, HZ Khan¹, RN Abbas¹, RD Khan¹, G Abbas¹, M Faisal¹

Phyton-International Journal of Experimental Botany, Vol.86, pp. 84-88, 2017, DOI:10.32604/phyton.2017.86.084

Abstract Seed inoculation with bacterial species has the potential to increase yield and agro-qualitative attributes of forage crops. This study determined the response of forage maize to three plant growth promoting rhizobacteria [PGPR1 (Azotobacter chroococcum), PGPR2 (Pseudomonas flourescens) and PGPR3 (Bacillus megaterium)] inoculated individually and in different combinations (PGPR1+2, PGPR1+3, PGPR2+3 and PGPR1+2+3). A non-inoculated treatment was kept as a control. We used a completely randomized block design with four replicates. The PGPR1+2+3 treatment showed an outstanding performance by improving yield attributes, green forage yield, dry matter biomass, crude protein and total ash. The same treatment gave the lowest More >

M. Kirpluks^1*, D. Kalnbunde¹, Z. Walterova², U. Cabulis¹

Journal of Renewable Materials, Vol.5, No.3-4, pp. 258-270, 2017, DOI:10.7569/JRM.2017.634116

Abstract In this study, polyols with high average functionality were synthesized from a renewable resource, rapeseed oil, as raw material for rigid PU foam production. A well-known method of rapeseed oil fatty acid double bond epoxidation was used to introduce oxirane rings into rapeseed oil structure. The temperature influence on epoxidation reaction conversion rate was studied by volumetric and FTIR spectra analysis. After epoxidation of rapeseed oil, an oxirane ring-opening reaction was carried out to obtain high functionality polyols. Diethylene glycol, a conventional oxirane ring-opening reagent, was compared to amine-based polyfunctional alcohols, diethanolamine and triethanolamine. The 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 More >

Piotr Rojek², Mirta I. Aranguren¹, Aleksander Prociak², Mirna A. Mosiewicki^1*

Journal of Renewable Materials, Vol.4, No.4, pp. 266-274, 2016, DOI:10.7569/JRM.2016.634113

Abstract Solid biobased polyurethanes (PUs) were prepared from a rapeseed oil-based polyol (ROPO) synthesized by epoxidation reaction followed by oxirane ring-opening with diethylene glycol. The reference material was modified by replacement of the ROPO with glycerol in different proportions and also by addition of commercial microcellulose (MC). The curing process of the reactive mixtures was monitored by rheological measurements and the analysis showed that both MC and glycerol increase the time of crossover between storage and loss modulus (liquid to solid transition in the response at 1 Hz). The completely cured polyurethanes were characterized by physical, More >

Karina Cruz-Aldaco¹, Erika Flores-Loyola², Cristóbal Noé Aguilar-González¹, Nuria Burgos³, Alfonso Jiménez^3*

Journal of Renewable Materials, Vol.4, No.3, pp. 178-184, 2016, DOI:10.7569/JRM.2016.634107

Abstract The use of vegetable oils to replace fossil feedstock has become an area of opportunity and a priority for study in the field of polymer science. Vegetable oils are considered as renewable resources with high potential, low cost and full availability. The aim of this study is the synthesis of biobased polyols from cottonseed oil (Gossypium barbadanse) and corn oil (Zea mays) as feedstock. Their synthesis was successfully performed, as can be concluded from the determination of their hydroxyl index as well as the structural and thermal characterization carried out in this work. Polyurethanes from More >

Anda Fridrihsone-Girone

Journal of Renewable Materials, Vol.3, No.1, pp. 28-33, 2015, DOI:10.7569/JRM.2014.634136

Abstract This study assesses present preliminary Life Cycle Inventory for rapeseed oil polyols suitable for the production of polyurethane, which is one of the most widely used polymer materials. Due to growing environmental problems, the polyurethane industry is seeking bio-based raw materials. A study was carried out for rapeseed oil triethanolamine polyol developed at Latvian State Institute of Wood Chemistry. The cradle-to-gate study was carried out with functional unit of 1 kg rapeseed oil polyol synthesized in a scaled-up pilot reactor. The results show that at the midpoint level the production of rapeseed oil has the More >

Sławomir Michałowski, Aleksander Prociak^*

Journal of Renewable Materials, Vol.3, No.1, pp. 14-18, 2015, DOI:10.7569/JRM.2014.634131

Abstract This article describes the effects of the modifi cation of polyurethane system with rapeseed oil-based polyol on the cell structure and physical-mechanical properties of conventional fl exible polyurethane foams. The foams were prepared by substituting a part of the petrochemical polyether-polyols mixture with the bio-polyol based on rapeseed oil. Selected physical-mechanical properties of these foams were examined and compared to the properties of reference foam. The properties such as apparent density, resilience, comfort factor and stress-strain characteristics were analyzed in compression tests. It was found that the modifi cation of polyurethane formulation with rapeseed oil-based More >

Tamara Calvo-Correas¹, Mirna A. Mosiewicki², M. Angeles Corcuera¹, Arantxa Eceiza¹, Mirta I. Aranguren^2,*

Journal of Renewable Materials, Vol.3, No.1, pp. 3-13, 2015, DOI:10.7569/JRM.2014.634132

Abstract Rigid polyurethane foams were synthesized by using a vegetable oil-based polyol and 4,4-diphenylmethane diisocyanate prepolymer as the majority of reactives,. The polyol was produced by hydroxylation of crude linseed oil with performic acid generated in situ by the reaction of hydrogen peroxide and formic acid. The characterization by FTIR, H1 NMR, iodine and hydroxyl values of the polyol and its comparison with the original linseed oil supports the success of the reaction. The reference foam was subsequently modifi ed by substituting part of the linseed oil polyol with glycerol, diethylene glycol, and a polyethylene glycol More >