Search results for "plastic"
showing 10 items of 7296 documents
Comparative analysis of production and purification of homo- and hetero-polysaccharides produced by lactic acid bacteria
2013
2 figuras, 2 tablas
Directed Assembly of Cellulose Nanocrystals in Their Native Solid-State Template of a Processed Fiber Cell Wall
2021
Funding Information: I.S. thanks The Academy of Finland (grant no. 300364) for funding this work. C.D. acknowledges funding from FAPESP (grant 13/07932‐6). P.A.P. thanks the Emil Aaltonen Foundation and Academy of Finland (grant no. 315768) for funding and ESRF for beamtime at beamline D2am (experiment 02‐01‐885). Rita Hatakka is acknowledged for her assistance with the GPC measurements. Work of M.L. was supported by the Jane and Aatos Erkko Foundation. The work is a part of the FinnCERES Bioeconomy ecosystem. Publisher Copyright: © 2021 The Authors. Macromolecular Rapid Communications published by Wiley-VCH GmbH Copyright: Copyright 2021 Elsevier B.V., All rights reserved. Nanoparticle ass…
Green Composites Based on Hedysarum coronarium with Outstanding FDM Printability and Mechanical Performance
2022
The addition of natural scraps to biodegradable polymers has gained particular interest in recent years, allowing reducing environmental pollution related to traditional plastic. In this work, new composites were fabricated by adding 10% or 20% of Hedysarum coronarium (HC) flour to Poly (lactic acid) (PLA). The two formulations were first produced by twin screw extrusion and the obtained filaments were then employed for the fabrication of composites, either for compression molding (CM) or by fused deposition modeling (FDM), and characterized from a morphological and mechanical point of view. Through FDM it was possible to achieve dense structures with good wettability of the filler that, on…
Strength of cellulosic fiber/starch acetate composites with variable fiber and plasticizer content
2014
In this experimental study, the performance of injection-molded short flax and hemp fibers in plasticized starch acetate were analyzed in terms of strength. Parameters involved in the analysis are a variable fiber and plasticizer content. The measured strength of the composites varies in the range of 12–51 MPa for flax fibers and 11–42 MPa for hemp fibers, which is significantly higher than the properties of the unreinforced starch acetate matrix. The micro-structural parameters used in modeling of composite strength were obtained from optical observations and indirect measurements. Some of these parameters were qualitatively verified by X-ray microtomography.
Biochar Particles Obtained from Agricultural Carob Waste as a Suitable Filler for Sustainable Biocomposite Formulations
2022
In the context of sustainable and circular economy, the recovery of biowaste for sustainable biocomposites formulation is a challenging issue. The aim of this work is to give a new life to agricultural carob waste after glucose extraction carried out by a local factory for carob candy production. A pyrolysis process was carried out on bio-waste to produce biofuel and, later, the solid residual fraction of pyrolysis process was used as interesting filler for biocomposites production. In this work, biochar particles (BC) as a pyrolysis product, after fuels recovery of organic biowaste, specifically, pyrolyzed carobs after glucose extraction, were added on poly(butylene-adipate-co-terephthalat…
Conifer needles as thermoplastic composite fillers: structure and properties
2016
This study describes the properties of thermoplastic polymer composites based on polyethylene (of low and high density) and ethylene-propylene copolymers using various types of conifer needles (pine, spruce, fir, and cedar) as fillers. For the needles, thermogravimetric analysis (TGA) and TGA/Fourier transform infrared spectroscopy (TGA/FTIR) were performed to investigate their structures and thermal resistance, as required for the composite processing methods. Moreover, structural differences were studied for the analyzed fillers and composite materials (FTIR). The results were compared with the values obtained for composites with conifer wood flour. Composites with conifer needles (pine) …
Toward the Decarbonization of Plastic: Monopolymer Blend of Virgin and Recycled Bio-Based, Biodegradable Polymer.
2022
Decarbonization of plastics is based on two main pillars: bio-based polymers and recycling. Mechanical recycling of biodegradable polymers could improve the social, economic and environmental impact of the use of these materials. In this regard, the aim of this study was to investigate whether concentrations of the same recycled biopolymer could significantly affect the rheological and mechanical properties of biodegradable monopolymer blends. Monopolymer blends are blends made of the same polymers, virgin and recycled. A sample of commercially available biodegradable blend was reprocessed in a single-screw extruder until two extrusion cycles were completed. These samples were exposed to gr…
Photo-Oxidative and Soil Burial Degradation of Irrigation Tubes Based on Biodegradable Polymer Blends
2019
: Irrigation tubes based on biodegradable polymers were prepared via an extrusion-drawing process by Irritec and compared to conventional pipes made of high-density polyethylene (HDPE). A commercial polylactide/poly (butyleneadipate-co-butyleneterephthalate) (PLA/PBAT) blend (Bio-Flex®
Cajal–Retzius and Subplate Cells
2013
The laminar and columnar organization of the mature cerebral cortex is determined by a variety of early developmental processes. Two distinct populations of early generated preplate neurons play key roles in corticogenesis. Cajal–Retzius neurons, located in the marginal zone (later layer I), control the formation of neocortical layers by releasing the extracellular matrix protein reelin, which serves as a guiding signal for migrating neurons. Subplate neurons in the lower neocortical layer play an active role in transient synaptic circuits and influence early cortical plasticity and the maturation of the columnar architecture. Both neuronal cell populations serve as transient synaptic targe…
Triterpenoid saponins from Polycarpaea corymbosa Lamk. var. eriantha Hochst.
2013
Abstract Four triterpenoid saponins (1–4) were isolated from Polycarpaea corymbosa Lamk. var. eriantha Hochst along with the known apoanagallosaponin IV (5). Their structures were elucidated by spectroscopic data analysis. Among the compounds 1, 3–5 which were evaluated for their cytotoxicity against three tumor cell lines (SW480, DU145 and EMT6), compound 1 exhibited cytotoxicity with IC50 values ranging from 4.61 to 22.61 μM, which was greater than that of etoposide. Compound 2 was tested only against SW480 and a cardiomyoblast cell line (H9c2), and was inactive.