Biodegradable Polyesters Reinforced with Surface-Modified Vegetable Fibers
| Autor: | Lidia Armelao, Elisa Zini, Massimo Baiardo, Mariastella Scandola |
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| Přispěvatelé: | E. ZINI, M. BAIARDO, L. ARMELAO, SCANDOLA M. |
| Rok vydání: | 2004 |
| Předmět: |
Materials Chemistry2506 Metals and Alloys
Surface analysis Materials science Polymers and Plastics Polymers Adipates Polyesters Compression molding Mechanical properties Bioengineering Young's modulus Biofibers Environmental Biomaterials chemistry.chemical_compound symbols.namesake Plasticizers Flax Tensile Strength Composites Biodegradation Environmental Cellulose Citrates Lactic Acid Succinates Biotechnology Ultimate tensile strength Materials Chemistry Fiber Composite material Natural fiber chemistry.chemical_classification Polymer Polyester chemistry Biodegradation symbols Ethylene glycol |
| Zdroj: | Macromolecular Bioscience. 4:286-295 |
| ISSN: | 1616-5195 1616-5187 |
| Popis: | Flax fibers are investigated as reinforcing agents for biodegradable polyesters (Bionolle and poly(lactic acid) plasticized with 15 wt.-% of acetyltributyl citrate, p-PLLA). The composites are obtained either by high temperature compression molding fiber mats sandwiched between polymer films, or by batch mixing fibers with the molten polymer. Fibers in composites obtained by the latter method are much shorter (140-200 microm) than those of the mats (5,000 microm). Flax fibers are found to reinforce both p-PLLA and Bionolle (i.e. tensile modulus and strength increase) when composites based on fiber mats are investigated. Conversely, analogous composites obtained by batch mixing show poor mechanical properties. The observed behavior is attributed to the combined effect of fiber length and fiber-matrix adhesion. If flax fibers with a modified surface chemistry are used, the strength of short fiber composites is seen to improve significantly because the interface strengthens and load is more efficiently transferred. Appropriate surface modifications are performed by heterogeneous acylation reactions or by grafting poly(ethylene glycol) chains (PEG, molecular weight 350 and 750). The highest tensile strength of p-PLLA composites is reached when PEG-grafted flax fibers are used, whereas in the case of Bionolle the best performance is observed with acylated fibers. |
| Databáze: | OpenAIRE |
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