Understanding the development of interfacial bonding within PLA/wood-based thermoplastic sandwich composites
| Autor: | Andreas Krause, Marc Gaugler, Jan Luedtke, Warren J. Grigsby |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
0106 biological sciences
chemistry.chemical_classification Thermoplastic Materials science 010405 organic chemistry Wood veneer technology industry and agriculture Dynamic mechanical analysis Polymer respiratory system 01 natural sciences 0104 chemical sciences Amorphous solid stomatognathic system chemistry Ultimate tensile strength lipids (amino acids peptides and proteins) Composite material Glass transition Agronomy and Crop Science Softening 010606 plant biology & botany |
| Zdroj: | Industrial Crops and Products. 127:129-134 |
| ISSN: | 0926-6690 |
| DOI: | 10.1016/j.indcrop.2018.10.069 |
| Popis: | Poly(lactic acid) wood veneer sandwich composites have been prepared and tested in situ across a range of PLA processing temperatures to provide new information of bondline morphology and composite strength. Mechanical property analysis revealed no distinctions between use of semi-crystalline or amorphous PLA polymer grades, but greater strength was observed using maple compared to beech wood. Composites also exhibited greater tensile strength when tested below 60 °C compared to >80 °C which was related to PLA softening above its glass transition temperature. Quantification of interfacial strength revealed composites prepared at >160 °C had higher bondline tensile strength than those formed at 140 °C. Microscopy analysis revealed that this higher tensile strength was associated with a thinner bondline and greater PLA migration away from the bondline consistent with a lower melt viscosity. This deeper PLA migration contributed to a better physical interlocking of the PLA matrix within the wood ultrastructure and associated increases in interfacial strength. Complementary DMTA analysis confirmed the thicker PLA bondlines produced at 140 °C when heated above the PLA Tg had a significant reduction in composite strength. In contrast, the thinner bondlines formed at 200 °C, were less influenced by PLA properties and at elevated temperature retained greater storage modulus. |
| Databáze: | OpenAIRE |
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