Intapun Jutharat, Rungruang Thipsuda, Suchat Sunisa, Cherdchim Banyat, Hiziroglu Salim
Faculty of Science and Industrial Technology, Surat Thani Campus, Prince of Songkla University, Surat Thani 84000, Thailand.
Natural Resource Ecology and Management, Oklahoma State University, Stillwater, OH 74078, USA.
Polymers (Basel). 2021 Mar 31;13(7):1109. doi: 10.3390/polym13071109.
The objective of this work was to investigate the influences of Klason lignin as a filler on the thermal stability and properties of natural rubber composites. The modulus and tensile strength of stabilized vulcanizates were measured before and after thermo-oxidative aging. It was determined that lignin filled natural rubber had significantly enhanced thermo-oxidative aging and mechanical properties compared to those of controlled samples. The reinforcement effect of lignin increased stress with lignin loading but it decreased at 20 phr, suggesting that the reinforcement mechanism of lignin was via strain-induced crystallization. The composite samples with 10 phr filler loading had the highest mechanical properties as well as thermo-oxidative degradation resistance. Such a finding could be due to interactions between the Klason lignin filler and natural rubber matrix. Based on the findings in this work, the degradation temperature of Klason lignin occurred at 420 °C. The absorption peaks at wavenumbers 1192 and 1374 cm indicated that C-O stretching vibrations of the syringyl and guaiacyl rings of hardwood lignin existed. It was also found that the Klason lignin-rubber composite containing 10 phr had the highest stress-strain, 100% modulus, and tensile strength, while lignin showed increasing aging resistance of the composite comparable with commercial antioxidant at 1.5 phr. It appears that Klason lignin from rubberwood could be used as a green antioxidant and alternative reinforcing filler and for high performance eco-friendly natural rubber biocomposites.
这项工作的目的是研究克拉森木质素作为填料对天然橡胶复合材料热稳定性和性能的影响。在热氧化老化前后测量了稳定化硫化胶的模量和拉伸强度。结果表明，与对照样品相比，木质素填充的天然橡胶具有显著增强的热氧化老化性能和机械性能。木质素的增强作用随着木质素用量的增加而增加应力，但在20份时降低，这表明木质素的增强机制是通过应变诱导结晶。填料用量为10份的复合样品具有最高的机械性能以及抗热氧化降解性能。这一发现可能是由于克拉森木质素填料与天然橡胶基体之间的相互作用。基于这项工作的发现，克拉森木质素的降解温度为420℃。波数为1192和1374cm处的吸收峰表明存在阔叶树木质素丁香基和愈创木基环的C-O伸缩振动。还发现，含有10份的克拉森木质素-橡胶复合材料具有最高的应力-应变、100%模量和拉伸强度，而木质素在1.5份时表现出与商业抗氧化剂相当的提高复合材料耐老化性的作用。看来，橡胶木中的克拉森木质素可作为绿色抗氧化剂和替代增强填料，用于高性能环保型天然橡胶生物复合材料。
