Klongklaew Pattamaporn, Khamjapo Phimthong, Sae-Oui Pongdhorn, Jittham Pairote, Loykulnant Surapich, Intiya Weenusarin
National Metal and Materials Technology Center (MTEC), National Science and Technology Development Agency (NSTDA), Klong Nueng, Khlong Luang 12120, Pathum Thani, Thailand.
Polymers (Basel). 2023 Sep 8;15(18):3698. doi: 10.3390/polym15183698.
is a fast-growing tree in the legume family. Its leaf contains a significant amount of protein and is thus widely used as fodder for cattle. To broaden its application in the rubber field, the effects of leaf powder and its extracted products on the cure characteristics and mechanical properties of natural rubber were investigated. The extraction of leaf was carried out by using a proteolytic enzyme at 60 °C. The digested protein was separated from the residue by centrifugation. Both digested protein and residue were then dried and ground into powder, namely digested protein powder and residual powder, respectively, before being characterized by Fourier transform infrared spectroscopy, scanning electron microscope, thermogravimetric analysis, X-ray diffraction, particle size determination, and protein analysis. After being added to natural rubber at 3 parts per hundred rubber, they significantly reduced both the scorch time and the optimum cure time of the rubber compounds, probably due to the presence of nitrogen-containing substances, without a significant sacrifice of the mechanical properties. For instance, the optimum cure time decreased by approximately 25.5, 35.4, and 54.9% for leaf powder, residual powder, and digested protein powder, respectively. Thus, they can be used as green and sustainable fillers with a cure-activation effect in rubber compounding.
是豆科中一种生长迅速的树。它的叶子含有大量蛋白质，因此被广泛用作牛的饲料。为了拓宽其在橡胶领域的应用，研究了叶粉及其提取物对天然橡胶硫化特性和力学性能的影响。叶的提取是在60℃下使用蛋白水解酶进行的。通过离心将消化后的蛋白质与残渣分离。然后将消化后的蛋白质和残渣分别干燥并研磨成粉末，即消化蛋白粉和残留粉，再通过傅里叶变换红外光谱、扫描电子显微镜、热重分析、X射线衍射、粒度测定和蛋白质分析进行表征。以每百份橡胶3份的比例添加到天然橡胶中后，它们显著缩短了橡胶胶料的焦烧时间和最佳硫化时间，这可能是由于含氮物质的存在，同时并没有显著牺牲力学性能。例如，叶粉、残留粉和消化蛋白粉的最佳硫化时间分别减少了约25.5%、35.4%和54.9%。因此，它们可以用作橡胶配方中具有硫化活化作用的绿色可持续填料。
