Recently, the research team of Zhu Mingqiang of Northwest A&F University has made a new breakthrough in the development and research of functional materials of Eucommia ulmoides gum, increased the extraction purity of Eucommia ulmoides gum to more than 99.0%, and calculated the condition value of good compatibility between Eucommia ulmoides gum and nitrile rubber and natural rubber, and developed a green and efficient electromagnetic screen film based on Eucommia ulmoides gum, which brings good news to the development of China’s high-end rubber industry. The results were published in Biomacromolecules International and Industrial Crops and Products, respectively.
Eucommia ulmoides leaves, skins and seeds.
As a new type of natural rubber, Eucommia ulmoides rubber is one of the world’s most promising high-quality natural rubbers in addition to clover rubber. The unique rubber-plastic duality of Eucommia ulmoides gum makes its application prospects in the fields of thermoplastic, thermoelastic and high elasticity functional materials and engineering materials increasingly prominent, and the national economy and national defense industry have put forward urgent needs for Eucommia ulmoides gum in terms of output, quality and performance.
In view of the problems of high cost, low efficiency, poor purity, and solvent pollution in the traditional extraction of Eucommia ulmoides gum, researcher Zhu Mingqiang’s team established a full-component analysis method based on Eucommia ulmoides gum and lignocellulose in gum-containing organs for the first time, systematically analyzed the composition and content of Eucommia ulmoides gum and lignocellulose in leaves, skins and seeds, and proposed a new way for the clean extraction of Eucommia ulmoides gum by green eutectic solvent coupled with biological method.
Schematic diagram of the new technology for the clean extraction of eucommia ulmoides gum by eutectic solvent coupled biological method developed by Zhu Mingqiang’s team. (All photos are provided by the research group)
It was found that eutectic solvents could effectively dissociate lignin and hemicellulose components from seed husk cell walls, promote cellulose enzymatic hydrolysis, and improve the separation efficiency of Eucommia ulmoides gum. Compared with the traditional extraction methods of Eucommia ulmoides gum such as mechanical grinding and alkali treatment, the extraction efficiency of Eucommia ulmoides gum was greatly improved, and the yield and purity of Eucommia ulmoides gum reached more than 91.0% and 99.0%, respectively. At the same time, value-added components such as nanolignin and fermentable sugar can be obtained during the treatment process.
Based on the clean and efficient extraction of Eucommia ulmoides gum from the upstream, the research team used molecular dynamics methods to predict the compatibility of Eucommia ulmoides gum with nitrile rubber, and Eucommia ulmoides gum with natural rubber. The results showed that when the content of Eucommia ulmoides gum was less than 50%, Eucommia ulmoides gum and nitrile rubber had good blending properties at 398 Kelvin, and Eucommia ulmoides gum and natural rubber had good blending properties at 350 Kelvin. Therefore, the team proposed a vulcanization process for the blending of Eucommia ulmoides gum and nitrile rubber rubber rubber or natural rubber. It is found that compared with traditional rubber products, the rubber compound obtained by the blended vulcanization process has better aging resistance, flexural resistance, wear resistance and hydrophobicity.
Taking advantage of the excellent properties of Eucommia ulmoides gum, the team combined with the self-created curing technology system, using magnetic filler – manganese-zinc ferrite hollow microspheres and conductive filler – superconducting carbon black, through the hot pressing process to develop a green and high-efficiency electromagnetic screen film based on Eucommia ulmoides gum that takes into account the wear resistance, hydrophobicity and corrosion resistance, and its electromagnetic interference shielding efficiency is greater than 80 decibels. By means of complex permeability, complex permittivity and electromagnetic interference shielding efficiency calculation, the team revealed that the material is dominated by dielectric loss and synergistically used by magnetic loss for electromagnetic interference shielding mechanism.
The above research results provide technical support for the clean, efficient and large-scale extraction and separation of Eucommia ulmoides gum, and provide theoretical support for the development of multi-functional electromagnetic interference shielding products in new applications such as new energy vehicles, radar signal shielding, and flexible wearable devices using Eucommia ulmoides gum as the polymer matrix. (Source: China Science News, Jin Jun, Yan Tao)
Related Paper Information:https://doi.org/10.1016/j.ijbiomac.2023.127221
