Yang Hanhan,Wu Jianmeng,Li Zhenxing,Hao Xinying,Li Hua
Abstract A new biodegradable cellulose derivative-non-isocyanate polyurethane (NIPU) was prepared, and densities, viscosities, and surface tension of NIPU were measured by density bottle method, capillary viscometer and BZY-2 type full automatic surface tension meter respectively from 298.15 to 318.15 K. The results showed that densities, viscosities and surface tension were related to temperature and concentration. The viscosity and surface tension decreased with the increase in temperature at the same concentration; at the same temperature, viscosity and surface tension were positively correlated with concentration. And the experimental data were correlated by the correlation equations of viscosity and temperature, they showed a good agreement with the fitting results of the related equations.
Hongguang Liang,Junwei Wang,Qifeng Li,Chen Liang,Yuelan Feng,Maoqing Kang
The cycloaddition reaction of carbon dioxide (CO2) and bisepoxides is an interesting route for CO2 utilization and green non-isocyanate polyurethane (NIPU) synthesis. In this work, a series of γ-Al2O3 supported ZnBr2 and carbon nitride complex catalysts (Zn–CN/γ-Al2O3) were prepared by a simple thermal polymerization method and applied to the cycloaddition reaction. The results showed that 0.05Zn–CN/γ-Al2O3 exhibited high catalytic activity, over which 91.4% 1,4-butanediol diglycidyl ether (BDODGE) conversion and 98.9% cyclic carbonate selectivity were acquired under solvent and co-catalyst free conditions. The relationship between the structural properties and catalytic performance of Zn–CN/γ-Al2O3 catalysts was studied in detail. It is found that the high surface area and the synergistic effect of Lewis acid–base duality are key factors for the high activity of catalysts. Introducing ZnBr2 could provide acid sites and induce structure change of carbon nitride, which could determine the basic intensity of catalysts. Moreover, based on the elaborate discussions, a plausible catalytic reaction mechanism was proposed.
In the plastic industry, replacing petrochemical-based polymers with naturally occurring bio-polymers (represented by cellulose), is a very promising route to circumvent the plastic pollution issue. However, the implementation of this is severely hindered by the high water affinity and flammability of such materials. Here, a verstile non-isocyanate polyurethane (NIPU) formulation composed of a CO 2 -based cyclic carbonate compound, a reactive amino-functionalized silicone oil concurrently capable of providing water-resistance and a flame-retardant moiety is designed. Compositing it with conventional cellulose paper (cellulose macrofiber network, CMN), a nonflammable and mechanically strong cellulose macrofiber network-based biocomposite (CMN-Biocomposite) can be easily obtained via transcarbamoylation reaction. Other than hydrogen bonding interaction among various components of CMN-Biocomposite, the intermolecular bond exchange mechanism between the dynamic carbamate moiety and hydroxyl of the cellulose is also experimentally and computationally determined as the governing factor for the high tensile strength of up to 57.9 MPa. Additionally, benefiting from the dynamic nature of the carbamate bond, the CMN-Biocomposite's processability and biodegradability outperform most petrochemical-based plastics. The superiority of the proposed synthetic strategy in achieving the long-term carbon neutrality goal by CO 2 fixation and excellent performance for plastic applications make the CMN-Biocomposite a very promising alternative to conventional plastics.
危险品化学品经营许可证（带存储）