Nanostructured composites based on interpenetrated polymer networks. Nonisocyanate polyurethanes based on cyclic carbonates and nanostructured composites. Part II - Статья

Nanostructured composites based on interpenetrated polymer networks. Nonisocyanate polyurethanes based on cyclic carbonates and nanostructured composites. Part II O. Figovsky, D. Beilin, A. Leykin Abstract nanostructured composite polyurethane carbonate Recent advances in chemistry and technology of nonisocyanate polyurethane (NIPU) materials based on cyclic carbonate oligomers are reviewed in this paper. Reaction of the cyclic carbonate and amino groups results in ?-hydroxyurethane fragments with specific properties. Primary attention is given to the hybrid materials that contain epoxy and acrylic compounds, especially materials based on renewable raw materials. Hybrid organic composites comprising of silanes are also considered. An overview of the recent publications in this field is provided with a more detailed description of achievements by the authors and their corporate employees. The use of NIPU materials as coatings, adhesives, and foams is described. Key words: nonisocyanate polyurethanes, cyclic carbonate oligomers, hybrid polymers 1. Hydroxyurethane compounds from renewable plant-based raw materials In contrary to the polymerization of carbonate ring containing monomers, molecules containing multiple cyclic carbonate rings are also available by an addition of carbon dioxide to the appropriate multi-epoxy compounds. The largest class of such reagents is epoxidized vegetable oils or their derivatives like fatty acids or their dimers [35]. The reports on carbonation of epoxidized vegetable oils are in most cases based on similar procedures using comparable catalytic systems and reaction conditions (Table 6 [35]). Table 1 The reaction conditions of carbonation of epoxidized vegetable oils No. Expodized vegetable oil Carbonation condition 1 2 3 1 Soybean Epoxol 7-4 TBAB* (2.5 mol% per epoxy groups) CO2 (5.65 MPa), 22 hr, 140?C 1 2 3 2 Soybean Shanxi Chemical Factory, China TBAB and SnCl4·5H2O (2.5 mol% per epoxy groups) CO2 (high pressure), up to 30 hr, 140?C 3 Soybean (ESO, Vikoflex 7170) Arkema TBAB (5.9 MPa), 46 hr, 140?C 4 Vernonia oil Vertech, Inc TBAB (5.9 MPa), 46 hr, 140?C 5 Soybean, Flexol EPO, Dow Chemical TBAB (1.25-5 mol% per epoxy groups) CO2 (5.65 MPa), 110-180?C 6 Fatty acids dimers from sunflower oil TBAB (3 wt %) CO2 (5MPa up to 18.5 MPa), 60-140?C 7 Soybean oil Paraplex G-62 from CP.Hall Co. TBAB (5 mol% per epoxy groups) CO2 (medium flow), 70 hr, 140?C 8 Soybean oil from Cognis TBAB (3 mol% per epoxy groups) CO2 (1 MPa), 20 hr, 140?C 9 Linseed oil (ELSO from HOBUM Oleo chemical TBAB (3 mol% per epoxy groups) CO2 (1 MPa), 20 hr, 140?C 10 Soybean oil NOPCO Colombiana TBAB (3-7 mol% per epoxy groups) CO2 (continuous flow), 100-140?C. microvawes, 40-70 hr 11 Soybeanoil VIKOFLEX 7170 from Atofina TBAB or TBAOH**CO2 (3.4 MPa), 100?C 12 Cottonseed XinjjlandWulumuqiXinsai Oil & fat Co., Ltd, China TBAB (1.25-6 mol% per epoxy groups) CO2 (1-3 MPa), 100-150?C 13 Soybean oil from Cognis Turkey TBAB, CO2 (0.45 MPa), 12 hr, 110?C 14 Inseed oil (Dehysol B316) from Cognis GmbH TBAB (5 mol% per epoxy groups) CO2 (medium flow), 72 hr, 110?C Authors and their collaborators proposed a new method of producing a hybrid polyhydroxyurethane network comprising of [36]: a) Reacting epoxidized unsaturated fatty acid triglycerides with carbon dioxide in the presence of a catalyst to obtain carbonated-epoxidized unsaturated fatty acid triglycerides, wherein conversion of oxyrane groups to 2-oxo-1,3-dioxolane groups (cyclic carbonate groups) for said carbonated-epoxidized unsaturated fatty acid triglycerides ranges from 35 % to 85 % (Fig.5); b) Mixing and reacting the carbonated-epoxidized unsaturated fatty acid triglycerides with a compound having an amine functionality comprising at least one primary amine group realized at stoichiometric or within nearly balanced stoichiometry; c) Mixing and reacting the product of (b) with a compound having amine functionality comprising at least two primary amine groups realized at excess of an amine-functional compound; d) Mixing the product of (c) with a compound having amino-reactive groups and selected from the group comprising: · Acompound having epoxy functionality, and · A mixture of the compound having epoxy functionality with carbonated-epoxidized unsaturated fatty acid triglycerides, a ratio of the sum of amino-reactive groups to the sum of amine groups being stoichiometric or within nearly balanced stoichiometry; e) Curing the resulting composition at ambient temperature. Fig. 1 Obtaining carbonated epoxidized unsaturated fatty acid triglycerides The proposed method can significantly reduce time of synthesis and improve quality of the final products. Silane-containing and nano-structured hydroxyurethane compounds The concept of generating silica from alkoxysilanes by the sol-gel method within a macromolecular organic phase (in situ) is widely known in the art. The composition is highly curable at low temperatures (approximately 10 - 30 °C) with generating n