عنوان مقاله [English]
Self-curable waterborne polyurethane (WPU) dispersions were prepared via acetone process. The effects of (3-aminopropyl) triethoxysilane (APTES) content as crosslinking agent on the properties of WPUs were investigated. To confirm the polymer structure and the presence of alkoxysilane groups, 1H nuclear magnetic resonance and fourier transform infrared spectroscopy were used. Gel content of the sample containing 10 wt% APTES was reported 90.5% which were revealed highly crosslinking network of the WPU film. Although the particle size went up from 36.5 to 63 nm by introducing 10 wt% APTES, narrow particle size distributions (PDI < 0.2) and the absolute value of zeta potentials greater than 40 mV were obtained. Furtheremore, atomic force microscopy showed that the introduction of siloxane crosslinking increased microphase-separation of the polyurethane films. In the presence of 10 wt% APTES, excellent enhancement in water resistance (water absorption < 5%), mechanical properties (Young’s modulus=420 MPa and tensile strength=46.7 MPa), and thermal stability (Tmax1=321 ºC and Tmax2=407 ºC) made this type of crosslinking highly suitable for WPUs in coating applications.
10.X. Yin, Y. Luo, J. Zhang, Synthesis and characterization of halogen-free flame retardant two-component waterborne polyurethane by different modification. Ind. Eng. Chem. Res. 56 (2017), 1791-1802.
11.Z. Niu, F. Bian, Synthesis and characterization of multiple cross-linking UV-curable waterborne polyurethane dispersions. Iranian Polym. J. 21 (2012), 221-228.
12.H. Sardon, L. Irusta, M. J. Fernández-Berridi, M. Lansalot, E. Bourgeat-Lami, Synthesis of room temperature self-curable waterborne hybrid polyurethanes functionalized with (3-aminopropyl) triethoxysilane (APTES). Polym. 51 (2010), 5051-5057.
13.C. Tao, Z. Luo, J. Bao, Q. Cheng, Y. Huang, G. Xu, Effects of macromolecular diol containing different carbamate content on the micro-phase separation of waterborne polyurethane. J. Mater. Sci. 53 (2018), 8639-8652.
14.H. Zhou, H. Wang, X. Tian, K. Zheng, Q. Cheng, Effect of 3-aminopropyltriethoxysilane on polycarbonate based waterborne polyurethane transparent coatings. Prog. Org. Coat. 77 (2014), 1073-1078.
15.H. Wang, Y. Niu, G. Fei, Y. Shen, J. Lan, In-situ polymerization, rheology, morphology and properties of stable alkoxysilane-functionalized poly (urethane-acrylate) microemulsion. Prog. Org. Coat. 99 (2016), 400-411.
16.H. Sardon, L. Irusta, P. Santamaría, M. Fernández-Berridi, Thermal and mechanical behaviour of self-curable waterborne hybrid polyurethanes functionalized with (3-aminopropyl) triethoxysilane. J. Polym. Res. 19 (2012), 9956-9964.
17.E. Yilgör, E. Burgaz, E. Yurtsever, I. Yilgör, Comparison of hydrogen bonding in polydimethylsiloxane and polyether based urethane and urea copolymers. Polym. 41 (2000), 849-857.
18.Y. Xia, R.C. Larock, Preparation and properties of aqueous castor oil‐based polyurethane–silica nanocomposite dispersions through a sol–gel process. Macromol. Rapid Commun. 32 (2011), 1331-1337.
19.C. Fu, X. Hu, Z. Yang, L. Shen, Z. Zheng, Preparation and properties of waterborne bio‐based polyurethane/siloxane cross-linked films by an in situ sol–gel process. Prog. Org. Coat. 84 (2015), 18-27.
20.L. Lei, Y. Zhang, C. Ou, Z. Xia, L. Zhong, Synthesis and characterization of waterborne polyurethanes with alkoxy silane groups in the side chains for potential application in waterborne ink. Prog. Org. Coat. 92 (2016(, 85-94