Preparation and Characterization of Waterborne Hyperbranched Polyurethane-Urea and Their Hybrid Coatings

Abstract

A series of novel waterborne hyperbranched polyurethane-urea (WHBPU) were prepared with different chain extenders (diamine, diol, and siloxane) by a systematic reaction process. Initially, the hyperbranched polyester polyol was prepared by reacting polytetramethyleneglycol (PTMG)-1000 with 2,2-bis(hydroxymethyl) propionic acid (DMPA) in a molar ratio of 1:14 (3rd generation) at 160 °C by one pot synthesis. This was reacted with an adduct of isophorone diisocyanate (IPDI) and DMPA with NCO:OH mole ratio of 1.6:1. Then 50% of free NCO in these prepolymers was reacted with three different chain extenders (diol, diamine and APTES). This reaction mixture was neutralized with triethyl amine and another 50% of free NCO was chain extended with isophorone diamine during water dispersion. The obtained polyester was characterized with Fourier transform-infrared spectroscopy (FT-IR), 1 H and 13 C NMR, respectively. The properties of WHBPU and their hybrid coatings were studied by FT-IR, 1 H NMR, thermogravimetric analyzer (TGA), dynamic mechanical, and thermal analyzer (DMTA), and the contact angle measurement. TGA and DMTA results confirmed that these coatings have good thermal and mechanical properties. The onset degradation temperature of the WHBPU without APTES starts in between 200 and 250 °C, whereas the APTES chain extended WHBPU starts at 250 °C. T g of WHBPU without APTES varies between 106 and 126 °C, while 129 °C for APTES chain extended WHBPU. The conditions for the reproducible preparation of suitable products have been found and optimized. They enable the tuning of their properties according to the intended use. The aim of the prepared WHBPU films is long-term use as thermal and mechanical resistant systems. Along with these property APTES crosslinked system, the hydrophobic silica-rich surface is likely to be inhibited the hybrid films upon exposure to an aqueous environment.

Waterborne polyurethanes: influence of chain extender in ftir spectra profiles

“…On the other hand, the increase in rigid segments content, or in the amount of urethane and urea linkages, led to an increase in the polarity and in the intensity of the lower frequency bands associated to hydrogen interactions, as expected. The bands were shifted to lower wavenumbers with the increasing of NCO/OH ratio, i.e., the amount of urea groups [6]. By comparing the profile of the split bands correspondent to the samples obtained with the three different chain extenders, it is remarkable the influence of urea linkages on mixture of polyols (P 12 ) and variation in the rigid segments content (NCO/OH = 1.9; 2.3 and 3.…”

“…The research focusing on formulations based on both waterborne polyurethane (wPU) and poly(urethane-urea) (wPUU) has been motivated by environmental considerations and also due to the superior properties presented by these resins in comparison to similar solvent-born ones [5][6][7][8][9]. * E-mail: mcd@uerj.br Thermoplastic wPU and wPUU elastomers may be considered as multiblock copolymers of the (A-B)n type, consisting of alternate sequences of soft and hard segments or domains.…”

Synthesis and properties of a novel UV-curable waterborne hyperbranched polyurethane

“…1. [13][14][15] The present paper describes the synthesis and structure-property relationship of a new UV-curable, waterborne, hyperbranched ionomer based on H10 that was characterized by 1 H nuclear magnetic resonance ( 1 H NMR) spectroscopy, and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS). A variety of UV-curable, waterborne dispersions have been synthesized with different content of succinic anhydride and TDI-HPA in H10-based prepolymer.…”

Polydimethylsiloxane and Castor Oil Comodified Waterborne Polyurethane

“…However, some properties of WPU still need to be improved further, such as water and solvent resistance, thermal stability, and mechanical properties. The improvements of these properties have been achieved by copolymerizing or grafting of other polymers, external and internal cross-linking, blending or interpenetrating, polymer network formations, and modifying with nanoparticles [3][4][5][6][7].…”