Analysis of dynamic mechanical, thermal and surface properties of poly(urethane-ester-siloxane) networks based on hyperbranched polyester

• Published in: Journal of non-crystalline solids Vol. 358; no. 23; pp. 3161 - 3169
• Main Authors: Džunuzović, Jasna V., Pergal, Marija V., Poręba, Rafał, Vodnik, Vesna V., Simonović, Branislav R., Špírková, Milena, Jovanović, Slobodan
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier B.V 01-12-2012; Elsevier
• Subjects: Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Dynamic mechanical properties; Exact sciences and technology; Hyperbranched polyester; Materials science; Mechanical and acoustical properties of condensed matter; Mechanical properties of solids; Other materials; Physics; Poly(dimethylsiloxane); Polyurethane network; Specific materials; Thermal expansion; thermomechanical effects and density; Thermal properties; Thermal properties of condensed matter; Thermal properties of crystalline solids; Hyperbranched polyester; Thermal properties; Dynamic mechanical properties; Poly(dimethylsiloxane); Polyurethane network; Dimethylsiloxane polymer; Differential scanning calorimetry; Scanning electron microscopy; Swelling; Ethylene; Thermogravimetry; Mechanical properties; Esters; Dynamic properties; Thermomechanical properties; Contact angle; Urethane; Polyurethanes; Dynamic mechanical analysis; Thermal stability; Deconvolution; Cross-linking; Surface properties; Water absorption
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/j.jnoncrysol.2012.09.013

Six polyurethane networks were synthesized from Boltorn® hyperbranched polyester of the second pseudo generation, α,ω-dihydroxy-(ethylene oxide-poly(dimethylsiloxane)-ethylene oxide) (EO-PDMS-EO) and 4,4′-methylenediphenyl diisocyanate. The effect of the EO-PDMS-EO content on the properties of prepared polyurethanes was investigated by dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), swelling measurements, water contact angle and water absorption. Different techniques (FTIR peak deconvolution, DMTA and SEM) revealed that decrease of EO-PDMS-EO content promotes microphase separation in the synthesized polyurethanes. Samples synthesized with higher EO-PDMS-EO content have more hydrophobic surface and better waterproof performances, but lower crosslinking density. TGA results suggest that thermal stability of the synthesized polyurethane networks in nitrogen is significantly affected by the mutual influence of the crosslinking density and EO-PDMS-EO content. The results obtained in this work indicate that the synthesis of polyurethanes based on hyperbranched polyester and EO-PDMS-EO leads to the creation of networks with good thermal, thermomechanical and surface properties.
► Low PDMS content induced lower thermal stability and higher crosslinking density. ► Microphase separation is enhanced by decreasing PDMS content. ► DMTA revealed existence of two Tgs: of hard and soft segments.