Thermal and mechanical properties of poly(urethane‐imide)/epoxy/silica hybrids

Abstract

Improving properties of polyurethane (PU) elastomers have drawn much attention. To extend the properties of the modified PU composite, here a new method via the reaction of poly(urethane-imide) diacid (PUI) and silane-modified epoxy resin (diglycidyl ether of bisphenol A) was developed to prepare crosslinked poly (urethane-imide)/epoxy/silica (PUI/epoxy/SiO 2 ) hybrids with enhanced thermal stability. PUI was synthesized from the reaction of trimellitic anhydride with isocyanateterminated PU prepolymer, which was prepared from reaction of polytetramethylene ether glycol and 4,4 0 -diphenylmethane diisocyanate. Thermal and mechanical properties of the PUI/epoxy/SiO 2 hybrids were investigated to study the effect of incorporating in situ SiO 2 from silanemodified epoxy resin. All experimental data indicated that the properties of PUI/epoxy/SiO 2 hybrids, such as thermal stability, mechanical properties, were improved due to the existence of epoxy resin and SiO 2 .

Hybrid Alkoxysilane-Functionalized Urethane-Imide-Based Poly(ionic liquids) as a New Platform for Carbon Dioxide Capture

“…The bands at 1780 and 1707 cm –1 are attributed to the asymmetric and symmetric stretching vibration of CO (imide groups), respectively. Therefore, the imide groups were successfully introduced into the PU chain. , The absorption band at 1625 cm –1 corresponds to CO of the urethane group. , After conversion from molecular to ionic material, the bands got wider, indicating that more carbonyl groups participate in H-bonding . The new band at 962 cm –1 (O–Si–O) indicates a reaction between −NCO of PU–imide and −NH 2 of APS .…”

“…The first event corresponds to PUIS and HPILs decomposition and occurs at about 175 °C leading to around 5% mass loss. The mass loss is attributed to water evaporation, DMF, and residual low-molecular-weight monomers . The second event is attributed to urethane linkages decomposition .…”

“…Compare 208 and 358 °C in PUIS-02 to 228 and 385 °C in PUIS-06. This is due to the increase of cross-linking at higher silane content which decreases chain mobility and increases thermal stability. , Ionic PUIS-based materials are less thermally stable than their neutral precursors. The same behavior was reported in other PU-based PILs .…”

DMA testing of epoxy resins: The importance of dimensions

“… Literature values of rubbery modulus data collected using 3pt clamps, grouped by span‐to‐thickness ratios .…”

Bulk Preparation of Radiation Crosslinking Poly (Urethane-Imide)

“…Therefore, the preparation of radiation crosslinking poly(urethane-imide), the same need to import some unsaturated group into its molecular backbone (soft segment or hard segment ) or its chain end, to enhance adiation crosslinking effect. In fact, so far, although preparation research of poly(urethane-imide) made a lot of progress [49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65][66][67], but report closely related with radiation polymerization also not too much. Of course, we can prepare radiation crosslinking poly(urethane-imide) by using introduction of unsaturated bond into its molecular structure, especially hard segment structure, also through double end capping to prepare the radiation crosslinking poly(urethane-imide).…”