Synthesis and characterization of siloxane-based polyurethane elastomers using hexamethylene diisocyanate

Abstract

The present research work was performed to study the properties of siloxane-based polyurethane (SPU) elastomers using aliphatic diisocyanate. SPU samples constituting of hexamethylene diisocyanate, hydroxyl-terminated polybutadiene, and polydimethylsiloxane (PDMS) were synthesized by two-step polymerization technique. Molecular engineering and surface characterization were carried out, and the outcome of the results was discussed. The conventional spectroscopic characterization of the synthesized samples using Fourier transform infrared spectroscopy confirms the existence of the proposed SPU structure. Surface properties of the synthesized material were studied determining the percentage of water absorption and equilibrium of the degree of swelling. It was found that by increasing the mole ratio of PDMS, the synthesized PU samples showed hydrophobic behavior while placing them in water and in dimethylsulfoxide solvent.

Polyurethane synthesis for vascular application

“…Other bonds in the chemical structure of the synthesized polyurethanes are shown in Table 1 . Our results are in agreement with those previously reported by Bai et al ( 2008 ; Zia et al 2014 ).

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Synthesis and characterization of polydimethyl siloxane-based polyurethane elastomers using toluene diisocyanate

“…FTIR spectrum of PDMS has been presented in Figure 2(d) and detailed peak assignment has been presented in our previous study. 22 Some upward peaks can be observed in the spectrum of PDMS and these peaks can be further observed in the spectrum of final PUEs just after the introduction of PDMS with some broadening of peaks because of the change of the environment that strongly support the incorporation of the PDMS in the final material.…”

“…The observed peaks in the FTIR spectrum of HTPB (Figure 2(b)) has been comprehensively discussed elsewhere. 22 By the reaction of TDI and HTPB, isocyanate-terminated PU prepolymer was obtained, and the FTIR spectrum of NCO-terminated PU prepolymer has also been presented in Figure 2(c). It is clearly observed that the signal for the OH groups are not present and that of the intensity of NCO groups has reduced to some extent resulting that isocyanate group has been entirely reacted and a signal for NH units appeared at 3323.6 cm −1 suggesting that PU prepolymer had been formed (Figure 2(c)).…”

“…In a similar study using the aliphatic diisocyanate, the adverse effect has been observed which also support the above-discussed results. 22…”

Eco‐friendly foams of castor oil based‐polyurethane with Artemisia residue fillers for discarded vegetable oil sorption

“…For the wavenumber of 1250 cm −1 , the “spike” in pristine PU can be related to the stretching mode of C‐N structures combined with the stretching mode of N─H structures 84 and the ─CH 2 vibrations 85 . Besides, that disturbance also can relate to the castor oil polyol used in the foam's synthesis, as seen by Alaa et al 87 …”