Nanohybrid polyurethane/functionalized silsesquioxane systems. Part I. Structural investigations using FT-IR and NMR methods

Abstract

Uk³ady nanohybrydowe poliuretan/funkcjonalizowany silseskwioksan Cz. I. BADANIA STRUKTURALNE Z ZASTOSOWANIEM FT-IR I NMR **)Streszczenie -Okreoelono budowê chemiczn¹ uk³adów nanohybrydowych poliuretan/funkcjonalizowany silseskwioksan (PUR/PHIPOSS) otrzymanych metod¹ prepolimerow¹. Na widmach 1 H NMR i 13 C NMR stwierdzono wystêpowanie sygna³ów pochodz¹cych od protonów i atomów wêgla charakterystycznych fragmentów bocznych grup PHIPOSS. Analiza otrzymanych widm elastomerów PUR/PHIPOSS metod¹ ATR-FTIR pozwoli³a na oszacowanie wp³ywu obecnooeci bocznych grup oligosilseskwioksanowych na gêstooeae wi¹zañ wodorowych oraz separacjê fazow¹. Stwierdzono, ¿e stopieñ rozdzia³u faz wzrasta ze wzrostem zawartooeci PHIPOSS. S³owa kluczowe: elastomery uretanowe, funkcjonalizowany silseskwioksan, materia³y nanohybrydowe, spektroskopia ATR-FTIR, spektroskopia NMR. NANOHYBRID POLYURETHANE/FUNCTIONALIZED SILSESQUIOXANE SYSTEMS. Part I. STRUCTURAL INVESTIGATIONS USING FT-IR AND NMR METHODSSummary -A chemical structure of polyurethane/functionalized silsesquioxane (PUR/PHIPOSS) nanohybrid materials obtained by prepolymer method has been determined. In the 1 H NMR and 13 C NMR spectra signals from protons and carbon atoms of the characteristic fragments of the PHIPOSS pendant group have been identified. Analysis of the obtained PUR/PHIPOSS elastomers by ATR-FTIR allowed us to estimate the influence of oligosilsesquioxane side groups on the density of the hydrogen bonds and phase separation. It was found that the degree of phase separation increases with increasing PHIPOSS content.

Synthesis and morphology of rigid polyurethane foams with POSS as pendant groups or chemical crosslinks

“…c, d, and e in the area of 1760–1680 cm −1 . The spectra of PU elastomers in this region show two peaks corresponding to vibrations of free and hydrogen‐bonded carbonyl groups . Here, we may observe only one peak at 1710 cm −1 corresponding to the free ones.…”

“…PUF/OCTA‐POSS (spectrum e) also shows this offset, although to a much lesser extent. This offset may be due to a decrease of the participation of C–O–C groups in the formation of hydrogen bonds . The PHI‐POSS, having iso ‐butyl substituents, facilitates mixing with the amorphous phase and causes a separation of ether groups from amine groups, thus disabling the formation of hydrogen bonds between them.…”

“…Hybrid PU-POSS elastomers have been widely studied in the literature [9][10][11][12][13][14][15][16][17][18] in various macromolecular architectures. On the other hand, hybrid PU foams have been designed in limited cases and patents have been filed, [19] while scientific literature reports are rather scarce.…”

“…On the other hand, hybrid PU foams have been designed in limited cases and patents have been filed, [19] while scientific literature reports are rather scarce. [20] Fourier transform infrared (FTIR) has revealed that in systems with POSS pendent on elastomeric PUs, [16] POSS with one vertex group with double OH functionality and seven isobutyl vertex groups (PHI-POSS) can increase the amount of hydrogen bonds between NH and urethane groups. [16,17] Wide-angle X-ray diffraction (WAXD) showed that in the elastomers, the pendent particles tend to crystallize to some extent, [17] while the crosslinking ones remain highly amorphous, albeit 100-nm sacs may occur at loadings more than 8 wt%.…”

Epoxy Elastomers Modified with Silsesquioxane

“…[3] Many reports published so far discuss methods of preparation and various applications of POSS and other types of silsesquioxanes. [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] The latter have certain specific characteristics which distinguish them from other fillers. Unlike traditional organic compounds, POSS derivatives are non-volatile as well as odourless and may be considered to be environmentally friendly.…”