Impact of Macrodiols on the Morphological Behavior of H12MDI/HDO-Based Polyurethane Elastomer

Abstract

In this study, we evaluated the morphological behavior of polyurethane elastomers (PUEs) by modifying the soft segment chain length. This was achieved by increasing the soft segment molecular weight (Mn = 400–4000 gmol−1). In this regard, polycaprolactone diol (PCL) was selected as the soft segment, and 4,4′-cyclohexamethylene diisocyanate (H12MDI) and 1,6-hexanediol (HDO) were chosen as the hard segments. The films were prepared by curing polymer on Teflon surfaces. Fourier transform infrared spectroscopy (FTIR) was utilized for functional group identification in the prepared elastomers. FTIR peaks indicated the disappearance of −NCO and −OH groups and the formation of urethane (NHCOO) groups. The morphological behavior of the synthesized polymer samples was also elucidated using scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques. The AFM and SEM results indicated that the extent of microphase separation was enhanced by an increase in the molecular weight of PCL. The phase separation and degree of crystallinity of the soft and hard segments were described using X-ray diffraction (XRD). It was observed that the degree of crystallinity of the synthesized polymers increased with an increase in the soft segment’s chain length. To evaluate hydrophilicity/hydrophobicity, the contact angle was measured. A gradual increase in the contact angle with distilled water and diiodomethane (38.6°–54.9°) test liquids was observed. Moreover, the decrease in surface energy (46.95–24.45 mN/m) was also found to be inconsistent by increasing the molecular weight of polyols.

Surface Characterization and Anti-Biofilm Effectiveness of Hybrid Films of Polyurethane Functionalized with Saponite and Phloxine B

“…A broad hump was observed in the profile of the XRD pattern of pure PU membrane near 19.5 • (2θ), which relates to the spacing of about 0.45 nm (Figure 3). The shape of the reflection indicates an amorphous phase of the polymer and a low grade of crystallinity [32]. A broad reflection of 2θ ≈ 10-11 • was assigned to a d-spacing of 0.85 nm associated with the reflections of the polymer phase, namely of the planes lying in regions perpendicular to the lamellar surface [33].…”

Adhesion Improvement of Solvent-Free Pressure-Sensitive Adhesives by Semi-IPN Using Polyurethanes and Acrylic Polymers

“…Figure 6 a shows the FT-IR spectra of the HPUs before IPN structure formation; C=O stretching, N-H bending, and C–O stretching peaks of the urethane group were observed at the same position as those of the SPUs. However, the intensity of the peaks attributed to the urethane groups (C=O and N-H) in HPUs was higher than that for SPU-2I [ 32 , 33 , 34 ].…”

“…For the structural characterization of the SPU-6I, SPU-4I, and SPU-2I, FT-IR spectroscopy was performed ( Figure 3 ). The C=O stretching, N-H bending, and C–O stretching peaks from the urethane group of the SPUs were observed at 1680–1740, 1500–1640, and 1100 cm −1 , respectively [ 32 , 33 , 34 ]. As shown in Figure 3 a, as the PPG molecular weight increased from 2000 to 6000, the peak intensities of the N-H and C=O groups decreased for the SPU samples.…”

Synthesis and Study of Morphology and Biocompatibility of Xanthan Gum/Titanium Dioxide-Based Polyurethane Elastomers

“…The crystalline behavior of XTPU samples was calculated by using the crystalline peak intensity of respective samples. The Debye-Scherer (powder) method, applying Bragg’s relation, was used to estimate the d-spacing of various XTPUs [ 37 ].…”

“…The higher molecular weight of macrodiol and xanthan gum provided ordered and compact arrangments of soft and hard phases. However, various factors can be reponsible for phase segregation in PU, such as the diminsions of soft and hard segments, the polarity of groups, the chemical nature, and molecular weight [ 37 , 39 ].…”