Effect of Hard Segment Molecular Weight on Concentrated Solution and Bulk Properties of Ether Based Thermoplastic Polyurethanes

Lem, K. W.; Haw, Jung Rim; Curran, Seamus A.; Sund, S.; Brumlik, Charles J.; Song, Gwang-Seok; Lee, D. S.

doi:10.13189/nn.2013.010110

Cited by 6 publications

(2 citation statements)

References 15 publications

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“…Notably, it was observed that when hard segments were present at high concentrations, the diffraction peaks observed were in the range of 2θ = 11.12 • . Consequently, the degree of crystallinity of these polymers (Table 2) was mainly due to the soft segments, which provided more freedom to hard segmental arrangements and enhanced the orientation of the crystallization [20,21]. The measurement of contact angles enabled us to calculate hydrophilicity/hydrophobicity by using diiodomethane and double-distilled water.…”

Section: X-ray Diffraction Studies (Xrd)mentioning

confidence: 99%

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

et al. 2021

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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.

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Section: X-ray Diffraction Studies (Xrd)mentioning

confidence: 99%

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

et al. 2021

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“…However, the hardness of polyurethane gel mentioned in the literature is high for gel pad and seat cushion applications. Besides, many studies have reported only the effect of hard segment content on the thermal and mechanical properties of polyurethane gel [8][9][10]. The effect of a soft segment on the properties of polyurethane gel at low NCO/OH ratio has not been paid enough attention to those studies.…”

Section: Introductionmentioning

confidence: 99%

Influence of Temperature, Time and Crosslinking Agent on Structure and Properties of Polyurethane Gel

Pongmuksuwan

Harnnarongchai

Katabunyanont³

2020

KEM

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Polyurethane (PU) gel was synthesized based on methylene diphenyl diisocyanate (MDI) and polyols corporation with 1,1,1-Tris(hydroxymethyl)propane (TMP) as a crosslinking agent. The chemical structure of synthesized polyurethane gel was investigated using Fourier-transform infrared spectroscopy (FTIR). The effects of curing temperature, curing time, and crosslinking concentration on the degree of swelling, gel content and hardness of polyurethane gel are investigated. In addition, the crosslink density and average molecular weight between crosslinking points were determined using the Flory-Rehner equation. The results revealed that the curing temperature had more pronounced effect on degree of swelling and gel content than curing time. As the curing temperature increased the degree of swelling and gel content in polyurethane gel increased. Curing time seem to have a complicated effect on crosslink density and average molecular weight between crosslinking points. The hardness of polyurethane gel tends to increase with increasing crosslinking concentration and curing time.

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Different approaches for creating nanocellular TPU foams by supercritical CO2 foaming

et al. 2017

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Effect of Hard Segment Molecular Weight on Concentrated Solution and Bulk Properties of Ether Based Thermoplastic Polyurethanes

Cited by 6 publications

References 15 publications

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

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

Influence of Temperature, Time and Crosslinking Agent on Structure and Properties of Polyurethane Gel

Different approaches for creating nanocellular TPU foams by supercritical CO2 foaming

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