Effect of soft segment length on properties of hydrophilic/hydrophobic polyurethanes

Lin, Yu–Chen; Chou, Nai‐Kuan; Chen, Kuan-Fu; Ho, Guan-Huei; Chang, Chien Hsin; Wang, Shoei‐Shen; Chu, Shu‐Hsun; Hsieh, K. H.

doi:10.1002/pi.2291

Cited by 30 publications

(16 citation statements)

References 30 publications

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“…It is probably accelerated by the catalytic effect of the derivative compounds formed during the thermal decomposition of the phosphonates . Straight away, the degradation of the hard segments takes place, followed by degradation of the soft segments, which are the most resistant ones, as reported in the literature . The weight loss of the phosphonated foams in the temperature range 320–440 °C is about 70 wt% whereas for PU F4811 foam an increase of about 80 wt% can be registered.…”

Section: Resultsmentioning

confidence: 66%

Fire retardant functionalized polyol by phosphonate monomer insertion

et al. 2015

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A strategy for synthesis and functionalization of polyurethanes (PUs) is described. Polyols bearing terminal groups were prepared by anionic ring-opening copolymerization between propylene oxide and epoxy dimethylphosphonate (POPh). The direct insertion of POPh improves the flammability of PUs. Therefore the structure, properties and flame retardant properties of polyether polyols and PUs were studied. The structure of the polyether polyols was confirmed by gel permeation chromatography (GPC), nuclear magnetic resonance spectroscopy (NMR) and matrix assisted laser desorption ionization time-of-flight (MALDI-TOF). The thermal stability was determined by TGA (thermogravimetric analysis). The morphological structure was analysed by scanning electron microscope (SEM). The elemental composition of the charred residues was determined by energy dispersive x-ray spectrometer (EDAX). The introduction of POPh presents the advantage of being able to increase the percentage of phosphorus introduced in the polyol, which slightly modifies the thermal stability of the phosphorylated foams. The temperature decreased as the phosphorus was incorporated and the percentage of char increased as well.

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Section: Resultsmentioning

confidence: 66%

Fire retardant functionalized polyol by phosphonate monomer insertion

et al. 2015

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“…The TGA curves have distinct regions of weight loss, implying that different stages of degradation occur in the sample. 19,[33][34][35][36][37][38][39][40] Table 2 compiles characteristic temperatures for the degradation process, T 5 , T 50 and T max that refer to temperatures of 5 and 50% weight loss and of the maximum rate of weight loss of the PUs. PUs are thermally degraded through different basic mechanisms: (a) the urethane bond dissociating into its starting components, that is, alcohol and NCO; (b) breaking of the urethane bond with the formation of primary amine, carbon dioxide and an olefin; (c) splitting the urethane bond into secondary amine and carbon dioxide; and (d) transesterification type bimolecular displacement.…”

Section: Resultsmentioning

confidence: 99%

“…The storage modulus (E 0 ) as a function of temperature plots shows a drop in stiffness for each material, accompanying the soft domain glass transition. 14,16,[39][40][41][42] At low temperatures, the modulus E 0 shows a high and constant value characteristic of its glassy state. The miscibility between hard and soft segments increases the T g (increases the relaxation time of molecular motion) and this in turn raises the temperature of the abrupt modulus drop.…”

Section: Resultsmentioning

confidence: 99%

Enhanced polyurethanes based on different polycarbonatediols

Costa¹,

Nohales²,

Félix

et al. 2012

Journal of Elastomers & Plastics

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Segmented thermoplastic polyurethanes (PUs) were prepared from 4,4 0 -diphenylmethane diisocyanate (MDI), 1,4-butanediol (BD) and different macrodiols with a molar mass of 1000. Properties of those PUs based on polycarbonatediol (PCD) were compared with their homologous based on polyesterdiol and polyetherdiol as macrodiols. The proportion used in this study was macrodiol:BD:MDI ¼ 1:2:3, in mole ratio. The hard segment weight percentage is 48 wt% for different PUs. Thermogravimetric analysis, differential scanning calorimetry, differential mechanical analysis, Fourier transform infrared-attenuated total reflection spectroscopy, as well as mechanical properties and retention on flexural properties tests were employed to characterize the physicochemical, thermal and mechanical properties of different PUs. Comparison of PUs based on PCD, ester and ether macrodiols indicates a better miscibility, higher hard segment-soft segment interactions and durability for the ones based on PCD. It is especially noticeable that the transparency of the films obtained with PCD as macrodiols as well as their good tensile strength and performance to standard durability tests, in comparison with those based on polyester and polyether. This trend could be related with a better miscibility caused by the highest hard segment-soft segment interactions favored by the presence of the carbonate groups.

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“…Miscibility of IPM and the extent of domain separation were determined from the glass transition temperature of the soft segments, identified through DMA analysis. Previous studies have shown that as the molecular weight of the soft segment increases, the T g value of PTMO shifts towards lower temperatures and the maximum becames sharper, without plasticizer [ 34 ]; the T g values obtained from DMA measurements are illustrated in Figure 5 .…”

Section: Resultsmentioning

confidence: 99%

Isopropyl Myristate-Modified Polyether-Urethane Coatings as Protective Barriers for Implantable Medical Devices

et al. 2009

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Polyurethane films have potential applications in medicine, especially for packaging implantable medical devices. Although polyether-urethanes have superior mechanical properties and are biocompatible, achieving water resistance is still a challenge. Polyether based polyurethanes with two different molecular weights (PTMO1000, PTMO2000) were prepared from 4,4’-diphenylmethane diisocyanate and poly(tetra-methylene oxide). Polymer films were introduced using different concentrations (0.5-10 wt %) of isopropyl myristate lipid (IPM) as a non-toxic modifying agent. The physical and mechanical properties of these polymers were characterised using physical and spectroscopy techniques (FTIR, Raman, DSC, DMA, tensile testing). Water contact angle and water uptake of the membranes as a function of IPM concentration was also determined accordingly. The FTIR and Raman data indicate that IPM is dispersed in polyurethane at ≤ 2wt% and thermal analysis confirmed this miscibility to be dependent on soft segment length. Modified polymers showed increased tensile strength and failure strain as well as reduced water uptake by up to 24% at 1-2 wt% IPM.

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Effect of soft segment length on properties of hydrophilic/hydrophobic polyurethanes

Cited by 30 publications

References 30 publications

Fire retardant functionalized polyol by phosphonate monomer insertion

Fire retardant functionalized polyol by phosphonate monomer insertion

Enhanced polyurethanes based on different polycarbonatediols

Isopropyl Myristate-Modified Polyether-Urethane Coatings as Protective Barriers for Implantable Medical Devices

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