Tuning the properties of segmented polyurea by regulating soft-segment length

2018 ◽  
Vol 135 (21) ◽  
pp. 46284 ◽  
Author(s):  
Nahid Iqbal ◽  
Manorama Tripathi ◽  
Surekha Parthasarathy ◽  
Devendra Kumar ◽  
Prasun Kumar Roy
Keyword(s):  
Soft Segment ◽  
Segment Length

Influence of the soft segment length on the properties of water-cured poly(carbonate-urethane-urea)s

2014 ◽  
Vol 26 (1) ◽  
pp. 57-67 ◽  
Author(s):  
Magdalena M. Mazurek ◽  
Karolina Tomczyk ◽  
Monika Auguścik ◽  
Joanna Ryszkowska ◽  
Gabriel Rokicki
Keyword(s):  
Soft Segment ◽  
Segment Length ◽  
Poly Carbonate

scholarly journals Study of waterborne polyurethane materials under aging treatments. Effect of the soft segment length

2020 ◽  
Vol 138 ◽  
pp. 105357 ◽  
Author(s):  
Anny C. Ospina ◽  
Víctor H. Orozco ◽  
Luis F. Giraldo ◽  
Mónica Fuensanta ◽  
José Miguel Martín-Martínez ◽  
...  
Keyword(s):  
Soft Segment ◽  
Waterborne Polyurethane ◽  
Segment Length

Crystallinity and morphology of segmented polyurethanes with different soft-segment length

1996 ◽  
Vol 62 (4) ◽  
pp. 631-638 ◽  
Author(s):  
Fengkui Li ◽  
Jianan Hou ◽  
Wei Zhu ◽  
Xian Zhang ◽  
Mao Xu ◽  
...  
Keyword(s):  
Soft Segment ◽  
Segment Length ◽  
Segmented Polyurethanes

Effect of the average soft-segment length on the morphology and properties of segmented polyurethane nanocomposites

2006 ◽  
Vol 102 (1) ◽  
pp. 128-139 ◽  
Author(s):  
Bradley Finnigan ◽  
Peter Halley ◽  
Kevin Jack ◽  
Alasdair McDowell ◽  
Rowan Truss ◽  
...  
Keyword(s):  
Soft Segment ◽  
Segment Length ◽  
Segmented Polyurethane ◽  
Polyurethane Nanocomposites

scholarly journals Preparation of Associative Polyurethane Thickener and Its Thickening Mechanism Research

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Gao Nan ◽  
Zhang Zhuo ◽  
Dong Qingzhi
Keyword(s):  
Molecular Weight ◽  
Particle Size ◽  
Soft Segment ◽  
Synthesis Process ◽  
Segment Length ◽  
Solvent Ratio ◽  
Aqueous Dispersions ◽  
Before And After ◽  
Size And Morphology ◽  
End Capping

Associative polyurethane (PU) thickener has been synthesized by preparing the prepolymer with the reaction of polyethylene glycol (PEG) and isophorone diisocyanate (IPDI), which then end-capping with long-chain alkanol. The synthesis process, as well as hydrophilic chain length, theoretical molecular weight, solvent ratio, and thickener percentages, has been researched. The results shows that it reaches the upmost thickening effect when the theoretical molecular weight is under 20000, soft-segment length is under 4000, solvent ratio is 1 : 1, and thickener percentages are controlled at 10%. Furthermore, thickening mechanism of PU thickener has been analyzed detailedly through the measurement of the critical micelle concentration (CMC) of PU thickener and analysis of the influence of PU thickener on the particle size and morphology of PU dispersions. It has been observed from the scanning electron microscopy (SEM) that the PU aqueous dispersions produce a certain degree of flocculation when the PU thickener was added, and this flocculation structure has been proved to be a thixotropic structure through the characterization of the change of particle size before and after the thickener is introduced into the PU aqueous dispersions. The CMC measurement results present that the thickening effect will be apparent when the concentration is controlled in a low range.

Effect of soft segment length on the properties of polyurethane anionomer dispersion

Polymer ◽  
1994 ◽  
Vol 35 (5) ◽  
pp. 1095-1099 ◽  
Author(s):  
Young Min Lee ◽  
Jong Cheol Lee ◽  
Byung Kyu Kim
Keyword(s):  
Soft Segment ◽  
Segment Length

Study of the Effect of Soft-Segment Length and Concentration on Properties of Polyetherurethanes. I. The Effect on Physical and Morphological Properties

1985 ◽  
Vol 58 (4) ◽  
pp. 685-700 ◽  
Author(s):  
Zoran S. Petrović ◽  
Jaroslava Budinski-Simendić
Keyword(s):  
Phase Inversion ◽  
Hard Segment ◽  
Soft Segment ◽  
Degree Of Polymerization ◽  
Morphological Properties ◽  
Segment Length ◽  
Hard Phase ◽  
Soft Phase ◽  
Soft Segments ◽  
Two Phases

Abstract 1. Densities of elastomers with crystallizing soft segments were higher than that of the noncrystallizing ones. However, the effect of the soft segment length is not regular and may reflect some specific interactions between two phases as well as instantaneous morphology. 2. Phase inversion as judged by drop of hardness takes place at about ssc=60° or more; a shift to higher ssc gives a greater segment length. 3. Tg of the soft segment in samples with well separated phases is independent of ssc, e.g., the presence of hard phase does not change mobility of the soft phase in samples with ssc=50° or more, in all series. However, Tg is strongly dependent on the soft-segment length. Tg for the soft segment of Mn=650 was −43°C, for Mn=1000 was −62°C, and for Mn=2000, Tg was −75°C. The effect of the presence of the hard phase on mobility of the soft phase seems to vanish for M>2500. 4. Tg of the hard segment at 77°C was clearly observed only in quenched samples with a high hard-segment concentration (80%) and at 93°C in a pure hard segment. 5. Melting of both phases were observed in polymers with long soft segments (Mn=2000). Soft segments of Mn=650 and 1000 do not crystallize. The hard phase crystallizes if its Mn is about 1000 or more or if the degree of polymerization of the hard segment is 3 or above, although exceptions were found in the A series. 6. Spherulitic structures were observed in polymers with low ssc (20% and 40%) polymers and in one with ssc=80°. Thus, both hard and soft phases can form spherulitic structures.

Study of the Effect of Soft-Segment Length and Concentration on Properties of Polyetherurethanes. II. The Effect on Mechanical Properties

1985 ◽  
Vol 58 (4) ◽  
pp. 701-712 ◽  
Author(s):  
Zoran S. Petrović ◽  
Jaroslava Budinski-Simendić
Keyword(s):  
Mechanical Properties ◽  
Chain Length ◽  
Plastic Flow ◽  
Soft Segment ◽  
Maximum Strength ◽  
Segment Length ◽  
Elongation At Break ◽  
Mechanical Methods ◽  
Soft Segments ◽  
Segmented Polyurethanes

Abstract Three series of segmented polyurethanes with different soft segment lengths and concentrations were examined by TMA, DMA, and mechanical methods. Maximum tensile strengths were obtained when ssc was 40–50%, which was explained by a specific interlocking morphology. No significant effect of soft-segment chain length on maximum strength was found, but higher values were found in the C series when ssc was 60%. Elongation at break increases linearly with ssc but indications that shorter soft segments produce higher extensions was attributed to plastic flow. TMA showed that Tg was independent of ssc in the C and, to a degree, in the B series, while temperature of α-transition in DMA was independent of ssc only in the C series at ssc above 50%.

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