Synthesis and properties of new liquid crystalline polyurethanes containing mesogenic side chain

Bagheri, Massoumeh; Pourmoazzen, Zhaleh

doi:10.1016/j.reactfunctpolym.2007.10.032

Cited by 28 publications

(9 citation statements)

References 26 publications

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“…The general route for the preparation of LCPUE was outlined in Scheme 2, yield and viscosity of LCPUE were listed in Table 1 and the data showed that the range of the viscosities and yields obtained were 10,744 to 40 692 cP and 76-87 %, respectively. Range of the viscosities obtained also provides the information of the molecular weight of each polymer synthesized where high value of viscosity indicates high molecular weight of the polymer produced and vice versa (Bagheri & Pourmoazzen, 2008). In this case, all LCPUE samples displayed fairly high molecular weight in accordance with the results demonstrated.…”

Section: Polymer Synthesissupporting

confidence: 77%

New Liquid Crystalline Polyurethane Elastomers Containing Thiazolo [5,4d] Thiazole Moiety: Synthesis and Properties

Issam¹,

Rashidah²

2012

Polyurethane

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Section: Polymer Synthesissupporting

confidence: 77%

New Liquid Crystalline Polyurethane Elastomers Containing Thiazolo [5,4d] Thiazole Moiety: Synthesis and Properties

Issam¹,

Rashidah²

2012

Polyurethane

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“…The values of molecular weight and intrinsic viscosity for our PU samples are in accordance with Ž agar's similar research result for noncarboxylated, carboxylated Pus, and PU-ionomers 35 and Bagheri's liquid crystalline Pus. 36 The viscosity-average molecular weights of the synthesized PU samples (BDO-extended PU and silk-inspired PU) ranged from 13,000 to 15,000 thus being not comparable to those of commercial biomedical polyurethanes (e.g., Dow BPU). but they all still can be electrospun to form fibrous membranes.…”

Section: Molecular Weights Of the Pu Samplesmentioning

confidence: 93%

Silk‐inspired polyurethane containing GlyAlaGlyAla tetrapeptide. II. physical properties and structure

Liu

Zhou

Liu

et al. 2013

J of Applied Polymer Sci

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Biomedical polyurethane (BPU) and silk fibroin have similarly molecular architecture in their primary and aggregate structure, both of which have amide bonds and microphase separation, and they have been employed as scaffold materials for biomedical applications. Based on this, as the featured peptide sequence of silkworm silk fibroin, GlycineAlanineGlycineAlanine (GlyAlaGlyAla) tetrapeptide was synthesized by using traditional liquid-phase peptide synthesis method with Boc-protected glycine and alanine as starting materials, and was transformed to its derivative with two amine-terminated functional groups. The derivative was introduced as a chain extender into the backbone to form the hard segment of a silk-inspired PU with urea-linkage. Related measurements show that molecular weight of the synthesized silk-inspired PU ranged from 13,000 to 15,000. Fourier transform infrared (FTIR) absorption bands of Amides I and II are at 1651 cm À1 and 1534 cm À1 , and Raman absorption band of Amide III is at 1302 cm À1 . UV-Vis absorption peak of the silk-inspired PU is at 266 nm. This new concept and strategy may allow the fabrication of a new class of thermoplastic polyurethane elastomers to mimic the structure and properties of silk fibroin of silkworms and spiders. Information provided by this study may be used to better understand the correlation between the natural and man-made materials.

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“…A pHsensitive halochromic PU was investigated in our laboratory because PU was a versatile polymer that could be applied to various industrial fields (coating, textile, automotive, and construction) owing to its excellent properties such as flexibility, shape recovery, insulation capability, and easy modification [13,14]. The PU surface can be modified to improve the hydrophilicity and biocompatibility [19][20][21], to provide crystallinity [22], to increase the photosensitivity [23], and to reduce the surface resistance of PU [24]. Previously, thermo-or photosensitive polymers showing colour change to display the changes in the surrounding were applied to smart fabrics [15,16].…”

Section: Introductionmentioning

confidence: 99%

Water‐compatible, pH‐sensitive, colour‐changing polyurethane with low‐temperature flexibility

Chung

Jung

Chun

2017

Coloration Technology

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A pH indicator (Bromocresol Green, Bromocresol Purple, or Thymol Blue) is grafted onto polyurethane (PU) using 2,2-dimethylolpropanoic acid (DMPA) to enhance water compatibility. The indicator-grafted, watercompatible PU is analysed for soft-segment thermal, tensile, and shape recovery properties, fast colour change depending on various pH conditions, and low-temperature flexibility. The PU surface becomes water compatible as DMPA content increases, and the characteristic UV-vis absorbance is observed for each grafted indicator. The PU series exhibits a sharp increase in tensile stress and crosslink density at low DMPA content, but a decrease with increased DMPA content. The glass transition temperature increases significantly with increased DMPA content. Shape recovery remains high, but shape retention sharply decreases after an indicator is grafted. The grafting of pH indicator onto PU improves the low-temperature flexibility and imparts an immediate colour change according to the solution pH and grafted indicator.

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Synthesis and properties of new liquid crystalline polyurethanes containing mesogenic side chain

Cited by 28 publications

References 26 publications

New Liquid Crystalline Polyurethane Elastomers Containing Thiazolo [5,4d] Thiazole Moiety: Synthesis and Properties

New Liquid Crystalline Polyurethane Elastomers Containing Thiazolo [5,4d] Thiazole Moiety: Synthesis and Properties

Silk‐inspired polyurethane containing GlyAlaGlyAla tetrapeptide. II. physical properties and structure

Water‐compatible, pH‐sensitive, colour‐changing polyurethane with low‐temperature flexibility

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