Studies on dry‐jet‐wet spun polyurethane fibers. II. Effect of polyurethane shore hardness on spinnability and fiber properties

Abstract

This article reports a study on the spinnability of three different ester type thermoplastic polyurethanes (TPUs) with shore hardness 75A, 85A, 92A using the dry-jet-wet spinning method. The three grades have been analyzed by FTIR, GPC, and 1 H-NMR to establish the difference among them. FTIR indicated that all the three grades were chemically similar and GPC suggests that molecular weight increased with increase in shore hardness. Compositional analysis indicates that the hard segment content increases with increase in shore hardness. Shear viscosity of TPU dope solution increases with increase in shore hardness. Of the three different grades of TPUs studied, only the grades with shore hardness of 85A and 92A are spinnable under the experimental conditions. The fiber properties of three different grades have been compared. Fibers spun with the shore hardness of 85A have good elastomeric properties compared with the other two grades. Lab spun fibers have also been compared with the commercial spandex fibers. V C 2009 Wiley Periodicals, Inc. J Appl Polym Sci 116: 843-851, 2010

Single-Step Synthesis and Characterization of Non-Linear Tough and Strong Segmented Polyurethane Elastomer Consisting of Very Short Hard and Soft Segments and Hierarchical Side-Reacted Networks and Single-Step Synthesis of Hierarchical Hyper-Branched Polyurethane

“…As observed in Scheme 1, the very short, hard segment consists of only two urethane groups in the polymer repeating unit, separated by the hexamethylene group of the original HDI. The soft segment of the polymer, i.e., PEG200, is very short when compared to industrial polyurethanes such as the well-known Lycra ® , in which the soft segment consists of polytetramethylene glycol (PTMG) 2000 and the hard segment consists of two urethane groups and two urea groups in the polymer repeating unit [20][21][22][23][24][25].…”

“…Although the reaction between a diol-terminated soft segment and a diisocyanate is sufficient for the formation of a polyurethane polymer [1,2], the above-described macro-diisocyanate and chain extension synthesis pathway is usually performed with the purpose of obtaining a longer hard segment, thus obtaining significantly strong elastomers, especially when using relatively long and soft segments [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. A well-known example of this is Lycra ® , which is a poly(ether urethane urea) segmented elastomer mostly applied as a textile fiber and also in some biomedical uses [20][21][22][23][24][25].…”

Effect of nanoclay dispersion on liquid–liquid phase separation in a ternary system of segmented polyurethane/dimethylformamide/water system

“…Our earlier study on the effect of shore hardness of TPU of the three grades (GP75AE, GP85AE and GP92AE) on spinnability and fibre properties is reported in our published paper 24. The dry jet‐wet spinnability performance of all the three grades was tested under the optimized spinning parameter obtained for GP85AE 33. Spinnability of all the three grades was compared under the optimized spinning conditions.…”

“…5. The range of temperature selected was deliberately narrow and precisely same as those used during the optimization of spinning parameters for wet spinning of TPU fibres in our previous study 33. In all the cases, the homogeneous phase was observed to enlarge albeit small in value.…”

“…The composition of MDI and polyol content was determined from completely assigned 1 H NMR spectra that have been reported elsewhere 24. The intensity of protons in MDI and dihydric alcohols, i.e.…”