Hard segment polymer

Sheth JP, Klinedinst DB, Wilkes GL, Yilgor E, Yilgor I. Role of chain symmetry and hydrogen bonding in segmented copolymers with monodisperse hard segments. Polymer 2005 46 7317-7322. 

Yoshino M, Ito K, Kita H et al (2000) Effects of hard-segment polymers on C02/N2 gas-separation properties of polyethylene oxide)-segmented copolymers. J Polym Sci Part B Polym Phys 38(13) 1707-1715... 

Figure 3b. DSC scans of hard-segment polymers, (a) 2,4-TDHBD (b) quenched 2,6-TDI/BD (c) 2,6-TDl/ BD-annealed for 1 hr at 423 K.

Table VI contains the general properties for 50-60% HARD SEGMENT polymers. This table contains polymers which have been developed in the past such as the Polyurethanes in the 55 to 65 Shore D hardness (Fascia materials), as well as Poly(urea-urethanes) which are more recent developments. This hard segment range also covers 65 to 75D intermediate modulus materials which are in reality toughened plastics. The raw materials prices are for comparison purposes.

M. Yoshino, K. Ito, H. Kita, K-1. Okamoto, Effect of hard-segment polymers on CO2/N2 gas separation properties of poly(ethylene oxide)-segmented copolymers, J. Polym. Sci. Part B Polym. Phys., 38, 1707-1715 (2000). 

The consequence of temperature elevation is a drastic decrease of stress level and initial modulus (5 MNm (a), 18 MNm (b), and 24 MNm" (c)). Furthermore, an increase of extension set (65 % (a) and 85 % (b)) and an iiKxease airf constancy, respectively, of stress hysteresis (68% (a) and 80% (b)) have been evaluated for the low and intermediate hard segment polymers (a) and (b) while a decrease of these parameters was observed for polyester urethane (c) (extension set 85%, stress hysteresis 80%) in comparison to the measurements at ambient temperature. Thus, at 348 K extension set and stress hysteresis reach their maximum values already for polyester urethane (b) with intermediate hard segment content... 

Blackwell J, Nagaraj an M, Hoitink T. Structure of polyurethane elastomers effect of chain extender length on the structure of MDI/diol hard segments. Polymer 1982 23(7) 950-6. 

W. Wang, P. Ping, X. Chen, X. Jing, Shape memory effect of poly(L-lactide)- based polyurethanes with different hard segments, Polym. Int. 56 (2007) 840-846. 

Z. Pan, L. Yu, N. Song, L. Zhou, J. Li, M. Ding, H. Tan, Q. Fu, Synthesis and characterization of biodegradable polyurethanes with folate side chains conjngated to hard segments, Polym. Chem. 5 (2014) 2901-2910. 

Phillips, R.A. and S.L. Cooper, Phase separation in crystallizable multiblock poly(ether-ester) copolymers with poly(tetramethylene isophthalate) hard segments. Polymer, 35(19) p. 4146.1994. 

Yang, J. H., Chun, B. C., Chung, Y.-C., Cho, J. H. (2003), Comparison of thermal/ mechanical properties and shape memory effect of polyurethane block-copolymers with planar or bent shape of hard segment. Polymer, 44, 3251-8. 

Takahara, A., Tashita, J.-L, Kajiyama, X, Xakayanagi, M., Macknight, W.J. Microphase separated structure and blood compatibility of segmented poly (urethaneureas) with different diamines in the hard segment. Polymer 26(7), 978-986 (1985)... 

Szymczyk A and Roslaniec Z (1999) Sulfonated poly(ether-block-ester) ionomers with anions in the polyester hard segments, Polym Adv Technol 10 579-587. 

---