Diaminobisbenzothiazole chain extended polyurethanes as a novel class of thermoplastic polyurethane elastomers with improved thermal stability and electrical insulation properties

Abstract

This work was devoted to the development of a new class of modified polyurethane as an electrical insulating material. For this purpose, NCO‐terminated urethane prepolymers at different NCO contents were prepared and chain extended by 6,6′‐oxybis(2‐aminobenzothiazole) (ABT) to produce thermoplastic polyurethane elastomers. All of the polymers were characterized by FTIR and 1HNMR spectroscopies and examined for their thermal, mechanical, and electrical properties. The dynamic mechanical measurements results showed two glass transitions indicating phase separation. A considerable improvement in the thermal and electrical properties in comparison to common polyurethanes was detected for these polymers. The level of enhancement in the measured properties was related to the polyol molecular weight, hard segment content, and consequently the amount of the introduced urea and benzothiazole moieties. These findings indicated the improved high service temperature performance of these materials as electrical insulator for metallic surfaces. Copyright © 2008 John Wiley & Sons, Ltd.

Thermoplastic polyurethanes derived from petrochemical or renewable resources: A comprehensive review

“…At a temperature of about 4008C, the decomposition of the ester groups (presented in the structure of the polyol) and aromatic groups (introduced by the chain extender) occurs. This confirms earlier findings that the values of T d10% and T dmax increasing when the polyol molecular weight increasing [40].…”

“…⁠In the case of PUs, the main aim is to produce bio‐polyol or bio‐isocyanate. For the synthesis of polyols chemically modified plant oils for example linseed oil , sunflower oil , palm oil , cotton oil , soybean oil , tung oil , castrol oil ⁠ hempseed oil ,⁠ corn oil , canola oil are used. Plant oils are mixtures composed of esters of glycerin, saturated acids (e.g., stearic and palmitic acid) and unsaturated fatty acids (e.g., linolenic, linoleic, oleic acid).…”

“…Thermoplastic polyurethanes obtained by prepolymer method using PCL, MDI, and BDO[72]. Mechanical and thermal properties of TPUs obtained using TDI, ABT, and PCL-based polyols with different molecular weights[40].…”

Preparation and properties of compatible starch-polycaprolactone composites: Effects of hard segments in the polyurethane compatibilizer

“…Also, from Fig. c and d, the peaks at 7.15–7.44 ppm of the 1 H‐NMR curve for MDIPU and TDIPU were ascribed to the benzene aromatic characteristic absorption peaks while, the weak peaks at 8.71–8.85 ppm corresponded to the carbamate characteristic absorption peaks of the NH in the urethane group . The results implied that the use of aromatic MDI or TDI as the hard segment and PCL diol as the soft segment in the preparation of PCLPU compatibilizer also generated urethane bonds in the process and thus, the reaction proved to be successful.…”

“…Also, from Fig. 1c and d, the peaks at 7.15-7.44 ppm of the 1 H-NMR curve for MDIPU and TDIPU were ascribed to the benzene aromatic characteristic absorption peaks while, the weak peaks at 8.71-8.85 ppm corresponded to the carbamate characteristic absorption peaks of the NH in the urethane group [48]. The results…”