New Stratagem for Designing High‐Performance Thermoplastic Polyurethane by Using a New Chain Extender

Abstract

The high content and regular distribution of hard segment (HS) are necessary to achieve high‐performance thermoplastic polyurethane (TPU), and the HS unit of TPU is generated from the reaction of diisocyanate and chain extender. However, the traditional chain extenders are mainly aliphatic diol that cannot provide rigid groups to improve polyurethane performances. Herein, a novel chain extender bis(hydroxyethyloxycarbonylamino)hexane (BHH) that contains two urethane groups is designed and used to construct high‐performance TPU by increasing content and regular distribution of HS. BHH is synthesized using ethylene carbonate (EC) and hexamethylenediamine (HDA) via a ring‐opening reaction. Subsequently, the effect of BHH on the polyurethane performances is studied with respect to a typical TPU by using polytetramethylene ether glycol (PTMG) and hexamethylene diisocyanate (HDI) as the starting materials. The amount of HDI considerably differs for each polyurethane, aiming to ensure the same total content of urethane groups. When compared with the traditional ethylene glycol‐extended polyurethane, the size and distribution of the HS domains of the BHH‐extended polyurethane are obviously more homogeneous, which proves BHH‐extended polyurethane has better microphase separation. Furthermore, ordered hydrogen bonding, the mechanical properties, and heat‐resistance performance are significantly improved, suggesting a potential method to design TPU delivering outstanding performance.

Polysiloxane-Based Polyurethanes with High Strength and Recyclability

“…The peaks in the carbonyl region from 1610 to 1800 cm −1 could be resolved into two peaks at 1699 and 1726 cm −1 ( Figures S1 and S2 ), corresponding to hydrogen-bonded and free carbonyl groups, respectively [ 53 ]. Hydrogen bonding associations (HBA) are related to the proportion of carbonyl groups and can be calculated using the following formula [ 54 ]: where S 1699 represents the area of the hydrogen-bonded carbonyl peak at 1699 cm −1 and S 1726 represents the area of the free carbonyl peak at 1726 cm −1 .…”

Controllable Design and Preparation of Hydroxyl‐Terminated Solution‐Polymerized Styrene Butadiene for Polyurethane Elastomers with High‐Damping Properties

“…The area with high modulus corresponding to HS is shown as a bright area, and that with a low modulus corresponding to SS is shown as a dark area. [43,44] The prepared HTSSBR-PUs exhibited a clear phase separation and incompatibility between SS and HS due to the high HS content.…”

“…From a thermodynamic perspective, HS contains a polar urethane group, while SS has a weak polarity, leading to the incompatibility between them. [44] Hydrogen bond only forms among HS, which promotes microphase separation because of the absence of proton donors and acceptors in SS. From a kinetic perspective, the MDI, BDO, and TMP in HS result in a high degree of symmetry and regularity, which promotes microphase separation.…”

Unprecedented Strength Polysiloxane-Based Polyurethane for 3D Printing and Shape Memory

“…Particularly, the reaction is difficult to control and usually requires low temperature. ,, Amine can react with cyclic carbonate to form a substance with a carbamate bond . This substance has all the advantages of traditional polyurethane materials and is also environmentally friendly, so it has attracted the attention of many researchers. , If hydroxy-terminated PDMS with two carbamate bonds is introduced into Si-TPU as a soft segment, it can increase the regularity of the hard segment (HS) and the degree of phase separation, thus improving the mechanical properties of pure Si-TPU.…”

“…28 This substance has all the advantages of traditional polyurethane materials and is also environmentally friendly, so it has attracted the attention of many researchers. 29,30 If hydroxy-terminated PDMS with two carbamate bonds is introduced into Si-TPU as a soft segment, it can increase the regularity of the hard segment (HS) and the degree of phase separation, thus improving the mechanical properties of pure Si-TPU. In this work, for further improvement of the strength of silicone materials, a series of Si-TPUs were synthesized by reacting hydroxyl-terminated PDMS with carbamate bonds (HO−PDMS−OH), isophorone diisocyanate (IPDI), and chain extender 1,4-butanediol (BDO).…”