New diurethane plasticizers for polyurethane thermoplastics and perspective functional composites

Abstract

A method to synthesize low‐molecular‐mass diurethane compounds via reaction between diisocyanates and various primary and secondary alcohols was presented. A number of diurethanes with the melting points below 100oC were revealed. These diurethanes can be used as fusible plasticizers for thermoplastic polyurethanes (TPU) and for high‐filled composites based thereupon. TPU based on oligotetramethyleneoxide diol and on 4,4′‐diphenylmethane diisocyanate and containing 30% of fusible diurethanes were produced. In the presence of such plasticizers, a 3‐order increase in magnitude of the melt flow index was demonstrated. Data evincing significantly larger strength values of TPU and of tungsten‐containing high‐filled composites (94.2 wt %), comparing with thermoplastics plasticized with low‐molecular‐mass liquids, were presented. The mechanism of this phenomenon attributed to the partial crystallization of diurethanes in TPU compositions was described. Samples of low‐toxic thermoplastic polyurethane having density value of 9.4 g/cm3 and meant for protection of various facilities from radioactive radiation, instead of highly toxic metallic, lead, were prepared. Issues of improving the frost resistance of this new type of TPU were considered. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41481.

Tribological Properties of Self-Lubricating Thermoplastic Polyurethane/Oil-Loaded Microcapsule Composites Based on Melt Processing

“…25 Moreover, a certain amount of the core material (encapsulated lubricating oil) plasticizes the TPU matrix once released, which contributes to the maintainance of ductility. 38 However, when 20 wt % microcapsules are added (TPU-M20), the tensile strength and elongation at break turn to 26.3 MPa and 1001.5%, respectively, which correspond to reductions of 24.2 and 12.3%, respectively, as compared with that of TPU-M0. This might be because when excess microcapsules are loaded, more microcapsules get broken (as observed in the cryogenic surfaces in Figure 1e) during the extrusion process and more encapsulated lube base oil is released, which reduces the compatibility with the TPU matrix, thus deteriorating the mechanical properties of the composites.…”

“…This can be explained that when the TPU composites are subjected to external forces and generates some microcracks inside, the less deformed microcapsules (as shown in Figure ) get deformed or even ruptured to absorb part of the crack propagation energy, meanwhile have some pinning and deflecting effects to prevent further crack expansion. , Besides, the shell material of microcapsules (PUF) is a thermosetting resin, which improves the strength of the matrix due to its own superior strength . Moreover, a certain amount of the core material (encapsulated lubricating oil) plasticizes the TPU matrix once released, which contributes to the maintainance of ductility . However, when 20 wt % microcapsules are added (TPU-M20), the tensile strength and elongation at break turn to 26.3 MPa and 1001.5%, respectively, which correspond to reductions of 24.2 and 12.3%, respectively, as compared with that of TPU-M0.…”

Novel Polyurethane Elastomer Modified by Hybrid Shell Nano-/Microcapsules for Unique Self-Lubricating Behavior

“…35,36 At the same time, liquid paraffin is released from the damaged MCLMs, which affect the tensile strength and elongation at break of the self-lubricating TPU. 37 3.4. Thermal Stability of Self-Lubricating TPU.…”

“…Moreover, with the increase of MCLMs (>1.2 wt %), the tensile strength and elongation at break of self-lubricating TPU began to decrease. This is mainly related to the accumulation of excessive MCLMs in the self-lubricating TPU, which affects the interaction between the MCLMs and the TPU matrix. , At the same time, liquid paraffin is released from the damaged MCLMs, which affect the tensile strength and elongation at break of the self-lubricating TPU …”

The effect of plasticization on the properties of poly(urethaneureas) based on oligoether diols, 2,4-toluenediisocyanate, and aromatic diamines

“…19 Diurethane fusible compounds or mixtures with chemically inert fluids are introduced into thermoplastic materials to reduce the processing temperature. 20 Diurethanes have also been used as chemical resistance stabilizers for polyurethanes. 21 Plasticizing efficiency is characterized using glass transition temperature and elasticity modulus (initial or engineer).…”