Blending In Situ Polyurethane-Urea with Different Kinds of Rubber: Performance and Compatibility Aspects

Abstract

Specific physical and reactive compatibilization strategies are applied to enhance the interfacial adhesion and mechanical properties of heterogeneous polymer blends. Another pertinent challenge is the need of energy-intensive blending methods to blend high-tech polymers such as the blending of a pre-made hard polyurethane (-urea) with rubbers. We developed and investigated a reactive blending method to prepare the outstanding blends based on polyurethane-urea and rubbers at a low blending temperature and without any interfacial compatibilizing agent. In this study, the polyurethane-urea (PUU) was synthesized via the methylene diphenyl diisocyanate end-capped prepolymer and m-phenylene diamine based precursor route during blending at 100 °C with polar (carboxylated nitrile rubber (XNBR) and chloroprene rubber (CR)) and non-polar (natural rubber (NR), styrene butadiene rubber (sSBR), and ethylene propylene butadiene rubber (EPDM)) rubbers. We found that the in situ PUU reinforces the tensile response at low strain region and the dynamic-mechanical response up to 150 °C in the case of all used rubbers. Scanning electron microscopy reveals a stronger rubber/PUU interface, which promotes an effective stress transfer between the blend phases. Furthermore, energy filtered transmission electron microscopy (EFTEM) based elemental carbon map identifies an interphase region along the interface between the nitrile rubber and in situ PUU phases of this exemplary blend type.

Synthesis and Characterization of New Polycarbonate-Based Poly(thiourethane-urethane)s

“…[ 5 ]. The PUs can also form suitable blends [ 14 , 15 , 16 , 17 , 18 ] or composites [ 19 , 20 , 21 , 22 , 23 ].…”

Improved covulcanization and dynamic properties of millable polyurethane elastomer/natural rubber blends: Thermal pretreatment

“…Natural rubber (NR) possesses a unique combination of toughness, flexibility, mechanical and dynamic properties together with a relatively low cost 14 . The blends of NR with different varieties of PU are quite interesting, as demonstrated in previous reports 15 . It was reported that NR/MPU blends crosslinked with sulfur vulcanization system had better mechanical properties than the corresponding TPU/NR blends 16 .…”

“…14 The blends of NR with different varieties of PU are quite interesting, as demonstrated in previous reports. 15 It was reported that NR/MPU blends crosslinked with sulfur vulcanization system had better mechanical properties than the corresponding TPU/NR blends. 16 The microstructures of MPU/NR blends were analyzed by positron annihilation lifetime spectroscopy, and the relative free volume of the blend exhibited a positive variation from the linear additivity relation, confirming the immiscibility features between the two components as expected.…”

Mini-Review of Self-Healing Mechanism and Formulation Optimization of Polyurea Coating

“…As such, the sample can be broken and healed via repeated hydrogen bonding. Comparing monodentate and bidentate urea hydrogen bonds, bidentate hydrogen bonds are capable of forming stronger hydrogen linkages [ 56 ] and hence dissociate close to the polymer decomposition temperature [ 57 ]. Dynamic Covalent …”