To
explore the mechanism of how the nanorod surface properties
regulate the compatibilization behavior and the morphology transition
in demixing polymer blends, we perform dissipative particle dynamics
simulations and study the impact of three typical nanorods on the
phase separation kinetics and structure as well as their location
and arrangement under both shear-free and shear conditions with the
variation of nanorod–polymer affinity parameters. Depending
on the dispersion and location of nanorods, blends in the quiescent
case either undergo full phase separation and generate bulky two-phase
morphology, or experience microphase separation and form BμE-like
structure, or proceed viscoelastic phase separation and take the kinetically
trapped cocontinuous network morphology, whereas shear flow can either
accelerate domain coarsening or strongly impact the phase behavior
through shear-induced bulk phase separation or shear-induced ordering
transition. Particularly, the shear-induced lamellar phase in Janus
nanorod-filled blends chooses parallel orientation and displays the
lateral ordering within layers.
In order to reduce the melt temperature (T m ) of the thermotropic crystalline polyarylate and improve its compatibility with poly(ether ether ketone) (PEEK), a series of poly(ether ketone)arylates (PEKARs) containing aryl ether ketone units (AEK) are synthesized through melt transesterification reaction from p-acetoxybenzoic acid, 1,3-bis(4 0 -carboxylphenoxy)benzene and 4,4 0 -bis(pacetoxyphenoxy)benzophenone. The inherent viscosities of these polymers are in the range 0.35-0.81 dL/g. The morphologies and properties of PEKARs are characterized by polarized optical microscopy, wide-angle X-ray diffraction, differential scanning calorimetry, thermal gravimetric analysis, etc. The results show that all PEKARs are semi-crystalline polymers, and the introduction of AEK units can reduce the symmetry of the main chains, leading to decreasing the crystallizability and changing the crystalline form. The PEKARs with AEK less than 30% can exhibit thermotropic liquid crystalline state. The initial and the maximum decomposition temperatures increase with the increase in AEK content. These PEKARs are expected to act as processing agents for PEEK to reduce its processing viscosity.
In this article, sulfonated calixarene was used to modify Mg‐Al hydrotalcite (Mg‐Al‐LDH) prepared by coprecipitation method to improve the interfacial compatibility between nano‐hydrotalcite and waterborne polyurethane (WPU) matrix. Waterborne polyurethane hydrotalcite nanocomposite emulsion (STCR‐LDH/WPU) was prepared by adding modified hydrotalcite into WPU. The tensile strength, surface static contact angle, water permeability rate, and water absorption of the film were measured. FTIR and X‐ray diffraction were used to determine the film‐forming properties. The results showed that the tensile strength increased to 57 MPa, the elongation at break reached 292%, and its water vapor permeability and UV resistance were significantly improved by introducing sulfonated calixarene to modify the hydrotalcite nanosheet structure based on WPU. The compound emulsion gives the coated leather excellent physical and mechanical properties, and the laminated leather has stronger coating abrasion resistance.
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