Preparation and properties of polyester nanocomposites: Effects of mixing

Abstract

A multistep mixing technique to manufacture highly intercalated/exfoliated nanocomposites of layered silicates in thermosetting resins was developed and successfully tested up to 9% nanoparticle content. We investigated the influences of mixing conditions on linear and nonlinear viscoelastic properties of processed clays and polyester suspensions. The effects of shear and mechanical mixing on the state of dispersion and microstructure of the cured nanocomposites were examined by the XRD and TEM techniques. Transient viscosities and linear viscoelastic data for the nanocomposites demonstrated significant enhancement by increasing speed and time of mechanical mixing. The solid state characterization techniques confirm mixed to highly exfoliated and delaminated microstructures were attained by the proposed method. Our observations indicate that the multistage mechanical mixing following a stationary step can be used to produce thermosetting and thermoplastic nanoparticles with the improved properties. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers

Unsaturated Polyesters and Vinyl Esters

“…The print-through effect often observed with vacuum-assisted resin injection processes to produce, for example, boats hulls and similar objects, was also reduced by compounding the UPR with an organo-montmorillonite nanoclay [80]. The modification of the flow-behavior of UPRs by nanoclays is complex and has been studied in detail [81,82].…”

Application of rheology as a tool to estimate the mixing quality of elastomeric nanocomposites and comparing with small-angle X-ray scattering microstructural study

“…18 Mixing method, 19 mixing capacity, 20 mixing energy, 21 the order of mixing of raw materials, 22 extruder screw type in melt mixing, 23 and type and shape of blades in solution mixing [24][25][26][27] have a direct effect on the dispersion and distribution of nanoparticles. The capacity of mixing depends on the properties of pure polymeric materials such as surface tension and rheological properties, [28][29][30] particle properties such as structure, cohesion, shape, size and particle size distribution, 25,29,31,32 process conditions such as shear rate, temperature and mixing time, 28,[33][34][35][36] and the formulations of materials such as interfacial tension of filler and matrix, additives, coupling agents, particle surface modification operations and relative amount of used materials. 20,[37][38][39][40] In fact, increasing the rate of dispersion and distribution of nanoparticles in the polymer substrate increases the available surface area of nanoparticles and the amount of polymer chains whose motion is slowed down by nanoparticles.…”

Percolation network formation in poly(4-vinylpyridine)/aluminum nitride nanocomposites: Rheological, dielectric, and thermal investigations

“…To incorporate nanofillers in polymer matrices, several methods have been reported, namely solution processing , melt mixing compounding , mechanical stretching , curing/in situ polymerization , the use of latex technology or magnetic fields , and coagulation method . Most reported studies are focused on carbon‐based nanofillers , metal oxides , and less on aluminum nitride (AlN).…”