Inspired by biological systems in which damage triggers an autonomic healing response, structural polymers and polymer matrix composites have been recently developed that possess the ability to self-heal. Self-healing is accomplished by incorporating a microencapsulated healing agent and a catalytic chemical trigger within a polymer matrix. When the material is damaged, the microcapsules ruptur...

Mechanical properties of polymer nanocomposites are significantly affected by spatial ordering of nanoparticles (NPs) which can be modified under shear flow fields. Polymer-grafted iron oxide NPs form strings, well-dispersed, and percolated anisotropic nanostructures depending on grafting density, and herein their mechanical properties under large oscillatory shear flows are reported. We show t...

A polymer nanocomposite was produced by ultrasonic-assisted dispersion of multiwalled carbon nanotubes (MWCNTs) in a polycarbonate matrix using p-xylene and dichloromethane as the solvents. The filler loading was varied from 1 to 3 wt % in order to examine the effect of MWCNTs on the structure and properties of the composites. The nanocomposites were characterized by DSC, DTA, TGA, UV-vis, FTIR...

Hydrophilic matrix tablets (matrices) for oral use are designed to hydrate on swallowing, and form a ‘gel’ layer of hydrated polymer at the tablet surface to control the rate of drug release during passage of the matrix through the gastrointestinal tract. During gastrointestinal transit, the matrices are reduced in size through surface erosion and dissolution. This reduces the probability of ex...

Biodegradable polymer scaffolds were prepared from chitosan with varying degree of deacetylation for in vitro culture of human breast cancer MCF-7 cell lines. These polymers were characterized in terms of functional groups by FTIR and swelling properties. Polymers having high degree of deacetylation showed better swelling properties irrespective of the molecular weight. These polymers were bioc...

the objective of this study was to formulate and evaluate the drug-polymer interaction of mefenamic acid (ma) using two polymers with different characteristics as ethylcellulose (ec) and/or cellulose acetate phthalate (cap). microspheres were prepared by the modified emulsion solvent evaporation (mese). the effect of drug-polymer interaction was studied for each of microspheres. important param...

A self-healing approach for optically transparent thermoplastic polymers, based on plasticizer-induced solvent welding, is reported. For the specifi c system investigated, dibutylphthalate (DBP) fi lled urea-formaldehyde capsules are dispersed in a polymethylmethacrylate (PMMA) matrix. Upon a damage event, DBP is released into the crack, and locally plasticizes and swells the polymer, enabling ...

Ionic conductivity involving ion transport in polymer electrolytes has been a major focus of polymer battery research, and an important concept in understanding the mechanisms of ionic transport in polymers is the issue of the coupling between ion motion and the relaxation of the polymer segmental chain. This means that, in typical polymer electrolytes, ion transport is strongly coupled to the ...

Polymer-nanoparticle (NP) interfacial interactions are expected to strongly influence the properties of nanocomposites, but surprisingly, experiments often report small or no changes in the glass transition temperature, Tg. To understand this paradoxical situation, we simulate nanocomposites over a broad range of polymer-NP interaction strengths, ε. When ε is stronger than the polymer-polymer i...