Influence of soft segment structure, hydrogen bonding, and diisocyanate symmetry on morphology and properties of segmented thermoplastic polyurethanes and polyureas.

A comprehensive review of the structure-morphology-property relations in segmented thermoplastic polyurethanes and polyureas (TPU) is provided. Special emphasis is given to the influence of the soft segment structure, polarity, and molecular weight, diisocyanate symmetry and the nature, extent, and strength of hydrogen bonding on the morphology and thermal and mechanical properties of TPUs. Experimental results obtained on composition-dependent TPU morphology and properties by various techniques were also compared by the morphology profiles generated by computational methods such as quantum mechanical calculations and molecular dynamics simulations.

Miniaturized wireless sensor enables real-time monitoring of food spoilage.

Food spoilage results in food waste and food-borne diseases. Yet, standard laboratory tests to determine spoilage (mainly volatile biogenic amines) are not performed regularly by supply chain personnel or end customers. Here we developed a poly(styrene-co-maleic anhydride)-based, miniature (2 × 2 cm) sensor for on-demand spoilage analysis via mobile phones.

3D Printed Biodegradable Polyurethaneurea Elastomer Recapitulates Skeletal Muscle Structure and Function.

Effective skeletal muscle tissue engineering relies on control over the scaffold architecture for providing muscle cells with the required directionality, together with a mechanical property match with the surrounding tissue. Although recent advances in 3D printing fulfill the first requirement, the available synthetic polymers either are too rigid or show unfavorable surface and degradation profiles for the latter. In addition, natural polymers that are generally used as hydrogels lack the required mechanical stability to withstand the forces exerted during muscle contraction.

Effect of reaction solvent on hydroxyapatite synthesis in sol-gel process.

Synthesis of hydroxyapatite (HA) through sol-gel process in different solvent systems is reported. Calcium nitrate tetrahydrate (CNTH) and diammonium hydrogen phosphate (DAHP) were used as calcium and phosphorus precursors, respectively. Three different synthesis reactions were carried out by changing the solvent media, while keeping all other process parameters constant.

Intercalated chitosan/hydroxyapatite nanocomposites: Promising materials for bone tissue engineering applications.

Preparation and characterization of chitosan/hydroxyapatite (CS/HA) nanocomposites displaying an intercalated structure is reported. Hydroxyapatite was synthesized through sol-gel process. Formic acid was introduced as a new solvent to obtain stable dispersions of nano-sized HA particles in polymer solution.

Two new polymers as candidates for rhinoplasty allografts: an experimental study in a rabbit model.

Objectives: This study was performed to evaluate the biocompatibility and tensile strength of two new polymeric materials--a polyfluoro ether-modified thermoplastic polyurethane urea and a polydimethyl silicone elastomer--in an experimental rabbit model.

Methods: The two polymers were implanted inside separate subperichondrial pockets created over the auricular cartilages of 12 rabbits. A control pocket received no implant.

Tunable wetting of polymer surfaces.

A simple method was developed for the preparation of polymeric materials with controlled surface wettability or tunable surface wetting. The method is applicable to a large number of polymers, thermoplastic or thermoset. With this method, it is possible to prepare polymer surfaces with static water contact angles ranging from 0° (superhydrophilic) to greater than 170° (superhydrophobic).