Highly Branched Bio-Based Unsaturated Polyesters by Enzymatic Polymerization.

A one-pot, enzyme-catalyzed bulk polymerization method for direct production of highly branched polyesters has been developed as an alternative to currently used industrial procedures. Bio-based feed components in the form of glycerol, pentaerythritol, azelaic acid, and tall oil fatty acid (TOFA) were polymerized using an immobilized lipase B (CALB) and the potential for an enzymatic synthesis of alkyds was investigated. The developed method enables the use of both glycerol and also pentaerythritol (for the first time) as the alcohol source and was found to be very robust.

The Current State of Silicone-Based Dielectric Elastomer Transducers.

Silicone elastomers are promising materials for dielectric elastomer transducers (DETs) due to their superior properties such as high efficiency, reliability and fast response times. DETs consist of thin elastomer films sandwiched between compliant electrodes, and they constitute an interesting class of transducer due to their inherent lightweight and potentially large strains. For the field to progress towards industrial implementation, a leap in material development is required, specifically targeting longer lifetime and higher energy densities to provide more efficient transduction at lower driving voltages.

Stability of Asp(B28) Insulin Exposed to Modified and Unmodified Polypropylene.

Polypropylene (PP) plates have been modified with two different hydrophilic polymeric materials, poly(N,N-dimethylacrylamide) (poly(DMAAm)) and poly(poly(ethylene glycol)methacrylate) (poly(PEGMA)) in order to reduce insulin adsorption when the plates were exposed to insulin aspart (Asp(B28) insulin). The influence of surface modification on the chemical and physical stability of Asp(B28) insulin was evaluated by two chromatographic methods, size exclusion chromatography (SEC) and reverse phase high pressure liquid chromatography (RP-HPLC) and the Thioflavin T assay. A clear difference in the stability of Asp(B28) insulin was observed between the three tested surfaces.

Adsorption and aqueous lubricating properties of charged and neutral amphiphilic diblock copolymers at a compliant, hydrophobic interface.

We have investigated the adsorption and lubricating properties of neutral and charged amphiphilic diblock copolymers at a hydrophobic polydimethylsiloxane (PDMS) interface in an aqueous environment. The diblock copolymers consist of a hydrophilic block of either neutral poly(ethylene glycol) (PEG) or negatively charged poly(acrylic acid) (PAA) and of a hydrophobic block of polystyrene (PS) or poly(2-methoxyethyl acrylate) (PMEA), thus generating PEG-b-X or PAA-b-X, where X block is either PS or PMEA. The molecular weight ratios were roughly 1:1 with each block ca.

RAFT copolymerization of itaconic anhydride and 2-methoxyethyl acrylate: a multifunctional scaffold for preparation of "clickable" gold nanoparticles.

RAFT copolymerization of 2-methoxyethyl acrylate and itaconic anhydride - a monomer derived from renewable resources - is carried out in a controlled fashion. The copolymer allows preparation of gold nanoparticles with abundant surficial carboxyl and alkyne functional groups that are dendronized via Cu(I)-mediated "click" reaction.