Soluble poly-3-alkylpyrrole polymers on films and fabrics

Conductive textiles with specific properties can be produced by the chemical polymerisation of a range of 3-alkylpyrroles in the presence of textiles. The morphologies of these coatings are altered from the traditional conductive coatings. Comparison using a SEM reveals substantial differences.

Application of soluble poly (3-alkylpyrrole) polymers on textiles

Soluble conducting poly(3-decanylpyrrole) was directly applied to textiles as a nanoparticle emulsion, using a variety of techniques including hand-brushing, dipping and spray painting. These coatings were compared to those formed by chemical polymerization of 3-decanylpyrrole on the surface of the textile by solution, using vapor and spray polymerization methods. The coating formed using chemical polymerization methods had lower surface resistivity than that formed by direct application of a soluble polymer.

It was observed that applied coatings of poly(3-decanylpyrrole) showed a smoother surface morphology with a more even dispersion compared to those formed by chemical methods.

Conjugated polymers for light-emitting applications

Processable conjugated polymers such as those shown in the Figure are highly desirable for applications in, for example, light emitting devices, especially electrochemical light-emitting cells. Here recent progress in Australia on the synthesis and device applications of such polymers is reviewed and the possibility of tuning the emitted color via an intercalation-induced conformational change of the polymer backbone is examined.

Preliminary investigations into using eugenol to recover erased characters on polymers

In this paper we present our preliminary studies on the efficacy of eugenol for the recovery of erased characters on polymers. We have found that eugenol rapidly recovers erased characters when applied to the surface of polymer substrates. By applying eugenol to the surface to be treated using a cotton bud or paintbrush, we were able to revisualize erased characters from a range of polymers, inclluding acrylonitrile butadiene styrene, acrylic, high-impact polystrene, and polystyrene. Eugenol is safe, nonhazardour, and easily sourced reagent for this purpose.

Small diameter Polyurethane vascular graft reinforced by elastic weft-knitted tubular fabric of polyester / spandex

Small diameter vascular grafts were fabricated from pure Polyurethane (PU) as well as PU reinforced with a tubular weft-knitted fabric. The tensile properties of the reinforced composite vascular grafts were compared with that of the tubular fabric itself and the pure PU vascular grafts. The elasticity and strength of the reinforced vascular grafts were improved compared with the tubular fabric. Strength of the reinforced vascular grafts was 5–10 times of the strength of the pure PU vascular grafts. Expanding the tubular fabric to increase the inner diameter of the reinforced vascular graft reduced the graft’s strength and initial modulus, but the difference was reduced as the PU content was increased. For grafts of the same inner diameter, increasing the PU content increased the thickness and strength of the graft wall, which led to a general increase in the strength and initial modulus of the composite vascular grafts.

The effect of dyes on photo-induced chemiluminescence emission from polymers

Weak photo-induced chemiluminescence (PICL) emission is observed when polymers are exposed to UVA or visible light. The presence of dyes can either increase PICL intensity via Type I photosensitisation which generates polymer free radicals, or reduce it via photo-protection. PICL studies on the eight Blue Wool Standards (BWSs) that are used commercially as lightfastness standards show higher PICL intensity from the least photostable BWSs that use triphenylmethane dyes and lower intensity from more photostable BWSs using UVA and visible wavelengths. The relative PICL intensities do not correlate in a stepwise manner with lightfastness ratings of the BWSs. However dye/polymer combinations that emit high levels of PICL relative to the undyed material are unlikely to have acceptable lightfastness. The xanthene dyes fluorescein and eosin Y are more strongly photosensitising than triphenylmethane dyes on wool and both produce higher PICL emission than undyed wool when irradiated with visible light.

Adhesion of polymers

Most industrially applied polymer resins and composites have low surface free energy and lack polar functional groups on their surface, resulting in inherently poor adhesion properties. A strong research momentum to understand polymer adhesion in the last decade has been motivated by the growing needs of the automotive and aerospace industries for better adhesion of components and surface coatings. This paper reviews the recent research efforts on polymer adhesion with a special focus on adhesion mechanisms. It starts with an introduction to adhesion with explanatory notes on adhesion phenomena. Recent research on the adhesion mechanisms of mechanical coupling, chemical bonding and thermodynamic adhesion is then discussed. The area of adhesion promoters is reviewed with the focus on plasma and chemical treatments, along with direct methods for adhesion measurement. The topics of polymer blends and reactive polymerization are considered and the interactions with adhesion mechanisms are reported. The concluding section provides recommendations regarding future research on the contentious aspects of currently accepted adhesion mechanisms and on strategies for enhancing polymer adhesion strength.

Ion and solvent dynamics in gel electrolytes based on ethylene oxide grafted acrylate polymers

Multinuclear pulsed field gradient NMR measurements and rheological viscosity measurements were performed on three series of polymer gel electrolytes. The gels were based on a lithium salt electrolyte swollen into a copolymer matrix comprising an acrylate backbone and ethylene oxide side chains. In each series the side chains differed in length and number, but the acrylate-to-ethylene oxide ratio was kept constant. It was found that the self-diffusion coefficient of the cations was much lower than that of the anions, and that it decreased rapidly when the side chains got longer. In contrast, the self-diffusion coefficient of the anions was found to be independent of chain length. In the gel electrolytes, the diffusion coefficients of the solvent molecules are relatively constant despite an increased viscosity with increasing length of the side chains. However, in salt-free gels made for comparison, the diffusion coefficients of the solvent molecules decreased with increasing length of the side chains, which is consistent with an increased viscosity.

Use of ionic liquids as electrolytes in electromechanical actuator systems based on inherently conducting polymers

The use of ionic liquids (ILs) as electrolytes for electromechanical actuators based on polypyrroles (PPy's) is described. The composition of the electrolytes has a significant effect on the electrochemical properties of the PPy actuator and subsequently on actuator performance, improving cycle life and strain generated. The actuator performance in ionic liquid electrolytes is significantly better than that in traditional organic and aqueous electrolytes.

Developing fast ion conductors from nanostructured polymers

- Introduction
- Polymer electrolytes
- Composite electrolytes
- Conclusions
- References