Smart Materials - September 2011

This month we're looking at the topic of smart materials.

We've touched on the topic of smart polymers before, from chromogenic and shape memory polymers to conductive plastics, and they remain a promising growth area across a whole variety of industries. You can read more about some of the latest items added to the Polymer Library about smart polymers and how to stay up-to-date in this area below.

However, it's not just polymers that have a lot to offer in the world of smart materials - there are a whole range of other materials with fantastic, unusual properties, ready to be utilised in new and interesting ways. Our sister company Pira are experts on (amongst other things) how these materials are applied in Active and Intelligent Packaging and can help keep you at the forefront of this rapidly developing industry. The 'Active and Intelligent Packaging' e-journal delivers exclusive content and analysis of intelligent packaging and other shelf life-enhancing technologies, as well as reporting on R&D efforts and launches of smart packaging products.

Featured in the latest issue:
Milk delivery - Innovations in packaging are allowing milk producers to target emerging markets
Milk consumption is predicted to surge during the next decade in emerging markets. Driven by heightened demand for convenient and healthier food and drink by the growing middle class, in emerging markets such as Africa and the Middle East, the milk category is also expected to introduce active and intelligent packaging innovations.

For more information visit our site or contact Managing Editor Dan Rogers.

Abstracts

Please see below a selection of abstracts highlighted in the September Newsletter. These are records which relate to various types of smart polymers that have been recently added to the Polymer Library.

Click on the 7-digit accession numbers to find out about ordering a copyright-cleared full text copy of the items shown.

1089864 - LIQUID SENSING: SMART POLYMER/CNT COMPOSITES
The use of carbon nanotube(CNT)-based electrically conductive polymer composites (CPCs) as leakage detectors for organic solvents is discussed. Design concepts and capabilities are outlined and the fundamental of solvent detection are considered, including mechanism, selectivity and electrical response characteristics. The evaluation of a prototype CPC textile based on polylactic acid/multiwalled CNT fibres woven together with glass fibre textiles is described and potential applications in building construction and industrial plants are examined. 43 refs.
Materials Today, 14, No.7-8, July-Aug.2011, p.340-345, ISSN: 1396-7021
Villmow T; Pegel S; John A; Renterberger R; Poetschke P

1089291 - SHAPE RECOVERY IN A THERMOSET SHAPE MEMORY POLYMER AND ITS FABRIC-REINFORCED COMPOSITES (Free Access to Full Text)
A shape memory polymer (SMP) can be deformed from a permanent to a temporary shape above their transformation temperature. Upon reheating, the SMP spontaneously returns to the permanent shape. SMP's show high deformability, but the recovery stresses are very low, thus limiting the size of the components. This paper presents the first results of an ongoing research to develop large sized components based on SMP. To achieve higher recovery stresses, asymmetric fibre reinforced shape memory composites were produced (SMPC) using resin transfer moulding. The results show a 30fold increase in recovery stress, compared to the neat SMP resin. The recovery stress is independent of the deformation temperature, but is strongly affected by the degree of deformation. At higher deformation levels, crazing occurs. Even though the visible effects of the crazing disappear during reheating, it does influence the recovery stress. This indicates that the ability to recover the permanent shape might change in cyclic loading. All composites tested show complete recovery upon reheating. The rate of shape recovery is higher when the fibre reinforcement is loaded in compression. 17 Refs.
Express Polymer Letters, 5, No.3, 2011, p.254-261, ISSN: 1788-618X, DOI: 10.3144/expresspolymlett.2011.25
Ivens J; Urbanus M; De Smet C

1086533 - MECHANOCHROMIC POLYMER BLENDS
Mechanochromic polymer blends, i.e. polymer blends characterised by optical responsiveness to mechanical stimuli, have evoked major interest and experienced significant progress in recent years. Various examples are reported of chromogenic materials composed of a functional dye covalently linked to the polymer chains or physically dispersed in the continuous macromolecular matrix, with the latter appearing to be a more sustainable route for the industrial scale-up of these materials. This feature article examines the properties and performances of various mechanochromic materials prepared by using different thermoplastic polymers with non-covalently incorporated aggregachromic dyes. The aggregachromic dyes include oligo(p-phenylene vinylene) derivatives, stilbene derivatives, poly(phenylene ethynylene) derivatives and perylene derivatives. More specifically, the general mechanism underlying the optical phenomenon is introduced and the different approaches used to obtain chromogenic materials are presented and discussed, considering both dye features and polymer characteristics. The combination of the properties of the blend components can often result in drastic differences in the material chromogenic responsiveness. The article concludes by commenting on and discussing the application of this kind of polymer device as a new type of advanced materials and the perspective thereof. 100 refs.
Journal of Materials Chemistry, 21, No.23, 21st June 2011, p.8282-8291, ISSN: 0959-9428, DOI: 10.1039/c0jm03653f
Pucci A; Ruggeri G

Offers

Don't forget! You can save £100 on the Chromogenic Polymers Bulletin if you purchase together with the Thermochromic Phenomena in Polymers update.