Polyesters characterization

LACCC System. The first dimension in the 2D polyester characterization consisted of a Jasco 880PU pump delivering the acetone-hexane (50.5% 49.5%) solvent mixture, which are the critical conditions for the separation of the polyester samples using one 7-jiim Si-120 silica column (Tessek, Prague, Czechoslovakia) for the LACCC separation. A Erma 7511 refractive index (RI) detector was used to monitor the concentration trace of the fractions. 

Typical polyesters characterized by GPC include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polycylohexylenedimethyl-ene terephthalate (PCT). Polyphthalamides (PPA) and polyamides are also commonly analyzed. 

Poly(lactic acid) (PLA) is a thermoplastic polyester characterized by mechanical and optical properties similar to polystyrene (PS) and polyethylene terephthalate (PET). It is obtained from natural sources, completely biodegradable and compostable in controlled conditions as already stated in previous chapters. PLA offers some key points with respect to classic synthetic polymers, since it is a bioresource and renewable, while raw materials are cheap and abundant compared to oil. From a commercial point of view, a non-secondaiy approach, it can embellish with the word green so fashioned for the major stream consumers. Legislation can also help the commercial diffusion of biopolymers. As an example, a decisive leap has been made with the control of non-biodegradable shopping bags distribution in the European Commission and many of its member states. In addition, PLA has received some interest from the industrial sectors because of its relatively low price and commercial availability compared with other bioplastics. This is the veiy key point for any successful polymer application. In fact, the current price of commercial PLA falls between 1.5 and 2 kg , which is sufficiently close to other polymers like polyolefins, polyesters or poly(vinyl chloride) (PVC). Clearly, the PLA market is still in its infancy, but it is expected that the decrease in the production costs and the improvement in product performance will result in a clear acceleration in the industrial interest for PLA uses. It is estimated that PLA consumption should reach... 

PLA is thermoplastic polyester characterized by good mechanical, thermal and optical properties (see Table 13.1). Neat PLA is generally characterized by good mechanical properties, depending on the grade and stereochemistry, as indicated in Chapters 1 and 2 of this volume, with elastic... 

Ruddick, C.L., Hodge, P., Zhuo, Y. et al. (1999) Cyclo-depolymerization of polyundecanoate and related polyesters characterization of cyclic oligoundecanoates and related cyclic oUgoesters. Journal of Materials Chemistry, 9,2399-2405. 

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