PVC Formulation | materials feature Adding value to vinyl
PVC is one of the most commonly used plastics, but its reliance on additives means that constant research is needed to find new compounds to improve its perform- ance.
A number of PVC additives have recently been added
to the market, and many have a distinctly sustainable flavour. At the same time, research is continuing to try and improve the properties of PVC with new types of additive. Researchers in Spain, for example, are investigating
how nanoclay fillers might help to improve the proper- ties of PVC. A team at the Public University of Navarre (UPNA) is looking to control the photostability, thermal resistance and gas permeation of PVC composites, as part of the Vinilclay project. “The main aim is to improve photostability proper- ties,” said Antonio Gil, a lecturer in the Department of Applied Chemistry. “Ultraviolet rays, which are responsible for the accelerated degradation of the polymers, cause discoloration and loss of performance – shortening their useful life. Inserting molecules capable of absorbing light radiation increases the composite’s resistance to UV radiation.” The nanofilled polymer composite materials are
developed through the synthesis and treatment of nanoclays inserted into the matrix of the polymer. The company Compuestos y Granzas – which is acting as the co-ordinator – and the L’Urederra R+D Centre are
www.pipeandprofile.com
Researchers are finding new ways to boost the properties of PVC, with
some of them taking a ‘green’ twist. Lou Reade reports
also involved in the project. The nanoparticles tend to be ionic in nature, and can
be incorporated using methods such as ion-exchange. The photoresistance properties, and the range of absorption in the UV-visible region, can also be altered. This means that each method can be adapted to the two main groups of material synthesis applications: opaque plastic nanocomposites; and coloured products. (For coloured products, the desired colour will determine the type of molecule used.) A second objective is for the nanofillers to act
simultaneously as mechanical and flame-retardant reinforcements. “The flame retardants currently used are based on aluminium or magnesium hydroxides, or on flame- retardant plasticisers,” said Gil. “High loadings are used, which leads to a deterioration in the mechanical properties of the final composite.”
May/June 2012 | PIPE & PROFILE EXTRUSION 27
Huntsman has developed an infrared-
reflecting pigment that helps polymer
products of any colour to
reflect solar energy
s
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42