Stabilisers for Plastics - October 2011
This month we're looking at the topic of stabilisers in plastics.
Plastics are used in so many ways, from various parts of the buildings we work and live in and the everyday objects we rely on, to the cars and aeroplanes we travel in. However, many people are unaware of the critical role that additives play in these objects functioning as they should. Stabilisers are used in many plastics where the polymer alone would not otherwise survive processing or the conditions that it needs to function in. Stabilisers make it possible for us to use affordable plastics in a whole variety of ways and, as such, have played a very real part in increasing our standard of living.
If you have an interest in this area and want to keep up on the latest information on all kinds of plastic stabilisation then why not review the selection of abstracts below and read on to find out about our 'Stabilisers for Plastics bulletin'.
Abstracts
Please see below a selection of abstracts highlighted in the October Newsletter. These are records which relate to plastics stabilisers 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.
1090900 - WORLD TRENDS IN PET PACKAGING
Apart from its excellent performance properties, PETP packaging market growth was also supported by the environmental credentials of PETP as a lightweight material that can be recycled easily. However, growth in the PETP packaging market has been curtailed since 2008 as a result of the world economic recession. PETP packaging market growth in tonnage terms has also been adversely affected by the trend to light-weight PETP bottles and the growing use of recycled PETP content in beverage bottles. While from 2010 to 2015, PETP packaging is unlikely to register growth rates similar to those seen between 2000 and 2007, growth opportunities still remain. Barrier PETP bottles and jars for juice, milk, tea, beer, wine and food are forecast to register strong growth over the period 2010-15. The developing countries of Asia Pacific, South America and Eastern Europe will also show higher growth for PETP packaging as a result of growing real incomes and the replacement of traditional pack formats by PETP bottles.
PETplanet insider, 12, No.9, 2011, p.14-16, ISSN: 1438-945
1090905 - STABILIZATION OF GREENHOUSES FILMS UNDER SEVERE TREATMENT WITH PESTICIDES: THE EFFECT OF UV ABSORBERS ON THE DEGRADATION RATE
The stabilisation of agricultural films against photodegradation is still the challenging target of the agrifilm market. There are many inherent and environmental factors that may affect the service life of greenhouse films. Among them are agrochemicals that can deactivate the UV stabilising system and significantly reduce the lifetime of the film. In this work, an evaluation and comparative study of different light stabiliser systems for greenhouse films subjected to drastic sulphur treatment is presented. The effect of UV absorbers on the degradation rate of agricultural films is investigated under artificial and natural weathering conditions. Film degradation is monitored through the changes in the mechanical and spectroscopic properties of the films. In given studies, a significant increase of the greenhouse film's life was observed for the TRZIII/HALS combination. The superior performance of TRZIII was attributed to the slow loss rate of UV absorber from the polymer matrix under artificial weathering and in field trials.
Plasticulture, 12, No.130, 2011, p.24-33, ISSN: 0257-9022
Schwartz H; Dolev U
1091400 - MECHANICAL PROPERTIES AND SOLID-STATE STRUCTURE OF PHOTODEGRADED POLYOXYMETHYLENE AND EFFECT OF UV STABILIZERS MODIFICATION
Ultraviolet (UV) light exposure can lead to photodegradation of polyoxymethylene (POM), resulting in a change of its physical and chemical properties. Benzophenone UV absorber (UV-9), benzotriazole light stabiliser (UV-327), and hindered amine light stabiliser (LD-622) were used as UV stabilisers to improve the photostabilisation of POM. Differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD) were employed to characterize POM before and after ageing. The change of its solid-state structure during the ageing process was investigated. The surface molecular weight and the mechanical properties of modified POM after UV ageing were also determined. The results showed that the degradation of amorphous molecules mainly occurred at the surface, while crystalline reorganisation occurred in the interior part of the sample as a result of the UV irradiation, both of which led to an increase of the crystallinity. After UV irradiation for 1000 h, the elongation at break and notched Charpy impact strength were only 16.6% and 27.4% of the initial sample, respectively. However, 1%-3% of the additives could reduce the chain scission and restrain the recrystallisation of POM after UV irradiation. Furthermore, mechanical properties were maintained to a certain degree by adding the UV stabilisers. 11 refs.
Journal of Macromolecular Science, Part B, 50, No.8, August 2011, p.1521-1534, ISSN: 0022-2348, DOI: 10.1080/00222348.2011.575028
Wu Guibo; Lu Chengxiang; Cai Xufu; Ren Xiancheng
1091584 - MONITORING THE INFLUENCE OF DIFFERENT WEATHERING CONDITIONS ON POLYETHYLENE PIPES BY IR-MICROSCOPY
Plastic pipes are often exposed to a range of environmental conditions which may lead to their degradation. The most important influence factors are UV radiation, humidity and temperature. These can cause leaching of long-term and light stabilisers and finally oxidation of the polymer. In this study we demonstrate how the elemental steps of the photooxidative degradation of polyethylene pipes can be monitored by IR-microscopy. In detail the influence of UV radiation leads to a depletion of the phenolic long-term stabiliser, Irganox 1010. Calibration of the spectroscopic data enables IR-microscopy to be carried out in a quantitative manner and the rate constants for the stabiliser loss to be calculated for the first time. The results obtained from IR-microscopy are well in agreement with those obtained by mechanical sample preparation and measurement of the oxidative induction time (OIT) as well as extraction coupled with chromatographic analysis (HPLC). A mechanism based on Norrish type cleavage is proposed. Also the formation of trans-vinylidene groups as unsaturated degradation products of the PE can be observed. In summary it can be shown that IR-microscopy is highly superior to the conventional approach of mechanical sample preparation with regard to spatial resolution and offers the advantage of being less labour intensive. 43 refs. Copyright (c) 2011 Elsevier Ltd.
Polymer Degradation and Stability, 96, No.10, 2011, p.1901-1910, ISSN: 0141-3910, DOI: 10.1016/j.polymdegradstab.2011.07.004
Maria R; Rode K; Brull R; Dorbath F; Baudrit B; Bastian M; Brendle E
1091842 - GREENHOUSES NEED SUN PROTECTION TOO (Free Access to Full Text)
Introduced in this long press release is a new light stabiliser from BASF, intended especially for addition to PE greenhouse films, to protect them from weathering caused by intense UV radiation from the sun, and by the heat developing at the contact points with metallic greenhouse frames. Extensive field trials of PE films containing new "Tinuvin XT 200" have also demonstrated good resistance to the acidic chemicals that can accumulate at the contact points of film and metal or wooden frames. Full details can be found here.
BASF, 20th September 2011
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