Eco-friendly approach and potential biodegradable polymer matrix for WPC composite materials in outdoor application

Blends based on high density polyethylene (HDPE) and poly(lactic) acid (PLA) with different ratios of both polymers were produced: a blend with equal amounts of HDPE and PLA, hence 50 wt.% each, proved to be a useful compromise, allowing a high amount of bio-derived charge without this being too detrimental for mechanical properties and considering its possibility to biodegradation behaviour in outdoor application. In this way, an optimal blend suitable to produce a composite with cellulosic fillers is proposed. In the selected polymer blend, wood flour (WF) was added as natural filler in the proportion of 20, 30 and 40 wt.%, considering as 100 the weight of the polymer blend matrix. Two compatibilizers to modify both HDPE-PLA blend and wood-flour/polymer interfaces i.e. polyethylene grafted maleic anhydride and a random copolymer of ethylene and glycidyl methacrylate. The most suitable percentage of compatibilizer for HDPE-PLA blends appears to be 3 wt.%, which was selected also for use with wood flour. In order to evaluate properties of blends and composites tensile tests, scanning electron microscopy, differential scanning calorimetry, thermo-gravimetric analyses and infrared spectroscopy have been performed. Wood flour seems to affect heavy blend behaviour in process production of material suggesting that future studies are needed to reduce defectiveness

Optimization of thermoplastic blend matrix HDPE/PLA with different types and levels of coupling agents

High-density polyethylene (HDPE) and poly(lactic) acid (PLA) blends with different ratios of both polymers, namely, 30:70, 50:50, and 70:30, were produced. Polyethylene-grafted maleic anhydride and a random copolymer of ethylene and glycidyl methacrylate were also considered as compatibilizers to modify HDPE/PLA optimal blends and were added in the amounts of 1, 3, and 5 wt.%. Different properties of the blends were evaluated by performing tensile tests and scanning electron microscopy to analyze blend and interfaces morphology. Moreover, thermomechanical analysis through differential scanning calorimetry, thermo-gravimetric analysis, and infrared spectroscopy were also performed. The blend containing equal amounts of HDPE and PLA seemed to present a good balance between amount of bio-derived charge and acceptable mechanical properties. This suggests that these blends have a good potential for the production of composites with lingo-cellulosic fillers

Alcohol and nicotine dependence in French seafarers

Background. To study the relationship between alcohol abuse or dependence as diagnosed by the CAGE questionnaire, and nicotine dependence as diagnosed by Fagerström Test of Nicotine Dependence (FTND) in French seamen. Materials and methods. French seamen were recruited from a stratified survey of 19 ports in France. The subjects completed a questionnaire during their annual medical check-up with occupational physicians and nurses of the Occupational Health Department (Service de santé des gens de mer). Findings. Approximately forty-four per cent of male subjects were current smokers, and approximately sixty-three per cent of these were nicotine dependent according to FTND. More than 11% of male subjects drank alcohol every day. About 16% of these were alcohol dependent according to CAGE. A strong positive relationship has been shown between alcohol dependence and nicotine dependence. There was a highly significant difference between alcohol dependent and non-alcohol dependent subjects in the FTND. Conversely, nicotine dependent and non-nicotine dependent subjects significantly differed regarding several alcohol-related variables. Conclusions. Alcohol and nicotine consumption is a major public health issue in seamen. A strong positive correlation was found between alcohol abuse or dependence and nicotine abuse or dependence. Some alcohol-related behaviours were associated with nicotine dependence, and some tobacco-related behaviours were also associated with alcohol dependence. These findings are novel for this kind of population in France. In view of these results, combined smoking cessation and alcohol consumption reduction policies should be developed in this population. Finally, future studies could analyze the work environment, which seems to be associated with consumption and dependency

Addition of X-ray fluorescent tracers into polymers, new technology for automatic sorting of plastics : proposal for selecting some relevant tracers

A description of a new technology for automatic sorting of plastics, based on X-ray fluorescence detection of tracers, added in such materials is presented. This study describes the criteria for the selection of tracers, and concluded that the most adapted for XRF are some rare earth oxides. The plastics chosen for tracing and identification are the ones contained in ELV and WEEE from which discrimination is difficult for the existing sorting techniques due to their black colour.A description of a new technology for automatic sorting of plastics, based on X-ray fluorescence detection of tracers, added in such materials is presented. This study describes the criteria for the selection of tracers, and concluded that the most adapted for XRF are some rare earth oxides. The plastics chosen for tracing and identification are the ones contained in ELV and WEEE from which discrimination is difficult for the existing sorting techniques due to their black colour

A study on the dispersion, preparation, characterization and photo-degradation of polypropylene traced with rare earth oxides

This research work deals with the effect of rare earth oxides on the PP matrix with respect to the thermal and mechanical properties and to the photo-degradation under UV irradiation exposure. The rare earth oxides are used as tracers for the identification of polymer materials, in order to have an economically efficient recycling and high speed automatic sorting of plastic wastes. The addition of 0.1 wt% of such particles of a micrometric size has a minor effect on the mechanical and thermal properties of the traced materials, as well as on the photo-degradation of the polymer after UV irradiation exposure. For 1 wt% tracer content, before UV irradiation treatment, the melting and crystallization temperatures as well as the thermal stability of the PP matrix are slightly increased, whereas the elongation at break decreases from 10 to 50% for a cross-head speed of 250 mm/min. However, the addition of 1 wt% of CeO2 improves the photo-degradation resistance of the PP matrix to UV exposure due to the UV light screening effects offered by these particles. The SEM images together with the results obtained from image processing show a homogenous dispersion of tracers in the PP matrix.This research work deals with the effect of rare earth oxides on the PP matrix with respect to the thermal and mechanical properties and to the photo-degradation under UV irradiation exposure. The rare earth oxides are used as tracers for the identification of polymer materials, in order to have an economically efficient recycling and high speed automatic sorting of plastic wastes. The addition of 0.1 wt% of such particles of a micrometric size has a minor effect on the mechanical and thermal properties of the traced materials, as well as on the photo-degradation of the polymer after UV irradiation exposure. For 1 wt% tracer content, before UV irradiation treatment, the melting and crystallization temperatures as well as the thermal stability of the PP matrix are slightly increased, whereas the elongation at break decreases from 10 to 50% for a cross-head speed of 250 mm/min. However, the addition of 1 wt% of CeO2 improves the photo-degradation resistance of the PP matrix to UV exposure due to the UV light screening effects offered by these particles. The SEM images together with the results obtained from image processing show a homogenous dispersion of tracers in the PP matrix