Abstract Studies of the thermal and photodegradation two commercial polymers, stabilized unstabilized low‐density polyethylene, show effects weathering on differential scanning calorimetry (DSC) curves. The shape size melting peak vary significantly in aging accelerated photoirradiation, but no change was observed natural weathering, implying that crystallinity remains steady outdoor exposures. temperatures remain for all exposure tests. fall mechanical properties evolution chemical...

Abstract This work analyzes the influence of thermal degradation on microstructure and mechanical properties low‐density polyethylene subjected to aging at 70°C in dark for times up 21 months. It is found that polymer shows a gradual increase its elastic modulus dramatic reduction ductility, due secondary crystallization. Infrared spectroscopy (FTIR) reveals autoaccelerated oxidation after 5 months aging. observed unsaturated vinylidene groups initially present material are gradually...

This study demonstrates the successful application of machine learning for hydrogenolysis reaction. The prediction more than a million generated experiments opens way to identify potentially best catalyst in specified range.

Abstract Blown extruded films of low‐density polyethylene (LDPE) have been subjected to climatic ageing in a sub‐Saharan facility at Laghouat (Algeria) with direct exposure sun. Samples were characterized by complementary techniques after prescribed amounts time up 8 months. It was shown tensile testing that the mechanical properties are quite sensitive ageing: (i) elastic modulus increases and saturates, (ii) stress slightly, (iii) rupture energy decreases dramatically 4 months weathering....

This study deals with the photodegradation of polyethylene films for greenhouse covering. The UV range solar light appears as most deleterious factor plastic degradation in outdoor exposure. reasons this photosensitivity are structural defects which absorbing. use FTIR an investigation tools has revealed that material reacts surrounding oxygen via a photooxidation process. Although, photochemical process is quite complex it through than crosslinking and chain scissions important events...

This study deals with the photodegradation of polyethylene films for greenhouse covering. The UV range solar light appears as most deleterious factor plastic degradation in outdoor exposure. reasons this photosensitivity are structural defects which absorbing. use FTIR an investigation tools has revealed that material reacts surrounding oxygen via a photooxidation process. Although, photochemical process is quite complex it through than crosslinking and chain scissions important events...

Thermal aging below the glass transition temperature (Tg), during three months, of Poly (vinyl chloride) (PVC) under its different aspects, powder (p-PVC), dry-blend and Unplasticized (u-PVC) or rigid form was performed.The stabilizing system used is a commercial compound constituted by lead based stabilizers, internal external lubricants.The ageing PVC these aspects performed in thermo-regulated oven at 60 °C, close ground Sub-Sahara region (Ghardaï a, Algeria).A sampling regular interval...

Blown extruded films of low-density polyethylene (LDPE) have been subjected to climatic ageing in a sub-Saharan facility at Laghouat (Algeria) with direct exposure sun. Samples were characterized by X-ray diffraction (XRD) and differential scanning calorimetry (DSC) techniques after prescribed amounts time up 8 months. It has shown via these two that crystallinity increases time. The reason morphological changes is relevant photooxidative reactions leading crosslinking the beginning chain...

Abstract Blown extruded polyethylene films without stabilizers have been exposed outdoors under severe weathering conditions in the Sahara. The chemical aspect of aging has followed by IR spectroscopy. mechanical monitored means a nondestructive method. It consists measuring velocities and attenuations ultrasonic waves propagating several directions film plane. Stiffness constants energy dissipation terms calculated. From results obtained it is shown that stiffening material leads to an...

Weathering of LDPE films was performed in a sub-Saharan facility Laghouat, Algeria. Ageing led to rapid change the physicochemical properties resulting from alteration material's microstructure. XRD revealed progressive increase crystallinity ratio and thickness crystalline lamellae as well. SEM presence white particles, which look like phase emerging surface film. The oxidation varied according concentration gradient across thickness. impact microstructural changes on mechanical highlighted...

ABSTRACT Low density polyethylene films used for greenhouse covering were naturally weathered 6 months in sub‐Saharan region (Algeria). The microstructural and morphological changes have been checked by infrared spectroscopy. of the mechanical properties followed tensile creep‐recovery tests. measurements carried out two main directions film plane. Besides oxidation, chain scission crosslinking are competing during all ageing protocol, affecting thereby, as well viscoelastic behavior...

This work evaluates the possibility of using nickel-containing structured glass fiber catalysts (Ni/GFC) for process hydrogenolysis gas condensate (GC) into transportable components natural gas, which will increase efficiency GC processing and contribute to development more cost-effective technologies in oil-gas industry. Ni/GFC samples with Ni content 5, 10 15% wt. were synthesized by surface thermal synthesis (STS). An industrial granular catalyst a mass 16% was used compare catalytic...

Thermal aging of standard samples rigid PVC (u-PVC) taken from plastic tubes near and above the glass transition temperature (Tg) was used to investigate effect elevated temperatures on mechanical properties in industrial areas. Three protocols were used, each lasting 90 days at 80 °C, 100 120 °C. Crosslinking chain scission reactions changed tensile properties, either increasing them or decreasing them. For all three protocols, it discovered that Young's modulus increased with time....