Organoclays: Properties, preparation and applications

Fabrication of superhydrophobic/superoleophilic cotton for application in the field of water/oil separation.

PET/montmorillonite (MMT) nanocomposites were prepared via melt-blending and its nano-dispersion morphology was confirmed by X-ray diffraction and transmission electron microscopy. Its non-isothermal crystallization behavior was studied by DSC. It is found that the crystallization rate of PET nanocomposite was increased significantly. The Avrami equation parameters related to crystallization, such as n , Z c and t 1/2 , were calculated and analyzed. The thermal property and mechanical property of the composite were studied. When the MMT content was 1%, the composite has a desired comprehensive property. At this composition, the thermal degradation onset temperature and the thermal deformation temperature of PET were increased by 12 and 35 °C, respectively, and the tensile strength of the PET was increased by 25% with slightly increase of the notched impact strength.

Study on mechanical properties, thermal stability and crystallization behavior of PET/MMT nanocomposites

Fabrication of superhydrophobic wood surface by a sol–gel process

The effect of organic modifier of the clay on morphology and crystallization properties of PET nanocomposites

In this work, a detailed investigation of the rheological and mechanical properties of nanocomposites based on polyethylene terephthalate (PET) and montmorillonite clays is presented. A series of additives [maleic anhydride (MAH), pentaerythritol (PENTA), and alkylammonium chlorides from amines of various chain lengths] were used as compatibilizers. The influence of the additives on the mechanical and rheological behavior of the PET matrix was evaluated separately, through their individual contributions. To shed more light on the reported decrease in melt viscosity of organoclay composites with respect to the matrix viscosity, observed in nylon and PET nanocomposites, the polymer molecular weight was related to the resulting rheological and mechanical properties of the systems. Results reveal that the PET nanocomposites behave quite differently in shear as opposed to elongation. The viscoelastic properties in shear present low values when the molecular weight decreases because of the processing operations. However, properties under tension increase over those of the matrix, manifesting the presence of a network formed between the clay and the polymer.

Mechanical and rheological studies on polyethylene terephthalate-montmorillonite nanocomposites

Colloidal aggregation phenomena: Spatial structuring of TEOS-derived silica aerogels.

On the influence of sands on low density polyethylene photodegradation

The mixing of incompatible polymers such as polyethylene terephthalate (PET) and styrene-butadiene rubber (SBR) produces a blend with poor mechanical and impact properties, because polymeric phases interact weakly with each other and segregate. The use of SBR grafted with maleic anhydride (MAH) increases the compatibility of the SBR-PET system by generating higher interactions and chemical links between the ingredients of the blend. The induced compatibility is reflected in the 2.5-fold increase in the impact resistance of the blend as compared to that of pure PET. The grafting reaction to produce SBR-g-MAH is carried out by reactive extrusion using a reaction initiator, benzoyl peroxide (BPO), and the extent of the reaction depends on the concentration of MAH and BPO. Results indicate the close relationship between processing conditions and microstructural parameters, such as particle diameter and interparticle distances of the dispersed rubber phase, necessary to achieve the optimum impact resistance.

On the properties and processing of polyethylene terephthalate/styrene-butadiene rubber blend

In the present work, an analysis is carried out to provide a relationship between the Molecular Weight (Mw) of degraded LDPE films (containing Mn stearate as pro oxidant (MnSt-LDPE) and changes in viscosity, elongation at break (EB %) and carbonyl index (CI) occurring during thermal degradation in the thermophilic phase of the compost process. The thermal treatment comprised various temperatures (50°C, 60°C, and 70°C) and exposure times, and was characterized through a so-called Energy-Time Factor (the product of thermal energy and exposure time). Changes in viscosity, EB %, and CI were correlated to this factor. A modified Mark-Houwink equation was used to relate the zero shear-rate viscosity and Mw of the degraded LDPE films. Results indicate that the EB %, Mw and viscosity decrease simultaneously with an increase in the CI as the Energy-Time Factor augments, allowing the assessment of the variation of these properties with Mw. Calculations of the percentage abiotic degradation (%D) of LDPE films indicate that a Mw of 6 kg mol−1 corresponds to a maximum abiotic degradation degree of 91.85%, which is henceforth susceptible to biodegradation. The film treated with Energy-Time Factor of 2.79E+09 J s mol−1 reached a 74% of biodegradation in 90 days (average time of the composting process). Results exhibit clearly the correlation between abiotic and biotic degradation. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42721.

Degradation and biodegradation of polyethylene with pro‐oxidant aditives under compost conditions establishing relationships between physicochemical and rheological parameters

Mirna R. Estrada

Papers

Mechanical and rheological studies on polyethylene terephthalate-montmorillonite nanocomposites

Colloidal aggregation phenomena: Spatial structuring of TEOS-derived silica aerogels.

On the influence of sands on low density polyethylene photodegradation

On the properties and processing of polyethylene terephthalate/styrene-butadiene rubber blend

Degradation and biodegradation of polyethylene with pro‐oxidant aditives under compost conditions establishing relationships between physicochemical and rheological parameters