Search results for "Polymer blend"

Thermal and elastic properties of poly(vinyl chloride) (PVC) + chlorinated polyethylene (CPE) blends

2003

Eight types of PVC + CPE blends with different weight ratios (PVC/CPE = 100/0, 90/10, 80/20, 60/40, 40/60, 20/80, 10/90, and 0/100) are tested. Data on the heat conductivity, thermal diffusivity, and heat capacity of the blends investigated are reported. Primary attention is paid to the structural approach for effective elastic constants: bulk, shear, and Young's modulae. The blends are considered as random mixtures of two isotropic constituents. It is found that the elastic moduli may be well represented by the Kerner and Budiansky equations.

Morphology and thermal properties of foams prepared via thermally induced phase separation based on polylactic acid blends

2012

Blends of poly-l-lactic acid with two different types of polylactic acid with different average molecular weights (50,000 and 175,000 g/mol, respectively) in different proportions (90/10, 80/20 and 70/30) were utilized in order to produce biodegradable and biocompatible scaffolds for soft tissue engineering applications. The scaffolds were produced via thermally induced phase separation starting from ternary systems where dioxane was the solvent and water the non-solvent. Morphology (average pore size and interconnection) was evaluated by scanning electron microscopy. Foams apparent density was also evaluated (porosity ranges from 87% to 92%). Moreover, a differential scanning calorimetry …

Rheological properties and morphology in LLDPE and PC based blends

1990

Abstract During an interlaboratory project on polymer blends (Technical Working Party-Polymer Blends-VAMAS), the rheological characteristics of some samples of blends of polycarbonate with linear low density polyethylene have been evaluated with the aid of a capillary rheometer. Some morphological observations on the extruded samples have also been performed through SEM and an attempt has been made to correlate the macroscopic and microscopic results.

Building Bridges by Blending: Morphology and Mechanical Properties of Binary Tapered Diblock/Multiblock Copolymer Blends

2021

Compatibilized Polyamide 6/Polyethylene Blends Clay Nanocomposites: Effect of the Degradation and Stabilization of the Clay Modifier

2008

Abstract Blends of polyamide 6 (PA6) and high-density polyethylene (HDPE) were compatibilized using an already investigated method and a sample of Cloisite 15A, a montmorillonite modified with ammonium quaternary salts was added. The blends were prepared in a twin screw extruder and characterized from a morphological, rheological and mechanical point of view. The results indicated that, despite a good morphology achieved in the filled blends and a moderate intercalation of the clay, the mechanical properties are far from being good, especially the ultimate properties. In order to investigate the possible influence of the inhibition of the crystallization and of the degradation of the organi…

The role of organoclay and matrix type in photo-oxidation of polyolefin/clay nanocomposite films

2009

Abstract In this paper the photo-oxidation behaviour of polyolefin/clay nanocomposite films was studied; in particular, the effect of the amount of organo-modifier and the matrix polarity on the photo-oxidation was investigated. Two different organo-modified clays and compositions of LDPE/EVA blend films were used and the photo-oxidation was followed by mechanical and spectroscopic analyses. The organoclay and matrix type strongly influence the photo-oxidative behaviour of nanocomposite films. The films filled with CL15A show a faster loss of mechanical performance and higher carbonyl formation with respect to the films filled with the CL20A. Additionally, the LDPE based nanocomposite under…

Mechanical properties of the nanometer scale pre-crystalline order of a poly (ethylene terepthalate) / poly (ethylene naphthalene) blend

2006

A previous study carried out on PET has shown that this polymer undergoes a continuous structural modification over a wide cooling rate interval when solidified from the melt[1] assuming a semi-crystalline structure below 2 K s 1 and a completely amorphous one above 100 K s 1. Most important was the existence of a state of intermediate order between the above cooling rates which was evidenced by the absence of crystalline reflections in the WAXS patterns and the occurrence of SAXS maxima[2] and exothermic peak areas (DSC) in the cooling rate range above 2 K s 1. Microhardness (MH) measurements revealed that this phase affects the mechanical properties[3] plausible if one thinks of crystalli…

The solidification behavior of a PBT/PET blend over a wide range of cooling rate

2009

In recent years, much attention has been paid to the development of high-performance polyester blends, among which blends of polybutylene terephthalate/polyethylene terephthalate (PBT/PET) are expected to exhibit remarkable properties as far as their crystallization behavior is concerned. Through trial and error, appropriate commercial compositions have been chosen which could not be otherwise explained by a suitable interpretation of the mechanisms determining their solidification behavior. The solidification behavior of a 60/40 w/w PBT/PET blend was studied in a wide range of cooling conditions, according to a continuous cooling transformation (CCT) procedure developed previously, aiming …

Rheology-morphology relationships in nylon 6/liquid-crystalline polymer blends

1990

Extrusion measurements have been carried out on blends of nylon 6 and a liquid-crystalline copolyesteramide (LCP). The flow curves at low temperature show a behavior similar to that of pure LCP with a rapid rise of the viscosity at low shear rates. At high shear rates the viscosity is lower than that for each of the two components. This minimum has been attributed to the lack of interactions between the two phases and to the formation of fibrils of the LCP phase. The SEM analysis shows, indeed, that fibrils of the LCP phase are produced in the convergent flow at the inlet of the capillary at high shear rates. These fibrils are lost during the flow in the long capillary.

Formulation, Characterization and Optimization of the Processing Conditions of Blends of Recycled Polyethylene and Ground Tyre Rubbers: Mechanical an…

2005

Abstract Recycling represents a valid alternative to the disposal of post-consumer plastics in common landfills if it is possible to obtain new materials with good final properties compatible with practical application and, above all, by using cheap methods. In this work the possibility to produce secondary materials by blending recycled polyethylene (RPE) coming from greenhouses and post-consumer ground tyre rubber (GTR) has been studied. In particular, the preparation of these blends has been carried out in a common industrial twin screw extruder. RPE pellets and GTR powder were fed to the extruder without any other additive. Temperature, processing speed, mixing procedure and composition…