Search results for "Polymer blend"
showing 10 items of 219 documents
Diene/polar monomer copolymers, compatibilisers for polar/non-polar polymer blends. A controlled block copolymerisation with a single-site component …
2002
A well-controlled two-step process, the polymerisation of isoprene or isoprene/hex-1-ene copolymerisation followed by e-caprolactone polymerisation, affords trans-polyisoprene or (trans-polyisoprene/hex-1-ene copolymer)–poly(e-caprolactone) diblocks of various lengths. The single component initiator is an allylsamarocene compound. An atomic force microscopy study shows that these copolymers are efficient compatibilisers for poly(e-caprolactone) and polyisoprene blends. Poly(e-caprolactone) chain growth from Sm–polyisoprene chain.
Phase behaviour and interfacial tension of polysiloxane blends
1998
Abstract The cloud point curve for blends of poly(dimethyisiloxane) (PDMS, M w = 2.5kg mol −1 ) and poly(hexylmethylsiloxane) (PHMS, M w = 113kg mol − ] was determined turbidimetrically. The system demixes upon cooling and the UCST amounts to 36°C. The interfacial tension γ was determined at the critical composition for three temperatures by means of a spinning drop tensiometer. The dependence of γ on the reduced critical temperature can be described within experimental error by both the mean field theory and the Ising-3D theory.
Crystallization kinetics of poly(ethylene oxide) from its melt and from mixtures with tetrahydronaphthalene and oligo(ethylene oxide-block-dimethylsi…
2004
The crystallization of poly(ethylene oxide) (PEO) from the pure state and from its mixtures with oligo(dimethyl siloxane-b-ethylene oxide) (COP) and tetrahy- dronaphthalene (THN) was investigated. The crystallization kinetics was studied iso- thermally and nonisothermally with an automated device that monitored the light passing through the corresponding liquids as functions of time and/or temperature. The rate was strongly influenced by the concentration of COP in the mixture. A substantial decrease in the induction time (the time required for the onset of crystallization) and a considerable shift in the crystallization temperature (the transition from a liquid state to a solid state) to h…
Thermodynamics of Phase Behavior in PEO/P(EO-b-DMS) Homopolymer and Block Co-Oligomer Mixtures under Pressure
2003
The cloud-point temperatures (T-cl's) of poly(ethylene oxide) (PEO) and poly(ethylene oxide)-block-polydimethylsiloxane (P(EO-b-DMS)) homopolymer and block-oligomer mixtures were determined by turbidity measurements over a range of temperatures (105 to 130degrees), pressures (1 to 800 bar), and compositions (10-40 wt.-% PEO). The system phase separates upon cooling and T-cl was found to decrease with an increase in pressure for a constant composition. In the absence of special effects, this finding indicates negative excess volumes. Special attention was paid to the demixing temperatures as a function of the pressure for the different polymer mixtures and the plots in the T-phi plane (where…
Orientation induced brittle – Ductile transition in a polyethylene/polyamide 6 blend
2014
Abstract Polyamide/polyolefin blends are of scientific and technological interest but, on the other hand, the different chemical nature of the two components makes them incompatible, resulting in unsatisfactory physical properties and making compatibilization necessary. In particular, although the two components are ductile, the binary blends can show brittle behaviour. It is also known that the effect of the elongational flow (and then of the induced orientation) on polymer blends is a decrease of elongation at break with increase of the degree of orientation. In this work, the effect of orientation on the mechanical properties of a low density polyethylene/polyamide 6 incompatible blend w…
Processing – morphology – property relationships of polyamide 6/polyethylene blend–clay nanocomposites
2013
In this work, we studied the effect of the method of preparation and of reprocessing on the morphology and, con- sequently, on the physical properties of polyamide 6 (PA6)/ high density polyethylene (HDPE)-clay nanocomposite blends in the presence of different compatibilizers. In particular, the nanocomposites were obtained by melt mixing using a co- rotating twin screw extruder (E1). The blends thus obtained were re-extruded (E2) under the same operating conditions. Moreover, blends with the same final composition were produced using a masterbatch of the compatibilizer with the clay prepared in a separated stage in a batch mixer (MB). All the materials were characterized by scanning electr…
Blends of polyamide 6 and linear low density polyethylene functionalized with methacrylic acid derivatives
1997
Abstract Morphological, calorimetric, rheological, dielectric and mechanical behaviour of blends made with polyamide 6 (PA6) and linear low density polyethylene (PE) are presented. The PE was functionalized grafting ester and alcohol groups in a Brabender mixer with methacrylic acid derivatives. These groups induce “compatibilization” effects in the blends with respect to blends made with the unfunctionalized polyethylene. The difference effects on the behaviour of the blends of the various functional groups are shown. In particular, the interactions at the interface change depending on the chemical nature of the grafted groups. Ethyl and isobuthyl-methacrylate essentially cause dipolar int…
TI: Compatibilization of PA6/rubber blends by using an oxazoline functionalized rubber
2003
The compatibilization of blends of polyamide 6 with a nitrile butadiene rubber has been investigated. The procedure consists of two steps: modification of the nitrile groups of the rubber into oxazoline in the melt through condensation of ethanolamine with formation of a molecule of ammonia, followed by use of the modified rubber as a compatibilizing precursor which is melt mixed with the polyamide to produce the compatibilized blend. The modification reaction has been detected by NMR analysis and a rheological, mechanical and thermomechanical characterization has been carried out on the all the blends. The results indicate that the modification reaction occurs but the conversion of nitrile…
Compatibility of a statistical copolymer P(EMA-co-MMA) with PS and PMMA
1999
The compositions of coexisting phases and the interface widths in blends of a statistical copolymer of poly(ethylmethacrylate-co -methylmethacrylate) (P(EMA 1-x -co-MMA x )) and a deuterated polystyrene (PS(D)) as well as a deuterated poly(methylmethacrylate) (PMMA(D)) have been investigated by neutron reflectometry (NR). Interaction parameters are calculated from the compositions of coexisting phases and the interface width values. Utilizing a novel two dimensional scheme for graphical representation of the interaction parameters, the results are in very good agreement with studies on the interaction parameters for PS/PMMA, PS/PEMA and PEMA/PMMA blends. In particular, χ EMA/MMA deduced fro…
On the Preparation and Characterization of Polyethylene/Polyamide Blends by Melt Processing in the Presence of an Ethylene/Acrylic Acid Copolymer and…
2006
Samples of HDPE and PA6 have been melt-processed in the presence of two new phosphazene compounds, CP-2EPOX and CP-20XA together with an ethylene/acrylic acid copolymer. The blends have been prepared in an industrial twin-screw extruder by using PA6 and PE in weight ratios of 25/75 and 75/25. When used, 5 phr of EAA and 0.2 phr of CP have been added. The materials have been completely characterized from a rheological, morphological, and mechanical point of view. The results indicate that the additives used caused an increase in the rupture tensile properties, of the impact strength and viscosity especially in the PE-rich blend in the presence of CP-2EPOX. This result can be attributed both …