Polymer Journals

Polymers and Polymer Composites

Logged into APC, CP, IPSAT, PPC, PRR, RRR & PRPRT.

Back  Search



Title: SYNTHESIS, MECHANISMS AND KINETICS OF FORMATION OF BI-COMPONENT POLYURETHANES
Page Range: p.645-665
Author(s): Ketata N; Sanglar C; Waton H; Alamercery S; Delolme F; Paisse O; Raffin G; Grenier-Loustalot M F
File size: 357K
Download the pdf (subscribers only)
Buy the pdf (non-subscribers)
Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 12
Issue No: No. 8

Abstract
The polyaddition reactions of bi-component polyurethane systems are characterised in this work. In order to characterise the reactivities of different polyethers towards 4,4'-diphenylmethane-diisocyanate, the mechanisms and kinetics of formation of polyurethanes were modelled by using the p-tolylisocyanate. Two types of polyethers were used: polyethylene glycol and polypropylene glycol with variable macromolecular chains and structures. The results were obtained by using a variety of analytical techniques, (NMR, FTIR, HPLC/UV/MS, ESI/MS, DSC, and MALDI-TOF). This work illustrates the need to use several complementary techniques in order to understand the molten state reaction mechanisms and kinetics of these complex PU systems. 30 refs.

Title: COMPARATIVE RHEOLOGICAL PROPERTIES OF DOPE SOLUTIONS OF HIGH MOLAR-MASS POLY(ACRYLONITRILE-CO-METHYLACRYLATE-CO-ITACONIC ACID)
Page Range: p.667-677
Author(s): Devasia R; Nair C P R; Ninan K N
File size: 244K
Download the pdf (subscribers only)
Buy the pdf (non-subscribers)
Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 12
Issue No: No. 8

Abstract
The rheological behaviour of a dope solution of poly(acrylonitrile-co-itaconic acid) copolymer was compared with that of a poly(acrylonitrile-co-methylacrylate-co-itaconic acid) terpolymer of identical molecular weight. The effects of temperature, concentration and shear force on the rheology of the polymer dope were examined. It was found that in both cases, the temperature dependence of zero shear viscosity conformed to the Arrhenius-Frenkel-Eyring equation. The free energy change increased with concentration more significantly for the copolymer than the terpolymer. The Power Law model was fitted to the shear dependency of the viscosity, and the pseudoplasticity index was shown to decrease with the dope concentration. The shear thinning behaviour was more pronounced for the terpolymer than the copolymer. Empirical models were derived which were able to predict the pseudoplasticity index value of the polymers of a given viscosity-average molecular weight at any concentration and temperature. The onset of shear thinning shifted to a lower shear regime with an increase in solid concentration. 26 refs.

Title: MULTI-RESPONSE OPTIMIZATION OF PC/ABS BLENDS USING PRINCIPAL COMPONENT ANALYSIS
Page Range: p.679-688
Author(s): Chin-Ping Fung; Po-Chung Kang
File size: 114K
Download the pdf (subscribers only)
Buy the pdf (non-subscribers)
Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 12
Issue No: No. 8

Abstract
This paper, using principal component analysis (PCA) based on the Taguchi method, presents the optimum levels of injection moulding parameters in relation to the mechanical properties of polycarbonate/ABS blends. The experiment design used an orthogonal array for the four controllable manufacturing process factors, namely, filling time, melt temperature, mould temperature, and packing pressure, each at three levels, to find the optimum process factor/level combination. The single-response optimisation of the mechanical properties was conducted using the Taguchi method. For a multi-response case, PCA was employed to transform the correlated principal properties to a set of uncorrelated principal components. The optimum process factor/level combination based on the first principal component was determined first. Then the appropriate number of principal components extracted, and the impact of that number on the optimum process condition was investigated by extracting more than one principal component and integrating them into a comprehensive index. Finally, an analysis of variance was used to find the most influential injection moulding parameter for single and multiple response problems. Results are discussed. 20 refs.

Title: PLASMA TREATMENTS OF MELT-EXTRUDED BLEND SHEETS OF RECYCLED PET/POLY(EPSILON-CAPROLACTONE)
Page Range: p.689-694
Author(s): Hirotsu T; Qi K; Nakayama K
File size: 335K
Download the pdf (subscribers only)
Buy the pdf (non-subscribers)
Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 12
Issue No: No. 8

Abstract
A plasma process was applied to the surface treatments of melt extruded sheets of blends of recycled PETP with polyepsilon-caprolactone, and the surface effects were investigated with regard to the changes in surface morphology and chemical structure. Plasmas of different reactivity were used: non-oxidative argon and nitrogen, and oxidative oxygen. Mass loss by etching and morphology changes to the surfaces were investigated with regard to the discharge power effects as well as the plasma gas source reactivity. The sheets of polyepsilon-caprolactone and polyepsilon-caprolactone-rich blends were found to be more susceptible to the oxidative plasmas, and resistant to the non-oxidative plasmas. The generation of microstructures was observed on wavy or granular forms of morphology of the original sheets after the plasma treatments, according to scanning probe microscopy observations. 15 refs.

Title: PREPARATION AND CHARACTERISATION OF POLYANILINE GRAFTED SILICA NANOPARTICLES
Page Range: p.695-698
Author(s): Liu Peng; Liu Weimin; Xue Qunji
File size: 182K
Download the pdf (subscribers only)
Buy the pdf (non-subscribers)
Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 12
Issue No: No. 8

Abstract
Polyaniline (PANI) was grafted covalently onto the surfaces of silica nanoparticles by a three-step method. PANI was grafted onto the surfaces of the phenylaminopropyl silica nanoparticles by the in-situ chemical oxidation of aniline with ammonium peroxydisulphate using a dispersion polymerisation method. A percentage of grafting of 234% and a grafting efficiency of 54.1% were achieved, calculated from the results of elemental analysis. The polyaniline grafted silica nanoparticles were also characterised by FT-IR, UV/vis, TEM, XPS and TGA. The four probe conductivities were also measured. The product is expected to be used in secondary batteries, biosensors, corrosion protection, and antistatic packaging materials. 6 refs.

Title: INVESTIGATION INTO POLYHYDROXYBUTYRATE MORPHOLOGY UNDER THE INFLUENCE OF VARYING SOLVENT TYPE
Page Range: p.699-703
Author(s): Sharma L; Nishida K; Kanaya T
File size: 170K
Download the pdf (subscribers only)
Buy the pdf (non-subscribers)
Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 12
Issue No: No. 8

Abstract
Polyhydroxybutyrate (PHB) is a bacterially synthesised biodegradable semi-crystalline which undergoes underpinning of spherulites during secondary crystallisation, causing severe cracking and rendering the material brittle. Brittleness can be reduced by the use of a plasticiser, and to this end, this paper investigates the influence of the solvent, (chloroform, acetone, and toluene) as a plasticiser, on PHB. PHB's crystalline and amorphous FTIR bands in the 950-1850 cm-1 region were studied. No band change was identified between the different solvent systems, indicating that the solvent was not an influencing factor in the formation of crystalline and amorphous regions in PHB. Hot stage optical microscopy was also used to further substantiate the FTIR studies. However, a marked change between the solvents and pure PHB became evident. The growth rate decreased for all solvents compared to the homopolymer, which is reported to indicate a non-plasticising effect. 19 refs.

Title: MORPHOLOGICAL CHARACTERISATION OF NATURAL FIBRE REINFORCED THERMOPLASTICS (NFRTP) PROCESSED BY EXTRUSION, COMPRESSION AND ROTATIONAL MOULDING
Page Range: p.705-718
Author(s): Torres F G; Diaz R M
File size: 661K
Download the pdf (subscribers only)
Buy the pdf (non-subscribers)
Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 12
Issue No: No. 8

Abstract
A methodology is described for applying conventional morphological characterisation techniques to some of the manufacturing processes of natural fibre reinforced thermoplastics (NFRTP). The composites studied consisted of matrices of PP or PE, and of discrete jute, sisal and other natural fibres as reinforcement. Various microscopic techniques were used to characterise the processing stages and the structure-property relationships during the manufacture of NFRTPs using single-screw extrusion, compression and rotational moulding. Attention was focussed on the fibre length distributions, fibre orientation and overall fibre dispersion in the matrix. In addition, transcrystallinity in the case of PP/sisal and PP/jute composites is also reported. The characterisation procedures described are related to the manufacturing processes studied in each case, and it is suggested that some or all of the techniques described could be implemented as quality control procedures in the manufacture of products using NFRTPs. 30 refs.

Title: CURING STUDY OF A TOUGHENED EPOXY SYSTEM USING THE DYNAMIC TORSIONAL VIBRATION METHOD
Page Range: p.719-726
Author(s): Chen Dazhu; Yuan Fang; He Pingsheng; Quian Jiasheng
File size: 178K
Download the pdf (subscribers only)
Buy the pdf (non-subscribers)
Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 12
Issue No: No. 8

Abstract
A study is reported of the cure kinetics of an epoxy/polyamide system using the dynamic torsional vibration method, by measuring the change in mechanical properties (torque) during the cure. The experimental data were analysed by the non-equilibrium thermodynamic fluctuation theory and the Avrami method. Results from dynamic mechanical thermal analysis indicated that the fully cured specimens of epoxy resin/polyamide exist in the rubbery plateau state at the applied cure temperature, and that with increasing cure temperature, the equilibrium torque dropped, the gel time decreased and the cure reaction took less time to complete. After the gel point, the same curing mechanism occurred at various cure temperatures. Also investigated was the effect of increasing the hardener concentration on the rate of crosslinking at a given cure temperature. Excess polyamide was shown to increase the number of crosslinking points, and hence, enlarged the Avrami exponent. 18 refs.

Title: STRUCTURE AND CRYSTALLIZATION BEHAVIOUR OF POLY(EPSILON-CAPROLACTONE)/CLAY INTERCALATED NANOCOMPOSITES
Page Range: p.727-737
Author(s): Kiersnowski A; Kozak M; Jurga S; Piglowski J
File size: 258K
Download the pdf (subscribers only)
Buy the pdf (non-subscribers)
Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 12
Issue No: No. 8

Abstract
Nanocomposites of polyepsilon-caprolactone(PCL)/M-HTAB were obtained by the polymerisation of caprolactone with various amounts of montmorillonite organophilised with hexadecyltrimethylammonium bromide (HTAB). A study was made of the microstructure of the nanocomposites using small angle X-ray scattering (SAXS). The melting enthalpies, the crystallinities and the half-time of isothermal crystallisation were evaluated by differential scanning calorimetry. As a result of SAXS experiments for the composite PCL/M-HTAB 90/10 in the temperature range from 313 to 283 K, a rapid change in the interlamellar distance from 3.1 nm to 2.72 nm was observed. Similar scattering curves were obtained for the nanocomposite PCL/M-HTAB 70/30. In the composites containing 50% and 64% wt of M-HTAB, the decrease in interlayer distance was seen to be less pronounced in the same temperature range. Differential scanning calorimetry results are claimed to show clearly that the crystallisation is divided into two separate process: primary crystallisation in the PCL matrix, and secondary crystallisation. 20 refs.

Title: EFFECTS OF SURFACE TREATMENT OF COBALT OXIDE PARTICLES ON THE PROPERTIES OF POLYMETHYLPHENYLSILOXANE BASED NANOCOMPOSITES
Page Range: p.739-747
Author(s): Sun J T; Huang Y D; Cao H L; Gong G F
File size: 168K
Download the pdf (subscribers only)
Buy the pdf (non-subscribers)
Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 12
Issue No: No. 8

Abstract
The objective of this study was to prepare a cobalt oxide/polymethylphenylsiloxane (PMPS) nanocomposite with excellent thermal and endothermal properties. The cobalt oxide nanoparticles were subjected to a grafting treatment with polybutylmethacrylate (PBMA) and then incorporated into heat-resistant polymethylphenylsiloxane. The effects of their grafting treatment on the properties of the nanocomposites were investigated and reported. Results of investigations carried out with a dynamic wetting instruments, transmission electron microscopy, differential thermogravimetry and by a calibration test of the heat flow transducer indicated that PBMA had been grafted onto the surfaces of the cobalt oxide nanoparticles successfully, and that the grafting ratio had reached around 6.6%. Compared with pure PMPS resin, the thermal stability of the untreated cobalt oxide/PMPS composites decreased, but increased for treated cobalt oxide/PMPS composites. The calibration test of the heat flow transducer revealed that the nanocomposite with grafted cobalt oxide nanoparticles had much better endothermal properties than the one with untreated nanoparticles. 26 refs.

%>