Polymer Journals

Polymers and Polymer Composites

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

Back  Search



Title: AN INVESTIGATION OF THE ELECTROMAGNETIC SHIELDING EFFECTIVENESS OF ETHYLENE VINYL ACETATE ELASTOMER REINFORCED WITH CARBON NANOFILLERS
Page Range: p.59-65
Author(s): Ray M; George J J; Chakraborty A; Bhowmick A K
File size: 276K
Download the pdf (subscribers only)
Buy the pdf (non-subscribers)
Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 18
Issue No: No.2

Abstract
An EVA-carbon nanofibre (CNF) nanocomposite was developed and its electromagnetic interference (EMI) shielding effectiveness (SE) was measured in the frequency range of 8-12 GHz. The dependence of SE on the applied electromagnetic frequency and the amount of filler loading was evaluated. The SE of the composites was found to be directly proportional to the applied electromagnetic frequency and the amount of filler. Incorporation of 16 wt % of CNF produced the optimum SE. The AC conductivity of the CNF-reinforced EVA composites was also measured in order to correlate the conductivity values with the SE of the respective composites. The level of filler loading governed the conductive network formation and hence the SE and conductivity. In order to perform a comparative study of SE, three other carbon-based nanofillers, i.e. multiwalled carbon nanotube, expanded graphite and conductive carbon black, were used. Morphological studies using TEM supported various findings. These results indicate that CNF is an effective filler for the development of composites with excellent EMI shielding capability. 21 refs.

Title: MECHANICAL, THERMAL AND RHEOLOGICAL PROPERTIES OF POLYPROPYLENE/WHEAT STRAW COMPOSITES AND STUDY OF THE EFFECT OF NANOCLAY ON THEIR MECHANICAL PROPERTIES
Page Range: p.67-73
Author(s): Hashemi S A; Esfandeh M; Mohammadi J
File size: 240K
Download the pdf (subscribers only)
Buy the pdf (non-subscribers)
Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 18
Issue No: No.2

Abstract
The possibility of using wheat straw fibres as a reinforcing filler in PP was examined. Untreated and silane-treated fibres having a variety of fibre lengths were used, at various fibre contents, to reinforce PP. Composites were tested for their mechanical, thermal and rheological properties, and the assessment of the adhesion at the interface was made via observations by SEM. The results showed that, for untreated fibres, an increase in fibre content up to 20 wt % led to an increase in the TS of the composite. Beyond this amount, however, TS decreased. On the other hand, the tensile modulus increased due to higher stiffness of the fibres. By using silane-treated fibres, both TS and modulus increased, but the viscosity was reduced because of better dispersion of the treated fibres. On addition of nanoclay, the mechanical properties of the composites, compared with the pure polymer, increased up to a particular fibre content, and after that the trend was reversed. 24 refs.

Title: MICROSTRUCTURAL STUDIES OF CEMENT COMPOSITES OF THERMOPLASTICS
Page Range: p.75-83
Author(s): Nair P S; Thachil E T
File size: 367K
Download the pdf (subscribers only)
Buy the pdf (non-subscribers)
Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 18
Issue No: No.2

Abstract
An attempt was made to explain the morphology and nature of interactions between the cement particles and thermoplastics in polymer-cement composites. All the thermoplastics (PVAl, polyethylene glycol, PVAc, acrylic polymer, acrylic-styrene polymer) were added to the cement paste either as water solutions or emulsions with calcium chloride as an accelerator for hydration of the cement particles. Thermal analysis, soxhlet extraction and SEM were some of the techniques employed to investigate the microstructure. The analysis revealed that the thermoplastics formed a film around the cement particles, thereby preventing the leaching of the water-soluble components which were present in the cement matrix. As the polymers are added to the cement before cement hydration some of the polymers underwent interactions with the cement, resulting in the formation of chemical bonds between the two phases. This resulted in better durability properties when the composites were exposed to polluted chemical environments. 14 refs.

Title: PURIFICATION OF CARBON NANOTUBES AND ITS EFFECT ON THE PROPERTIES OF CARBON NANOTUBE/POLYANILINE NANOCOMPOSITES
Page Range: p.85-90
Author(s): Dongyu Zhao; Kai Su; Xuemei Gao; Xiangdong Liu; Yunfei Meng; Weishu Yuan
File size: 230K
Download the pdf (subscribers only)
Buy the pdf (non-subscribers)
Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 18
Issue No: No.2

Abstract
Multi-walled carbon nanotubes were purified by use of mixed acid (nitric and sulphuric acids). The multi-walled carbon nanotubes/polyaniline composite (MWCNTs/PANI) was prepared by in-situ polymerisation using aniline monomer and nanotubes in HCl solution. The content of MWCNTs in the samples was 0 to 20 wt %. The composites were characterised with respect to their structure, morphology, conductivity, mechanical properties and other properties. The results showed that the MWCNTs were well dispersed in water after purification. The interaction between PANI and MWCNTs was proved by FTIR spectrometry. The conductivity and the TS of the MWCNTs/PANI were markedly improved after purification. 23 refs.

Title: NUCLEATION EFFECT OF THERMOTROPIC LIQUID CRYSTALLINE POLYMER ON THE CRYSTALLIZATION OF POLY(epsilon-CAPROLACTONE)
Page Range: p.91-101
Author(s): Defeng Wu; Yisheng Zhang; Ming Zhang; Minge Gao
File size: 413K
Download the pdf (subscribers only)
Buy the pdf (non-subscribers)
Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 18
Issue No: No.2

Abstract
A thermotropic liquid crystalline polymer (TLCP, an ethylene terephthalate-hydroxybenzoic acid copolymer) was used as a nucleating agent to improve the crystallisation of poly(epsilon-caprolactone) (PCL). The PCL/TLCP blend with the maximum TLCP content of 10 wt % was prepared by melt mixing. The non-isothermal crystallisation behaviour of the PCL matrix was studied using DSC and polarised optical microscopy, and the crystallisation kinetics were then further analysed by methods including the Avrami, Ozawa, Mo, Ziabicki, Lauritzen-Hoffman and Kissinger models. The results showed that the presence of the solid TLCP particles could enhance crystallisation temperature of the PCL matrix even at very low content (1 wt %). Although the mobility of the PCL chain segments decreased with increasing TLCP content, heterogeneous nucleation by TLCP particles always played a dominant role in the overall crystallisation. The blends therefore showed higher crystallisation rates and ability than those of pure PCL. The kinetic analysis and the data obtained in this study could be useful to optimise the processing conditions and to improve the crystallisation of PCL. 53 refs.

Title: SOLVENT UPTAKE AND ACCELERATED SOLAR AGING STUDIES OF COTTON-POLYPROPYLENE COMMINGLED COMPOSITE SYSTEMS
Page Range: p.103-112
Author(s): Tomlal J E; Thomas P C; Jayanarayanan K; Mathew J; Joseph K
File size: 371K
Download the pdf (subscribers only)
Buy the pdf (non-subscribers)
Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 18
Issue No: No.2

Abstract
The solvent absorption of cotton/PP side-by-side commingled composites in different solvents was studied, together with its variation with factors such as chemical treatments, temperature and fibre content, and the extent of tensile property deterioration by solar radiation in a solar light concentrator and by water diffusion. It was observed that, although cotton is highly hydrophilic, the diffusion was a matrix-dominated phenomenon. The extent of moisture absorption increased with the fibre content but decreased on treatment with maleic anhydride-modified PP. The former added a greater number of hydrophilic hydroxyl groups while the latter consumed them and enhanced the fibre-matrix interfacial adhesion. Increase in temperature accelerated the rate of moisture absorption and reduced the time required for equilibrium swelling. Exposure to sunlight in solar concentrator adversely affected the mechanical properties such as tensile strength and tensile modulus by weakening the fibre-matrix interfacial adhesion and by chain scission. 29 refs.

Title: EFFECT OF ALUMINA TRIHYDRATE AND BORAX ON FIRE RETARDANCY AND MECHANICAL PROPERTIES OF HIGH DENSITY POLYETHYLENE (HDPE) COMPOUNDS
Page Range: p.113-122
Author(s): Faghihi J; Morshedian J; Ahmadi S
File size: 458K
Download the pdf (subscribers only)
Buy the pdf (non-subscribers)
Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 18
Issue No: No.2

Abstract
The influence of inorganic flame retardants, including alumina trihydrate (ATH) and borax, on the mechanical properties and flammability of HDPE was studied. Results showed that an increase in the amount of flame retardant compounds caused a decrease in TS, ultimate strain and impact resistance. Use of EVA caused an increase in impact resistance compared with other compositions without EVA. Flammability test results showed an improvement in flame retardancy due to using ATH and borax. Composite containing EVA and borax showed better flammability properties compared with composite containing EVA and ATH because EVA as a compatibiliser could increase the stability of the borate component and form a glassy layer on the char, which resulted in an enhancement in the flammability properties. Furthermore, a synergistic effect was observed when ATH and borax were incorporated together. The charred layers provided a good thermal and flame barrier. Morphological, rheological and thermogravimetric analyses supported the idea that the improvement in the flame retardancy was due to charred layers formed by the ignition of inorganic flame retardant and polymeric matrix. 21 refs.

%>