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1.
Med J Malaysia ; 59 Suppl B: 135-6, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15468855

RESUMO

Poly (p-phenylene vinylene) (PPV) was synthesized from p-xylylene bis(tetrahydrothiophenium chloride) using the Wessling route and characterized by Fourier Transform Infra-Red (FTIR) and UV-visible (UV-VIS) spectroscopic techniques. The significance of thermal treatment along with evolution of precursor polymer to polymer PPV was also studied through these spectroscopic techniques. Thermally Stimulated Current (TSC) measurements indicated the presence of crystallization, sulphonium group which occurred through the evolution from precursor polymer to polymer PPV during thermal treatment.


Assuntos
Polímeros/síntese química , Polivinil/síntese química , Humanos , Polímeros/análise , Polivinil/análise , Espectroscopia de Infravermelho com Transformada de Fourier
2.
Med J Malaysia ; 59 Suppl B: 139-40, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15468857

RESUMO

The aim of this work was to study radiation and the effects of temperature on conductivity properties of polyvinyl alcohol (PVA)-based potassium hydroxide (KOH) and propylene carbonate (PC), where the ionic conduction preferentially occurs in the amorphous phase by free radicals ions through gamma-irradiation. Alkaline composite polymer electrolyte (ACPE) consisting of PVA, KOH and PC of different concentration ratios were prepared by solvent-casting technique. The ACPE were irradiated with different doses from 5 kGy up to 200 kGy. The conductivity properties of the electrolyte films were measured at different frequencies in the range 20 Hz to 1 MHz using LCR meter. The results showed that the conductivity properties were dependent on the radiation dose, temperature and the concentration of the polymer blends.


Assuntos
Eletrólitos/efeitos da radiação , Hidróxidos/efeitos da radiação , Polímeros/efeitos da radiação , Álcool de Polivinil/efeitos da radiação , Compostos de Potássio/efeitos da radiação , Propano/análogos & derivados , Propano/efeitos da radiação , Temperatura , Relação Dose-Resposta à Radiação , Condutividade Elétrica , Eletroquímica , Raios gama , Humanos
3.
Med J Malaysia ; 59 Suppl B: 212-3, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15468893

RESUMO

The radiation-response characteristics of polymetharylic acid gel dosimeter prepared with different concentrations of monomer and cross-linker is described in these studies. The dosimeters were prepared under the hypoxic condition in a glove box and were then irradiated with gamma-rays produced by Co-60 radionuclide that was generated at 1.25MeV energy. The irradiation took place at different doses ranged from 0Gy to 19Gy. Due to the radiation activities, chain-reaction polymerisation processes had taken place in the formation of polymethacrylic acid (PMAA) gel, which cause the dose response mechanism increased in the NMR relaxation rates of protons. It has been observed that for higher concentration of monomer and cross-linker, the polymerization rate was increased.


Assuntos
Espectroscopia de Ressonância Magnética , Ácidos Polimetacrílicos/síntese química , Radiometria/instrumentação , Radioisótopos de Cobalto , Relação Dose-Resposta à Radiação , Raios gama , Géis , Humanos , Prótons , Sensibilidade e Especificidade
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