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Abstract  

The paper presents results of thermal properties measurements of cis-1,4-polybutadienes with different contents of cis-1,4 mers before and after their conventional cross-linking with the use of dicumyl peroxide and non-conventional cross-linking by means of iodoform. The measurements were carried out under the atmosphere of neutral gas using a micro-calorimeter, DSC and thermogravimetry, TG. The thermal curves have been interpreted from the point of view of phase transitions and chemical reactions of investigated elastomers.

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Abstract  

This article describes the test results of thermal properties and flammability of the unconventionally cross-linked blends of chlorosulfonated polyethylene (CSM) and butadiene–styrene rubber (SBR) by means of zinc oxide or nano-zinc oxide. The thermal curves have been interpreted from the point of view of the chemical transitions of elastomers and their blends. It has been found that the content of combined chlorine in CSM exerts a significant influence on the cross-linking kinetics of CSM/SBR blends, their thermal properties and flammability.

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Journal of Thermal Analysis and Calorimetry
Authors:
G. Janowska
,
A. Kucharska-Jastrzabek
,
A. Kasiczak
, and
W. M. Rzymski

Abstract

The article describes the measurement results of the thermal properties of cross-linked blends of carboxylated butadiene-acrylonitrile rubber (XNBR, Krynac X.7.50) and chlorosulfonated polyethylene (CSM, Hypalon 48) under inert gas (DSC, TG) and in air (derivatography). The blends were cross linked at a temperature of 150 °C by means of MgO in the presence of stearic acid. The thermal curves were interpreted from the point of view of phase transitions and chemical reactions of high-molecular components. It has been found that the polymers under investigation show a good compatibility resulting from the presence of both inter-polymeric covalent bonds and inter-polymeric ionic bridges containing magnesium ions that fulfill the role of chemical compatibilizer. The study has shown that XNBR/CSM blends belong to a group of polymeric materials that are self-extinguished in air. Their flammability, determined by OI and the combustion time in air, clearly depends on the cross-linking degree associated with the quantity of MgO incorporated into the blend of elastomers.

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Abstract

The results of thermal analysis of speciality elastomers CSM with different chlorine and sulphur contents is presented in the article. The thermal curves obtained under the atmosphere of inert gas have been interpreted from the point of view of phase transitions and chemical reactions of the examined polymers during their heating. It has been stated that from among the investigated chlorosulphonated polyethylenes, only CSM24, which has the lowest chlorine content, contains a crystalline phase, clearly influences on its T g temperature. Results of the thermal analysis obtained under inert gas atmosphere have been compared with results obtained under termooxidative atmosphere. Irrespective of the research atmosphere, the thermal decomposition of investigated CSM takes place in three stages. The maximum rate of thermal destruction of modified by heating elastomers, dm/dt, decreases with the increase in chlorine content in the sample having been heated.

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Journal of Thermal Analysis and Calorimetry
Authors:
G. Janowska
,
A. Kucharska-Jastrzabek
,
W. M. Rzymski
, and
A. Pajak

Abstract

The article describes the measurements results of the thermal properties of cross-linked blends of butadiene–acrylonitrile rubber (XNBR, Krynac X.7.50) and chlorosulfonated polyethylene containing different quantity of combined chlorine (CSM24—Hypalon 48, CSM29—Hypalon 20, CSM35—Hypalon 40, and CSM43—Hypalon 30) under inert gas (DSC) and in air (derivatography). The blends were non-conventionally cross linked at a temperature of 150 °C by means of MgO in the presence of stearic acid. The thermal curves obtained were interpreted from the point of view of phase transitions and chemical reactions of the macromolecular components used. It has been found that the elastomers investigated show a good compatibility brought about by the formation of both interpolymeric covalent bonds and interpolymeric and intrapolymeric ionic bridges, which play the role of a chemical compatibilizer. The results of the examinations performed show that the non-conventional cross-linked XNBR/CSM blends prove very good mechanical properties and are self-extinguished in air. Their flammability defined with the value of OI and combustion time in air clearly depends on the type of CSM.

Open access
Journal of Thermal Analysis and Calorimetry
Authors:
M. Prochon
,
G. Janowska
,
A. Przepiorkowska
, and
A. Kucharska-Jastrzabek

Abstract

The article describes the measurements results of the influence of waste keratin on the properties of cross-linked styrene-butadiene rubber especially taking its thermal properties and flammability into consideration. The biopolymer used was thoroughly examined by means of derivatography, elementary analysis, FTIR spectroscopy, Zetasizer nano S90, and Zetasizer 2000. It has been found that the presence of protein facilitates the cross-linking of the elastomer investigated and the elastomeric-protein materials are characterized by good thermal and mechanical properties as well as a considerably increased resistance to thermooxidative aging. Under the influence of keratin, the flammability of the composites obtained is decreased.

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