Papers - Archive

Nr 3/2015 - Abstracts

Elastomery nr 3/2015 cover

Iwona Pawelec, Sandra Paszkiewicz, Anna Szymczyk, Zbigniew Rosłaniec

Novel elastomers for biomedical applications

This manuscript comprises a review paper on the novel elastomeric materials which can be used in medicine applications. The presented here elastomeric materials were poly(urethanes) and poly(sebacic glycerol) and its copolymers. Herein, the synthesis parameters and properties of new materials have been described. Special attention has been paid on the biocompatibility of those materials to human tissues, as well as the mechanical properties and biodegradability. In addition, the above mentioned materials were partially or entirely obtained from renewable raw materials (sebacic acid, succinic acid, glycerol, poly(caprolactone)).

Monika Auguścik, Joanna Ryszkowska

Porous polyurethane ureas for use as a substrate for tissue engineering produced via solvent-free method

Biodegradable polyurethane ureas for use as substrates for bone tissue were studied. The test materials were prepared by using a prepolymer with water as a macromolecule extender. NaCl and CO2 were used as a porogen. The applied solvent-free method for the preparation of substrates makes it possible to obtain substrates of large size and a suitable pore structure. Substrate materials were prepared from three types of isocyanates, namely one aliphatic and two cycloaliphatic. The use of various isocyanates afforded the materials with different structures and properties. The highest rigidity was demonstrated by polyurethane ureas of isophorone diisocyanate. These materials contain the largest amount of crystalline phase. Aliphatic isocyanate substrates are characterized by the lowest toxicity. All materials are bioactive.

Maciej Sienkiewicz, Malwina Wawrowska, Karolina Wiecierzycka, Helena Janik

Methods of chemical modification of the surface of rubber granulate and rubber goods which are improving their adhesion to polyurethane

Weak physical and chemical interactions of polar polyurethane matrices and nonpolar rubber granulate in polyurethane-rubber composites cause a reduction in mechanical properties, while increasing content of rubber granulate. This problem can be solved by modifying the surface of the grains of rubber granulate, by various types of chemical reaction and physical processes. Chemical methods of activating the surface of grain rubber granulate consist of the modification using various kinds of organic and inorganic compounds or implementation of polar compounds on its surface molecules. This allows to incorporate into the rubber surface chemical reactive groups towards isocyanate groups which are present in the raw materials used in the synthesis of polyurethanes and, consequently, an increase of physical and chemical interactions between particles of rubber granulate, and the polyurethane matrix. This significantly affects improvement of the mechanical properties of polyurethane rubber composite and extends their possible applications. This article was described methods of chemical modification of recycled rubber obtained in the process of grinding waste car tires and elastomers obtained from styrene-butadiene rubber (SBR) and thermoplastic block copolymer styrene-butadiene-styrene (SBS), using sulfuric acid, chlorine gas, trichloroisocyanuric acid (TCCA), sodium dichlorocyanuric acid (NaDCC), silane, and glycidyl methacrylate (GMA) or methacrylic acid (MAA). It is clearly shown that the methods of chemical modification of rubber granulate significantly improves the adhesion to polyurethane.

Jakub Czakaj, Maria Rajkiewicz

The use of rubber butyl reclaim in masterbatches for sealant production

Semi-vulcanized masterbatches of butyl rubber (IIR) and butyl reclaim were mixed with plasticizer and crosslinking resin. The degree of vulcanization is regulated by the content of crosslinking resin. The masterbatches were used for production of thermoplastic sealants, which had good dimensional stability and low slump. Current work investigates the dependency of sealant properties on the content of IIR replaced with butyl reclaim in the masterbatches.

I.A. Mikhaylov, Yu.O. Andriasyan, G.E. Zaikov and A.A. Popov

Investigation of structure and thermophysical characteristics of chlorinated ethylene-propylene-diene rubber (EPDM)

Macromolecular structure of chlorinated ethylene-propylene-diene rubbers (CEPDM) and there probable changes, which happen in process of rubber vulcanization were studied by method of infrared spectroscopy. Rubbers CEPDM-2, CEPDM-4 and CEPDM-16, consequently containing 2, 4 and 16% (mole) chlorine were taken for the investigation. As sample for comparison was used initial ethylene-propylene-diene rubber EPDM, not containing halogen. To determine thermostability of macromolecular structures of investigated polymers under vulcanization temperature, the specimens of rubber subjected to heating vulcanizing press under temperature 151°C during 5, 10, 20, 30, 40, 50 and 60 minutes.
To study thermophysical characteristics of chlorine-containing EPDM were used methods of differential thermal analysis (DTA) and thermo-gravimetric analysis (TGA). In result of spectral investigation of specimens were established that in process of obtaining CEPDM-2, chlorine combine with fragment of ethylidenenorbornene (ENB), but the structure of the main chain wasn't touched. As a result of elimination of hydrochloride new double linkage is forming and halogen in -position to this linkage, that increases vulcanization rate of CEPDM-2 based rubber. When obtaining CEPDM-4 and CEPDM-16 chlorine associated as to ENB fragment as well as to the main chain of polymer, in the result of elimination of hydrochloride another double linkages can occur. This process permanently will result in decrease of ozone resistance of vulcanized rubbers CEPDM-4 and CEPDM-16.

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