Tag Archives: plastics

Chemistry and pharmacy closer to nature. How to prolong healthy life with natural compounds?

Chemistry and pharmacy closer to nature. How to prolong healthy life with natural compounds?

Iwona WAWER ? Medical University of Warsaw, Faculty of Pharmaceutical, Department of Physical Chemistry, Warsaw Please cited as: CHEMIK 2010, 64, 4, 219-227 Modern medicine (especially personalised and nutritional approach) focuses more attention on the diet, life style and the environment. Scientists have to examine more closely what we are eating, how diseases can be treated more rationally, and how we can more effectively use our natural resources. The pharmaceutical industry is searching for new medical plants, the functional compounds of which can serve as a starting point for the development of new drugs. Health-beneficial and life-prolonging effects of polyphenols are accompanied by the stimulation of various maintenance mechanisms, including protection against free-radical and oxidation- induced damage. These natural compounds are promising anti-inflammatory, antiviral, antibacterial and anticancer agents. The representatives of polyphenols: resveratrol, epigallocatechin-gallate, curcumin, proanthocyanidin, chlorogenic acid and rosemarinic acid, betalain, anthocyans are characterised as potential candidates for drugs. This review provides some information and serves to encourage work (chemical synthesis) in...
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The impact of external factors on the degradation process of refinish top coatings

The impact of external factors on the degradation process of refinish top coatings KURCOK M., LACHOWSKI A., ŚLIWA A. Please cite as: CHEMIK 2012, 66, 4, 315-320 This paper presents the studies on the impact of factors, to which the top coatings of the motor vehicle body are exposed, on the degradation of such coatings. Two types of the refinish acrylic top coatings were selected for the experimental purpose ? twolayer and three-layer ones. These coatings were exposed to the UV radiation, acid rain and brine. During the exposure period, the samples were successively collected to investigate the degradation level of the material. Keywords: acrylic coatings, UV ageing, acid rain, brine, DMA, porosimetry Read more: pdf-icon...
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Impact of selected chemical substances on the degradation of the polyolefin materials

Impact of selected chemical substances on the degradation of the polyolefin materials CZOP M., BIEGAŃSKA J. Please cite as: CHEMIK 2012, 66, 4, 307-314 An increased production and consumption of various types of plastics leads to the increase of the wastes. The majority of wastes are formed by wastes from polyolefin group. Due to lack of susceptibility to hydrolysis or decomposition, utilization of the plastic wastes is a very complicated problem. Increasing amount of plastic wastes forces a search for the new, ecological and safe methods of waste management. Nowadays, plastics are considered to be main pollution of the natural environment. However, modified plastics can constitute a valuable production material. Recycling of waste polymers is one of the far-reaching methods of their utilization and at the same time limits the consumption of the natural resources. When having contacts with gases, liquids and solids, chemical substances may penetrate into the plastic or wash out various components from them. Resistance of plastics to the impact of chemical substances is called chemical resistance or susceptibility. Impact of chemical substances on plastics...
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Fire-safe polyurethanes modified with new antipyrene

Fire-safe polyurethanes modified with new antipyrene PACIOREK-SADOWSKA J., CZUPRYŃSKI B., LISZOWSKA J. Please cite as: CHEMIK 2012, 66, 4, 297-306 Results of multi-directional investigations on flammability conducted in the framework of studies on new antipyrenes for production of rigid polyurethane-polyisocyanurate (PURPIR) foams were presented in the paper. During determining a new foam recipe, special attention was paid to the possibility of reducing flammability of rigid foams by application of new halogen-free flame retardants. The new boronitrogen compound allowed us to obtain fire-safe PUR-PIR foams characterized by higher oxygen index and retention values in comparison with unmodified foam. Keywords: rigid polyurethane-polyisocyanurate foams, polyols, flammability of foams Read more: pdf-icon...
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Organic semiconductors ? materials of the future?

Organic semiconductors ? materials of the future? ŚWIST A., SOŁODUCHO J. Please cite as: CHEMIK 2012, 66, 4, 289-296 The discovery of electrical conductivity and interesting optical properties (luminescence) of macromolecules with conjugated ?-bond system has revolutionized the electronics. Extensive application of organic semiconductors (organic photovoltaic cells, biosensors, organic light emitting diodes, printed circuits) caused that they being named ?the materials of the future?. In the article was carried out the discussion whether actually conducting macromolecular compounds deserve such a term and will dominate native markets. Keywords: organic semiconductors, electronic market, OLEDs Read more: pdf-icon...
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Methods of synthesis of oligoetherols suitable for obtaining of some polymers with higher thermal stability

LUBCZAK J. Please cite as: CHEMIK 2012, 66, 4, 279-288 Methods of preparation of the oligoetherols containing azacyclic rings are presented. A procedure of hydoxyalkylation of melamine, isocyanuric, uric and barbituric acids with oxiranes, formaldehyde and alkylene carbonates are described. The heterocyclic rings provide the polymeric materials obtained from them with enhanced thermal stability like polyurethanes, polyesters and polyacrylates. The procedures, catalysts, and solvents are described and main directions and possibilities of applications of the compounds are discussed. Keywords: azacyclic compounds, oxiranes, formaldehyde, alkylene carbonates, hydroxyalkylation Read more: pdf-icon...
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State of the industry of plastics processing, elastomers, rubbers and protective coatings in Poland KUBICA S.

Abstract: Information presented in the article is based on the data published by Ministry of Economy, Central Statistical Office, Stock Exchange, technical journals: ?Chemik? (Chemist), ?Materiały Budowlane? Building Materials), ?Elastomery? (Elastomers) covering the state of the industry of plastics processing, elastomers, rubbers and protective coatings in Poland from the period of the second half of revious decade till the first half of the year 2012. Presented analysis covered the state and the trends regarding chosen products of chemical industry, economical position of enterprises, their rofitability, employment, average gross minimum wages, investment expenditures, foreign trade and stock quotes of selected companies. There were also described the current changes published by a daily ?Rzeczpospolita? ? in the ?Lists of 2000 and 500? of the biggest companies from Central and Eastern Europe and by a weekly ?Polityka? in the ?List of 500?. Basing on presented results, the attempt of estimation of the state of the industry of plastics processing, elastomers, rubbers and protective coatings in...
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