Wyniki wyszukiwania - Biblioteka Nauki

1

Synteza i właściwości sieciujące di(met)akrylanu fenoloftaleiny

100%

Jantas R. , Miller A. , Draczyński Z. , Rutkowski J.

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2001

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tom z. 146

51-54

EN

By reacting esterification of phenolphtalein with (meth)acrylate chloride, di(meth)acrylate phenolphtalein were obtained. Based on FTIR and 1H-NMR spectra the structures of the dimonomers were confirmed. The dimonomers were used as new crosslinkers to crosslink poly(methyl methacrylate). The influence of the kind of dimonomers and amount on the crosslink density and some properties of the crosslinked polymers networks such as swelling and mechanical properties (tensile strength and elongation at break) were examined.

2

Polymerization of methyl methacrylate in the presence of carbon - nanotubes (CNTs)

75%

Szafko J. , Onderko K. , Pabin-Szafko B.

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2001

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tom z. 146

45-49

EN

The verified values of the densities of methyl methacrylate (MMA) and poly(methyl methacrylate) (PMMA) were determined in the temperature range of 20-60 degrees C, which were used to establish the dependence between the contraction of monomer and its conversion (by dilatometric method). Polymerization of MMA initiated by 2,2'-azobis (2-methyl-4-hydroxybutyl propionate) (AIB-BD) in N,N'-dimethylformamide (DMF) was also observed in the presence of three kinds of carbon-nanotubes (CNTs). The interpretation of kinetics of this process was performed according to equation of the first order.

3

Preparation and modification of microspheres by dispersion copolymerization of 3-chloro-2-hydroxypropyl methacrylate and methyl methacrylate

75%

Łukaszczyk J. , Cebulska A.

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2001

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tom z. 146

27-30

EN

Epoxy-functional polymeric microspheres were obtained by the modification of the surface of microspheres based on copolymers of 3-chloro-2-hydroksypropyl methacrylate. Microspheres were prepared by dispersion polymerization. The effect of the type of stabilizer (PVAc or PEO) on the particle size, size distribution and yield was investigated.

4

Postęp w dziedzinie promotorów adhezji elastomerów do metali

63%

Dębski K. , Sajewicz J. , Rajkiewicz M. , Mężyński J.

Elastomery

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2008

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tom T. 12, nr 3

3-9

PL

Wyniki badań wytrzymałości połączeń gumy z metalami z użyciem promotorów adhezji zawierających akrylan cynku i metakrylan cynku wskazują na zasadność ich stosowania. Uzyskano dobrą adhezję gumy do metali. Z tego powodu dalsze prace badawcze będą się skupiać na doborze dodatków modyfikujących oraz ewentualnym zastapieniu akrylanu cynku i metakrylanu cynku akrylanami innych metali. Z dotychczasowych badań wynika potrzeba wytypowania najkorzystniejszego sposobu otrzymywania akrylanów i metakrylanów innych metali (między innymi wapnia i magnezu), a następnie wykonania badań aplikacyjnych uzyskanych z ich udziałem promotorów adhezji. Jest konieczne wykonanie szczegółowych badań analitycznych pozwalających na dokładne określenie składu produktu. Wyniki badań pozwolą na sprecyzowanie, w jakim kierunku należy prowadzić optymalizację procesu otrzymywania soli kwasu akrylowego i/lub metakrylowego.

EN

The results of investigations of rubber-metal joins with use of adhesion promoters based on zinc acrylate and zinc metacrylate showed their validity. Adhesion of rubber to metals is very high. Because of this, future work will be concentrated upon selection of modifying agents and eventually upon acrylates and metacrylates of other metals. On the basis of the previous studies one can say that obtaining of acrylates and metacrylates of other metals (i.a. calcium and magnesium) is necessary and application research of adhesion promoters obtained with them and determination most beneficial composition is also needed. There is also necessity of detailed analytical research which allow to determine composition of the product. Results obtained will show direction, in which optimization of the process of obtaining acrylic acid (and/or metacrylic acid) salts should be conducted.

5

Degree of conversion of dental composite materials in relation to different light-curing parameters

63%

Malara P. , Czech Z. , Świderski W.

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tom Vol. 70, nr 2

60--69

EN

Purpose: The aim of the work was determine conversion degree of composite dental materials with different resins in relation to different light-curing parameters. Design/methodology/approach: The article provides an insight on factors influencing conversion degree of composite materials. Standardized samples made of Herculite XRV based on a methacrylate resin and Filtek Silorane based on silorane resin and were cured using two types of Light Curing Units (LCUs) – halogen and LED. The samples were cured at different distances and for different times. Findings:Research has showed that the polymerization of Filtek Silorane composite is significantly slower than polymerization of Herculite XRV composite. Extending exposure time does not compensate for decrease of light intensity caused by increase of the distance of the light source from the surface of cured composite. Research limitations/implications: Further studies on degree of conversion of dental composite materials will allow to expand the knowledge on characteristics of materials used in dental clinical practice. Practical implications: Evaluation of curing methods, curing parameters and good knowledge on units used in light-curing of composite materials allow to acquire filling materials with best functional qualities. Originality/value: The paper presents degree of conversion of composite materials based on different matrixes and cured with different methods.

6

The effect of the curing time and the distance from the light source on hardness of Methacrylate and Silorane resin-based dental composite materials

63%

Malara P. , Czech Z. , Świderski W.

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tom Vol. 70, nr 1

28--38

EN

Purpose: The aim of the work was to test hardness of composite dental materials with different resins in relation to different light-curing parameters. Design/methodology/approach: The following article provides and insight into factors influencing hardness of composite materials. Standardized samples made of Herculite XRV based on a methacrylate resin and Filtek Silorane based on silorane resin were tested using two types of Light Curing Units (LCUs) – halogen and LED. The distance of light source and time of curing differed between samples. Findings: Filtek Silorane composite compared to Herculite XRV composite guarantees higher hardness, regardless of the used LCU type. Using LED LCU compared to halogen LCU allows to obtain higher hardness both for Herculite XRV and Filtek Silorane composite. The lower the distance of light source the higher the hardness of composite material. Research limitations/implications: Further studies will provide additional information on other properties such as compressive strength, wear resistance and light transmission. Practical implications: This article presents important comparison between older and newer composite technology. It provides practical information on polymerization methods. Originality/value: Article shows broad spectrum of different curing methods, important to the composite use in dentistry.

7

Modyfikacje nienasyconych estrów skrobi aminami i tiolami

51%

Stawski D.

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tom z. 61

45-56

PL

W pracy zsyntezowano estrowe pochodne skrobi (akrylan i metakrylan) metodą międzyfazowej estryfikacji skrobi odpowiednimi chlorkami kwasowymi. Zbadano nieopisaną dotąd w literaturze nukleofilową addycję amin pierwszo- i drugorządowych oraz tioli do grup winylowych akrylanu i metakrylanu skrobi. Określono wpływ temperatury, rodzaju aminy, stopnia podstawienia i rodzaju rozpuszczalnika na kinetykę addycji do akrylanu skrobi. Porównano odporność termiczną skrobi, jej pochodnej estrowej i aminowej. Wykazano działanie antyelektrostatyczne oraz sorpcyjne trzeciorzędowych i czwartorzędowych pochodnych skrobi.

EN

Ester derivatives of starch, which contain reactive vinyl bonds, such as starch acrylate and methacrylate, were synthesized. The synthesis of these compounds, which had not been sufficiently described as yet, was carried out at a low temperature (about -7°C) by the interfacial esterification of starch with appropriate acid chlorides. Under these conditions no degradation of the polysaccharides chain and no side reactions of vinyl bonds take place. Based on the results of elementary analysis and FTIR, H-NMR and C-NMR spectra, the chemical composition of the esterification products has been confirmed. The second stage of this study was intended for detailed investigation of the so far unreported reactions of nucleophilic addition of primary and secondary amines and dodecanitiole to vinyl groups of starch acrylate and methacrylate under the conditions of pseudo-first order reaction. Based on the obtained results it has been found that the effect of temperature on the reaction rate is consistent with the general assumption of chemical kinetics. The calculated activation energies for the secondary amine addition ranged from 13.2 to 24.2 kJ/mol and those for primary amines from 11.7 to 13.0 kJ/mol. A slight effect of THF and dioxane on the addition kinetics was also observed, while the reaction course was slower in DMSO, which is characterized by a considerably higher dielectric constant. On the other hand, a clear decrease in the constants of pseudo-first order reaction rates was observed in the case of primary and secondary amines with different lengths of aliphatic chain. The presence of amine and thiol groups in the products of addition was confirmed by the methods of FTIR, H-NMR and C-NMR. On the basis of the results of thermogravimetric analysis of starch and products of its modification it has been found that the thermal resistance of starch acrylate is slightly higher than that of initial starch and the degree of substitution with ester groups exerts no significant influence on their thermal stability. The starch derivatives containing tertiary amine groups and anionic groups were successfully used as an antistatic finish for polyester fabrics. The use of N,N-dipropylaminepropionate of starch as a sorbent of copper ions has been also investigated. The results obtained show that the amine derivatives of starch can combine about 1.5 mmole of Cu2+/g sorbent after 10 h.