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The formation of adhesion bonds during the creation of two-layer polymer films and coatings capable of acid–base interaction is considered. The coatings are obtained from polymer solutions, and the second layer is formed from the polymer solutions and their mixtures on a hard polymer coating. As a result of absorption by the coating of a considerable amount of solvents (to 14%), polymer macrochains are able to approach one another at a distance necessary for the formation of acid–base (hydrogen) bonds and a transition layer. The polar component of the work of adhesion is equal to about 50% of the whole work W
a. There is no interrelation of the thermodynamic work W
a between the films and the work of their separation into layers. The main part of the external work upon the separation is spent (if strong donor–acceptor bonds are formed) for extracting the segments and macrochains of polymers out of the films. 相似文献
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Lukosiute I. Levinskas R. Sapragonas J. Kviklys A. 《Mechanics of Composite Materials》2004,40(2):151-158
Composite structures consisting of an epoxy resin matrix filled with a porous perlite containing a finely dispersed polyvinyl chloride are investigated. Models of the composites are analyzed in which the formation of a transition layer between the filler particles and the matrix may arise as a result of interaction between the separate components. The influence of the perlite and plasticized polyvinyl chloride particles on epoxy composite characteristics, such as the bending, tensile, impact, and adhesion strengths, are studied. 相似文献
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Aurita Butkevi
it Mindaugas Liaudanskas Darius Kviklys Dalia Gelvonauskien Valdimaras Janulis 《Molecules (Basel, Switzerland)》2020,25(22)
As the interest in heirloom cultivars of apple trees, their fruit, and processed products is growing worldwide, studies of the qualitative and quantitative composition of biological compounds are important for the evaluation of the quality and nutritional properties of the apples. Studies on the variations in the chemical composition of phenolic compounds characterized by a versatile biological effect are important when researching the genetic heritage of the heirloom cultivars in order to increase the cultivation of such cultivars in orchards. A variation in the qualitative and quantitative composition of phenolic compounds was found in apple samples of cultivars included in the Lithuanian collection of genetic resources. By the high-performance liquid chromatography (HPLC) method flavan-3-ols (procyanidin B1, procyanidin B2, procyanidin C2, (+)-catechin and (−)-epicatechin), flavonols (rutin, hyperoside, quercitrin, isoquercitrin, reynoutrin and avicularin), chlorogenic acids and phloridzin were identified and quantified in fruit samples of heirloom apple cultivars grown in Lithuania. The highest sum of the identified phenolic compounds (3.82 ± 0.53 mg/g) was found in apple fruit samples of the ‘Koštelė’ cultivar 相似文献
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A. Kviklys 《Mechanics of Composite Materials》2000,36(2):143-148
An analytical relationship between the thermooxidation rate constants and mechanical properties of composite materials under
isothermal and dynamic conditions is obtained. With the example of epoxy-based composites, it is shown that the kinetic parameters
of thermooxidation can be used to predict the internal stresses and breakdown voltage of coatings. The calculated drop in
the impact toughness exceeds its experimental value by 30%, while the calculated relative breaking elongation is 1.5–2 times
greater than the experimental one. A considerable decrease in these indices is observed at a loss of 0.1–1 wt.% of volatile
products of thermooxidation.
Submitted to the 11th International Conference on Mechanics of Composite Materials (Riga, June 11–15, 2000).
Translated from Mekhanika Kompozitnykh Materialov, Vol. 36, No. 2, pp. 237–248, January–February, 2000. 相似文献
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Based on a plane model of composites, the effect of a transition layer on the elastic modulus Ec of the composites is analyzed in the case where, under the action of a load, the transition layer is formed both on the side
of matrix and filler. In evaluating Ec, it is assumed that the elastic modulus in the layer grows linearly from the elastic modulus of matrix to that of filler,
but pores in the filler are impermeable to matrix macromolecules. Analytic relation ships are found which allow one to determine
the volume fractions of the transition layer on the side of matrix and filler if the experimental elastic modulus of the composite
is known. These relationships are used to find the magnitude of the layer in epoxy composites with various fillers and to
evaluate its effect on the compressive elastic modulus of the composites.
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Translated from Mekhanika Kompozitnykh Materialov, Vol. 42, No. 5, pp. 693–700, September–October, 2006. 相似文献
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