ANNA BOCZKOWSKA KOMPOZYTY PDF

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Source: Anna Boczkowska .. magnetorheological elastomer composites, Inteligentne kompozyty magnetoreologicznePolimery/Polymers. ANNA BOCZKOWSKA A. BOCZKOWSKA et al. . [3] KONOPKA K., BOCZKOWSKA A., SZAFRAN M., KURZYDŁOWSKI K.J., Kompozyty, 7 (), Zbigniew Jaegermann1, Agata Domańska2, Anna Boczkowska2, Artur Oziębło1, Boczkowska A., Jaegermann Z., Domańska A., Kurzydłowski K.J., Babski K.

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Skip to main content. Log In Sign Up. Microstructure and properties of novel ceramic—polymer composites. Materials Letters 58 — www. Kurzydyowskia a Faculty of Materials Science and Engineering, Warsaw University of Technology, WoloskaWarsaw, Poland b Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, Warsaw, Poland Received 3 February ; received in revised form 12 July ; accepted 17 July Available online 11 September Abstract The present paper describes technology and properties of novel ceramic—polymer construction and functional composites obtained via infiltration of porous SiO2 by polynitrile—urea—urethane elastomer PNUU.

The obtained results show that infiltration method can be used to fabricate composites with percolation of ceramic and polymeric phases. These composites exhibit a high compression strength together with ability to sustain large deformations.

During the cycling loading, the elastomer behaves as strengthened by the ceramic.

Microstructure and properties of novel ceramic–polymer composites | Anna Boczkowska –

On the other hand, the presence of elastomeric phase prevents the composite from rapid failure. Scanning electron microscopy SEM technique was used to describe the composite microstructure and stereological methods for its quantitative description. The elastic modulus and density of composites were measured and discussed in terms of the rule of mixture. D Elsevier B. On the other hand, infiltration of polymers into porous ceramic matrix seems to be relatively a novel Ceramic—polymer composites are a new class of con- idea.

The composites obtained in this way are expected to struction and functional materials of a great potential for exhibit to a large degree rubber-like properties, as shown in industrial applications. If polymer and ceramic form Fig. Kompozuty combinations of properties opens application bkczkowska, for example, as shock absorbing 2. Moreover, these composites retain electrical and chemical properties of ceramic matrix. As a result, piezo- Porous SiO2 samples used in the present study had electric ceramic—polymer composites can be produced for cylindrical shape with a mm diameter and mm height.

The porous nana was obtained by process of sintering of Polymer matrix—ceramic composites are nowadays com- quartz purity The average size of pores, measured by the E-mail address: Sample of elastomer before a and during compression test b.

The density of the sample was equal to 1. Open porosity measured by the Archimedes method carried out using tensile testing machine Instron type The following substrates were used to obtain the polynitrile—urea—urethane elastomer PNUU: An attempt is also made to explain their a. Such segmented urea—urethane elastomer has macromolecules built from soft S and hard The PNUU elastomer was synthesized by one-shot segments Hschematically representable as: All reactions were carried out under 2—5 hPa pressure and in a vacuum reaction vessel equipped with a mechanical stirrer.

Subsequently, the mixture was cast addition reaction of ethylene oligoadipatediol OAE with into special moulds with porous ceramic samples inside, diisocyanate.

The hard segments are obtained in an addition heated to about F5 8C. Next, the infiltration process was reaction of the isocyanate groups —NCO with the chain carried out using the vacuum chamber [10].

Due to the low extender such as low-molecular-weight compound terminat- viscosity of substrates, all pores could be easily filled by the ing with amino groups —NH2 [11,12].

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The polyaddition reaction of obtaining DCDAcommonly known as cyanoguanidine, could be elastomer was conducting in situ inside the pores [10]. The used as a chain extender. By using one-shot technology cast, elastomer was cured for 10—14 h at F5 8C. Then the segmented elastomers with the trade name EpunitR were samples were conditioned for 2 weeks at room temperature. Observations of the microstructure of the composites DCDA contains two amino groups and one highly polar were carried out with the scanning electron microscopy cyanimine group bound to the same carbon atom Fig.

Urea groups chemical structure. As a result of amino and isocyanate group reaction, the polar urea groups are formed Fig. The existence in every short hard segment of strong polar urea group and strong polar nitrilimide side-group influen- ces the urea—urethane properties.

It could also influence the ceramic—elastomer strong interactions. This means that the oxygen index of Fig.

Microstructure of the composites, SEM image. Epunits is on the same level as that of polysulphones and phenol formaldehyde polymers [9]. They are also distin- guished by low water absorption, high resistance to hydrolysis and high resistance for abrasive wear especially leading to the microstructure with percolation of the at the moisture conditions.

The SEM observation of the work at moisture conditions with pH from 3 to 11 for a long fracture surface of the composites proved also a good time. PNUU is also characterized by such advantageous adhesion of the elastomer to the ceramic matrix Fig.

Quantitative analysis of the microstructure of the Hitherto Epunits are used for making a broad kind of composites was carried out using the stereological products, for instance, sieves working mainly for minerals methods [17]. A special software has been used to mining [16]. The molar ratio of hard and soft segments can measure the following parameters: In this elastomeric phase V V and relative surface of the interface work, PNUU with molar ratio of hard to soft segments boundaries ceramic—elastomer S V.

The results are pre- equals 1. The schematic structure of the macro- The density of the composite can be calculated by the molecules of such PNUU can be described as: Some properties of the elastomer are given method.

The calculated density is equal to 1. Results and discussion are infiltrated by the elastomer. It has been observed that under the applied condition the elastomer infiltrated into the pores of ceramic matrix, Table 2 Characteristic properties of elastomer [8,9] Property Value Density 1. As a consequence, the relationships between E C and q C can be Samples before and after compression tests are shown in estimated as follows: The diagrams of stress contraction are presented in Fig.

The SEM observations the mixture Eq. If it is assumed that the composite revealed that the cracks propagating through the ceramics material is composed of two solid materials, SiO2 and are deflected at the elastomer Fig.

Large deformation elastomer, the modulus of solid ceramics should be taken for of the composite and hysteresis loop upon unloading can calculation. It should be noted that this specific present case the, destruction of the ceramic skeletons does modulus value is much higher than the value obtained from not lead to their de-cohesion.

During the compression, the the compression test Table 4.

This is due to using E C value sample assumes a barrel shape Fig. A more realistic after unloading. In general, it is similar to the compression curve obtained for elastomer.

However, the elastic modulus and the values of stresses at a large deformation are higher. The properties of the composite boczkowsk the compression— unloading—compression test suggests that the elastomer behaves as a matrix strengthened by the ceramics. The values of E modulus for ceramics, composite and elastomer calculated from the compression test are presented in Table 4.

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Anna Boczkowska

The E modulus of ceramic—polymer composite after the compression test I is the same as for SiO2. The stiffness of composite decrease after the test II of compression, but still is much higher than the stiffness of elastomer. The elastic modulus of composites examined in the present study E C can be estimated from the rule of the mixture [5] using the following formula: Samples before and after compression test: Diagrams of r—e of samples SiO2, SiO2 with elastomer and elastomer.

In this case, the specific modulus is lower than the value the volume fraction of elastomeric phase were used for obtained from compression test. The density of the composite was calculated by the rule of the mixture and was also measured by Archimedes 5. The values obtained from both methods are nearly the same. The E modulus can also be calculated by the rule Results of the present study show that infiltration method of the mixture; however, the elastic modulus of the can be used to fabricate composites with percolation of elastomer can be neglected.

It has been found that the ceramic and polymeric phases. The density analysis stiffness of the composite does not differ from the stiffness revealed that Also, the SEM observations of q C was compared with the value calculated according to the fracture surface of the composites proved that almost all the rule of the mixture.

The calculations lead to the pores are completely filled by elastomer. SEM investiga- conclusion that the elastic modulus for porous ceramics tions also showed a good adhesion of the elastomer to the should be used in calculation of E C.

The studied composites exhibit high compression Quantitative analysis of the microstructure of the strength together with the ability to sustain large deforma- composites was carried out to estimate the volume fraction tion due to the fact that the elastomer shows the rubber of elastomeric phase and the relative surface of the elasticity and deforms after the ceramics looses its boundaries of elastomer.

The results of measurement of cohesion. The high compression strength of composite is due to crack energy dispersed by the elastomer, because the cracks propagating through the ceramics are deflected at the elastomer area which was confirmed by the SEM observations.

Boczkowska, Anna

During the cycling compression, elastomer behaves as a matrix strengthened by the ceramics; as a consequence, the stiffness of composite is higher than the stiffness of elastomer. Due to the presence of the elastomer, the composite does not undergo sudden failure. Crack propagation in composite, SEM image.

Sleziona, Podstawy Technologii Kompozytow, Wydawnictwo composite. The elastomer behaves as a percolated constit- Politechniki Slaskiej, Gliwice,p.

Leda, Kompozyty polimerowe z wyoknami ciagyymi, Wydaw- nictwo Politechniki Poznanskiej, Poznan,p. Wisniewski, Colloids and Surfaces. A — This work was supported by funding from the Warsaw [9] Dow Chemical, Urethane isocyanates. Batorski, Kompozyt ceramiczno-polimerowy i sposob wytwarzania kompozytu ceramiczno-polimerowego, in voice patent PL no. Markiewicz, Polimery 39 Szafran, Kompozyty 3 Kurzydlowski, [14] Patent PL, ,