Nanopartikül ilavesinin epoksi esaslı kompozit malzemelerde kürlenme davranışlarına etkisinin incelenmesi
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Dosyalar
Tarih
2023
Yazarlar
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Yayıncı
Düzce Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Yapılan çalışma, epoksi-nano partikül birleşiminin kompozit malzemelerin kürlenme kinetiği ve mekanik özellikleri üzerine etkilerinin değerlendirilmesi amacı ile gerçekleştirilmiştir. Kürlenme kinetiği davranışlarının tespit ve değerlendirilmesinde izotermal diferansiyel tarama kalorimetrisi (DSC) kullanılırken, mekanik özelliklerin belirlenmesi amacı ile çekme, sertlik ve termal iletkenlik deneyleri gerçekleştirilmiştir. Bunlara ek olarak numunelerin kürlenme sonrası bağ yapısının detaylı olarak incelenebilmesi için FTIR testleri yapılmıştır. Çalışmalar, Hexion marka ticari Epıkotetm MGS L285 epoksi içerisine ağırlıkça farklı katkı oranlarında TiO2 (% 0.1-% 0.5-% 1.0), Al2O3 (% 0.75-% 1.25-% 2.0) ve grafen nanoplatelet (GNP) (% 0.25-% 0.75-% 1.0) katılarak yapılmıştır. 90-100-120 °C sıcaklıklarda gerçekleştirilen DSC analizlerine ait sonuçlar MATLAB programında (eğri uydurma aracı kullanılarak) modellenmiş ve grafikleştirilmiştir. Matematiksel modellerin oluşturulmasında epoksi-nano partikül sistemlerinin kürlenmesini en iyi tanımlayan model olan Kamal-Sourour kinetik modeli kullanılmıştır. Elde edilen kinetik parametreleri ve her sisteme ait kürlenme reaksiyonları Arhenius yasalarına göre analiz edilmiştir. Analiz sonuçlarına göre minimum aktivasyon enerjileri Al2O3'te 21.88 kj/mol, TiO2'de 11.12 kj/mol ve GNP'de 9 kj/mol olarak bulunmuş; Kamal modeline en uygun eğrilerin tüm partiküller için 100 °C'de oluştuğu gözlenmiştir. Bir kimyasal reaksiyonun aktivasyon enerjinin düşük olması bu reaksiyonun daha kısa sürede gerçekleşeceğini ifade ettiğinden, %100 kürlenmiş yapıya ulaşmada en anlamlı modelin GNP olacağı düşünülmektedir. İkinci basamak çalışmalarında tespit edilen optimum sıcaklık değerinde (100 °C) her nano partikül siteminin kendi içerisinde en yüksek kürlenme hızına ulaştığı %0.75-1.0-1.25 katkı oranları ortak değer olarak kabul edilerek DSC çalışmaları, çekme, sertlik ve termal iletkenlik analizleri tekrar gerçekleştirilmiştir. En yüksek çekme dayanımına %1.25 Al2O3 katkılı numunelerde ulaşılırken, en yüksek kopma uzamasına %1.0 TiO2 katkılı numunede ulaşılmıştır. Diğer yandan en yüksek sertlik ise % 1.25 Al2O3 katkılı numunede tespit edilmiştir. Saf epoksiye kıyasla çekme dayanımı, kopma uzaması ve sertlikte sırası ile %140.32, % 175, % 7 artış tespit edilmiştir. En yüksek termal iletkenlik değerlerine ise tüm parçacıklar için %1.25 oranında ulaşılmıştır. Termal iletkenlik; referans numune ile karşılaştırıldığında GNP, TiO2 ve Al2O3 katkılı numunelerde sırası ile %123.5, %69 ve %47 artış göstermiştir.
The study was carried out to evaluate the effects of epoxy-nanoparticle combination on the curing kinetics and mechanical properties of composite materials. While isothermal differential scanning calorimetry (DSC) was used to detect and evaluate curing kinetic behaviors, tensile, hardness and thermal conductivity experiments were carried out to determine mechanical properties. In addition, FTIR tests were performed to examine the bond structure of the samples in detail after curing. Studies have shown that TiO2 (%0.1-%0.5-%1.0), Al2O3 (%0.75-%1.25-%2.0) and graphene nanoplatelet (GNP) (0.25%-0.75%) were added to Hexion brand commercial Epikotem MGS L285 epoxy at different weight ratios. It was made by adding %1.0. The results of DSC analyzes performed at temperatures of 90-100-120 °C were modeled and graphed in the MATLAB program (using the curve fitting tool). The Kamal-Sourour kinetic model, which is the model that best describes the curing of epoxy-nanoparticle systems, was used to create mathematical models. The obtained kinetic parameters and the cure reactions of each system were analyzed according to Arhenius laws. According to the analysis results, the minimum activation energies were found to be 21.88 kj/mol in Al2O3, 11.12 kj/mol in TiO2 and 9 kj/mol in GNP; It was observed that the curves best suited to the Kamal model were formed at 100 °C for all particles. Since the lower activation energy of a chemical reaction means that this reaction will occur in a shorter time, it is thought that GNP will be the most meaningful model in reaching a 100% cured structure. At the optimum temperature value (100 °C) determined in the second step studies, DSC studies, tensile, hardness and thermal conductivity analyzes were carried out again, accepting the %0.75-1.0-1.25 contribution rates at which each nanoparticle system reached its highest curing speed as the common value. While the highest tensile strength was achieved in the samples with %1.25 Al2O3 added, the highest elongation at break was reached in the sample with %1.0 TiO2 added. On the other hand, the highest hardness was detected in the sample with %1.25 Al2O3 added. Compared to pure epoxy, an increase of %140.32, %175 and %7 in tensile strength, elongation at break and hardness, respectively, was detected. The highest thermal conductivity values were reached at %1.25 for all particles. Thermal conductivity; Compared to the reference sample, it increased by %123.5, %69 and %47, respectively, in GNP, TiO2 and Al2O3 added samples.
The study was carried out to evaluate the effects of epoxy-nanoparticle combination on the curing kinetics and mechanical properties of composite materials. While isothermal differential scanning calorimetry (DSC) was used to detect and evaluate curing kinetic behaviors, tensile, hardness and thermal conductivity experiments were carried out to determine mechanical properties. In addition, FTIR tests were performed to examine the bond structure of the samples in detail after curing. Studies have shown that TiO2 (%0.1-%0.5-%1.0), Al2O3 (%0.75-%1.25-%2.0) and graphene nanoplatelet (GNP) (0.25%-0.75%) were added to Hexion brand commercial Epikotem MGS L285 epoxy at different weight ratios. It was made by adding %1.0. The results of DSC analyzes performed at temperatures of 90-100-120 °C were modeled and graphed in the MATLAB program (using the curve fitting tool). The Kamal-Sourour kinetic model, which is the model that best describes the curing of epoxy-nanoparticle systems, was used to create mathematical models. The obtained kinetic parameters and the cure reactions of each system were analyzed according to Arhenius laws. According to the analysis results, the minimum activation energies were found to be 21.88 kj/mol in Al2O3, 11.12 kj/mol in TiO2 and 9 kj/mol in GNP; It was observed that the curves best suited to the Kamal model were formed at 100 °C for all particles. Since the lower activation energy of a chemical reaction means that this reaction will occur in a shorter time, it is thought that GNP will be the most meaningful model in reaching a 100% cured structure. At the optimum temperature value (100 °C) determined in the second step studies, DSC studies, tensile, hardness and thermal conductivity analyzes were carried out again, accepting the %0.75-1.0-1.25 contribution rates at which each nanoparticle system reached its highest curing speed as the common value. While the highest tensile strength was achieved in the samples with %1.25 Al2O3 added, the highest elongation at break was reached in the sample with %1.0 TiO2 added. On the other hand, the highest hardness was detected in the sample with %1.25 Al2O3 added. Compared to pure epoxy, an increase of %140.32, %175 and %7 in tensile strength, elongation at break and hardness, respectively, was detected. The highest thermal conductivity values were reached at %1.25 for all particles. Thermal conductivity; Compared to the reference sample, it increased by %123.5, %69 and %47, respectively, in GNP, TiO2 and Al2O3 added samples.
Açıklama
Anahtar Kelimeler
Kimya Mühendisliği, Chemical Engineering, Makine Mühendisliği
