Photonic crystals in biology - NanoTR-VI

Poster Session, Thursday, June 17Theme F686 - N1123Hexagonal Boron Nitride (h-BN)/Polyimide Hybrid FilmsCanan Kızılkaya * , Yusuf Mülazim, M.Vezir Kahraman, Nilhan Kayaman Apohan, Atilla GüngörMarmara University, Department of Chemistry 34722 Istanbul/TurkeyAbstract - Polyimide (PI)/hexagonal boron nitride (h-BN) hybrid materials were prepared from a polyimide precursorand functionalized h-BN with a silane coupling agent by thermal imidization technique. Their surface morphologies,structures and thermal performances were determined. The thermal characteristics of PI/ h-BN hybrid films were foundto be better than the polyimide without h-BN.Aromatic polyimide films have aroused a great deal ofinterest as one of the attractive precursors for producingcarbon and graphite films in recent years. Compared withmost organic polymeric materials, PI exhibits superiorthermal stability and mechanical strength. Therefore, alarge number of PI compositions have been extensivelyinvestigated and most of them are well-suited for use asmatrix resins, adhesives, and coatings for highperformanceapplications in the aerospace, electric, andmicro-electronic industries [1,2].Boron nitride is a ceramic material that is isoelectronicwith carbon. Much like carbon, it exists in multipleallotropic forms. The most common structure of boronnitride is the hexagonal form (h-BN). Hexagonal boronnitride has a graphite-like structure with strong bondingwithin the planar, fused, six-membered rings and weak vander waals bonding in-between layers. Along the c-axis forh-BN, boron and nitrogen atoms are stacked above eachother in alternating layers [ 3]. Because of its properties, ithas found uses in heat conductivity applications, electricalinsulation applications, corrosion resistance applications,lubrication applications, personal care applications, and asa plastic additive [4].In the present study, Polyimide (PI)/hexagonal boronnitride (h-BN) hybrid materials were prepared from apolyamic acid as a polyimide precursor and modified h-BN with a silane coupling agent. Aminoalkoxysilane isone of the most widely adopted silane coupling agents forthe modification of various oxide surfaces. This agent,uses for surface treatment of the filler to improve theaffinity between filler and matrix, thereby significantlyincreasing the thermal properties of the composite. Insilane acts as a bridge to connect the ceramic filler and thepolymer matrix together, because it has two differentchemical structures at the two ends of the molecule. Themorphological, mechanical, and thermal properties of thepolyimide hybrid films with different h-BN content werecharacterized.In conclusion, h-BN containing PI hybrid materials wereprepared. ATR-FTIR study indicates that the inorganicnetwork had formed during imidization. Themorphological study proved that the h-BN particles in thepolyimide matrix is dispersed homogeneously. Thethermal stability of the hybrid materials improved with theincreasing amount of h-BN in the compositions. TheLimiting Oxygen Index results increased from 32.0 to42.6. The h-BN containing hybrid materials show fireresistance than the pure polyimide. The mechanicalproperties show that the polyimides/h-BN hybrid materialsare hard and brittle compared with pure polyimide. Thesolvent and chemical resistance experiments for allmaterials show good performance.Figure 1: SEM Micrographs of PI/h-BN 0.5*Corresponding author: ckizilkaya@gmail.com[1] C.Kızılkaya ,S. Karataş , N. K. Apohan , A. Güngör, Journalof Applied Polymer Science, 115, 3256-3264, (2010).[2] S Karatas, N.K. Apohan, H. Demirer, A. Gungor Polym.Adv. Technol., 18,490–496 (2007)[3] M.T. Huang, H. Ishida, Surf. Interface Anal.,37, 621–627(2005).[4] J. Eichler, C. Lesniak, J European Ceramic Society, 28,1105–1109, ( 2008)..6th Nanoscience and Nanotechnology Conference, zmir, 2010 706