Investigation of dielectric properties of bacterial cellulose -thermoset resin nanobiocomposite

Document Type : Complete scientific research article

Authors

Abstract

Abstract
Background and objective: Cellulose is the most abundant polymer on earth and has enormous industrial importance.one of the common applications for native cellulose is using as electrical insulator. The main hurdle of cellulose as application in electrical insulators is porosity and hygroscopicity of paper. Thus to remove humidiy from pores, paper is impregnated by oil or resins. The aim of this research is using of bacteria to produce cellulose and preparation insulator composite and paper from bacterial cellulose. The other purpose is comparison physical properties them with composite and paper produced from kraft pulp.

Material and Methods :The organism used was Gluconacetobacter xylinus (BPR 2004) which was purchased from IROST, Iran. Kraft pulp was prepared from factory of Mazandaran wood and paper. G.xylinus was incubated in a static Hestrin-Schramm culture at 28°c For 30 days. The obtained BC pellicles had 10mm thick.Then, BC pellicles purified and washed by deionized water .The pellicles were cut into small pieces and disintegrated by blender and standard pulp-disintegrator in lab. Aqueous suspension of kraft pulp was prepared. The content of bacterial cellulose that was added to suspension, was as follows: %5, 10 % and 15%. To prepare hand sheets of kraft pulp and kraft pulp- BC was used from hand sheet maker. BC sheets prepared from disintegrated BC by vacuum method. The handsheets were dried in oven then conditioned. Basis weight of hand sheets was considered 60g/m2. Dried handsheets were immersed in phenolic resin (PF). To obtain composites, 5 immersed handsheets from every treatment lay up and hot pressed at 150 °c and 100Mpa for 10min. Then obtained samples conditioned.
Findings:To investigate of physical properties of samples was used from Dp, XRD ,FTIR,FE-SEM tests and also insulation tests composed of Loss tangent,capacitance,dielectric constant and break down voltage was used.The result showed degree of polymerization (Dp) bacterial cellulose was upper than kraft pulp.The result of X-ray diffraction indicated, crystallinity and crystalline size of bacterial cellulose was upper that kraft pulp. Air penetration test in hand sheets demonstrate with increasing bacterial cellulose decrease porosity and the air couldn’t penetrate in handsheet. Kraft paper showed most air penetration and also most porosity. FE-SEM images showed morphology and structure of samples. Findings of FTIR demonstrate interaction between reinforcement and matrix in composites. Dielectric properties was measured as loss tangent, capacitance, dielectric constant and breakdown voltage. The results showed BC and kraft paper had minimum and maximum loss tangent in order and this is conversely in its composite. With increasing of bacterial cellulose from 5-15%, loss tangent increased in hand sheets and its composites. Capacitance and dielectric constant showed similar trend to loss tangent. The breakdown voltage of hand sheets and composites increased with enhancement of bacterial cellulose.

Conclusion:The results showed ,crystallinity, crystal size and degree of polymerization of bacterial cellulose was upper than kraft pulp. Also hand sheets of bacterial cellulose had lower dielectric loss factor, dielectric constant, capacitance.But dielectric break down voltage ofbacterial cellulose handsheets was upper.

Keywords

Main Subjects

References

1.Albu, M.G., Vuluga, Z., Panaitescu, D.M., Vuluga, D.M., Căşărică, A., and Ghiurea, M. 2014.
Morphology and thermal stability of bacterial cellulose/ collagen composites. Central
European Journal of Chemistry 12(9): 968–975. Cent. Eur. J. Chem.
2.Ashori, A., Sheykhnazari, S., Tabarsa, T., Shakeri, A., and Golalipour, M. 2012. Bacterial
cellulose/ silica nanocomposites: Preparation and characterization. Carbohydrate Polymers
90(1): 413–418.
3.Basta, A.H., and El-Saied, H. 2009. Performance of improved bacterial cellulose appli-cation
in the production of functional paper. Applied Microbiology, 107(6): 2098–2107.
4.Bielecki, S., Krystynowiz, A., Czaja, W., and Brown, M. 2006. Microbial cellulose-the natural
power to heal wounds. J. Biomaterials. 27(2): 145-151.
5.Bras, D., Stromme, M., and Mihranyan, A. 2015. Characterization of diellectric propertiesof
nanocellulose from wood and algae for electrical insulator applications. Phys. chem. B. 119:
5911-917.
6.Cakar, F., Kati, A., Ozer, I., Dilan Demir Bag, D., Sahin, F., and Aytekin, A.O. 2014. Newly
developed medium and strategy for bacterial cellulose production. Bio Chemical
Engineering Journal. 92: 35-40.
7.Fang, L., and Catchmark, J.M. 2014. Characterization of water-soluble exopolysaccharides
from Gluconacetobacter xylinus and their impacts on bacterial cellulose crystallization and
ribbon assembly. Cellulose .21: 3965–3978.
8.Gabr, M.H., Elrahman, M.A., Okubo, K., and Fujii, T. 2010. A study on mechanical
properties of bacterial cellulose/epoxy reinforced by plain woven carbon fiber modified with
liquid rubber. Composites part A. 41: 1263-1271.
9.Jeon, S., Yoo, Y.M., Park, J.W., Kim, H.J., and Hyun, J. 2014. Electrical conductivity and
optical transparency of bacterial cellulose based composite by static and agitated methods.
Current Applied Physics. 14: 1621–1624.
10.Juntaro, J., Ummartyotin, S., Sain, M., and Manuspiya, H. 2012. Bacterial cellulose
reinforced polyurethane-based resin nano composites: A study of how ethanol and
processing pressure affect physical, mechanical and dielectric properties. Carbohydrate
polymers. 87: 2464-2469.
11.Mohite, B.V., and Patil, S.V. 2014. Physical, structural, mechanical and thermal
characterization of bacterial cellulose by G. hansenii NCIM 2529. Carbohydrate Polymers.
106: 132–141.
12.Nakagaito, A.N., Iwamoto, S., and Yano, H. 2005. Bacterial cellulose: The ultimate nano –
scalar cellulose morphology for the production of high-strength composites. Materials
science and processing. 80: 93-97.
13.Nogi, M., and Yano, H. 2008. Transparent nano composites based on cellulose produced by
bacteria offer potential Innovation in the electronics device industry. Advanced material. 20:
1849-1852.
14.Poletto, M.P., Zattera, A.J., and Santana, R.M.C. 2012. Structural differences between wood
species: Evidence from chemical composition, FTIR spectroscopy, and thermogravimetric
analysis. Appl. Polym. Sci., 126: E336–E343.
15.Rezaee, A., Solimani, S., and Forozandemogadam, M. 2005. Role of plasmid in production
of Acetobacter xylinum biofilms. Biochemistry and Biotechnology. 1(3): 121-125.
16.Santos, S.M., Carbajo, J.M., Gómez, N., Quintana, E., Ladero, M., Sánchez, A., Chinga-
Carrasco, G., and Villar, J.C. 2016. Use of bacterial cellulose in degraded paper restoration.
Part II: application on real sample. Materials Science, 51: 1553–1561.
17.Sheykhnazari, S., Tabarsa, T., Ashori, A., and Ghanbari, A. 2016. Bacterial cellulose
composites loaded with SiO2 nanoparticles: Dynamic-mechanical and thermal properties.
International Journal of Biological Macromolecules, 93: 672–677.
18.Sheykhnazari, S., Tabarsa, T., Ashori, A.R., Shakeri, A.R., and Golalipour, M. 2011.
Bacterial synthesized cellulose nanofibers; Effects of growth times and culture medium on
the structural characteristics. Carbohydrate polymers. 86: 1187-1191.
19.Thygesen, A., Oddershede, J., Lilholt, H., Thomsen, A.B., and Stahl, K. 2005. On the
determination of crystallinity and cellulose content in plant fibres. Cellulose. 12: 563-576.
20.Trovatti, E., Oliveira, L., Freire, C.S.R., Silvestre, A.J.D., and Pascoal Neto, C. 2010. Novel
bacterial cellulose-acrylic resin nanocomposites. Composites Science and Technology. 70:
1148-1153.
21.Ul-Islam, M., Khan, T., and Park, J.K. 2012. Nanoreinforced bacterial cellulosemontmorllonite
composites for biomedical applications.Carbohydrate polymers. 89: 1189-
1197.
22.Ummartyotin, S., Juntaro, J., Sain, M., and Manuspiya, H. 2012. Development of transparent
bacterial cellulose nano composites films as substrate for flexible organic light emitting
diode (OLED) display. Industrial crops and products. 35: 92-97.
23.Wada, M., Okano, T. 2001. Localization of Iα and Iβ phases in algal cellulose revealed by
acid treatments. Cellulose 8: 183–188.
Journal of Wood and Forest Science and Technology
Volume 24, Issue 2
September 2017
Pages 157-170

Files

Share

How to cite

Statistics