بهبود چقرمگی شکست نانوکامپوزیت اپوکسی با استفاده هم‌زمان از نانوذرات سیلیکا با اندازه‌های مختلف

نوع مقاله : پژوهشی

نویسندگان

تهران، دانشگاه صنعتی مالک اشتر، پژوهشکده مهندسی کامپوزیت، صندوق پستی 1774-15875

چکیده

برای افزایش چقرمگی شکست کامپوزیت اپوکسی، رزین اپوکسی و سخت‌کننده انیدریدی با نانوذرات سیلیکا تقویت شد. ذرات سیلیکا با اندازه‌های 12، 20 و 40 نانومتر به شکل تنها یا ترکیب دوتایی به رزین اضافه شده و با دستگاه فراصوتی در ماتریس اپوکسی پخش شدند. تصاویر میکروسکوپ الکترونی نشان داد، پخش ذرات به‌خوبی انجام شده است. نتایج آزمون کشش، افزایش مدول یانگ و استحکام کششی کامپوزیت‌ها را با افزایش کسر وزنی ذرات تقویت‌کننده یا کاهش اندازه آن‌ها نشان داد. استفاده هم‌زمان از دو نوع ذره سیلیکا با اندازه‌های مختلف 20 و 40 نانومتر موجب ارتقای بهتر مدول یانگ و استحکام شد. اما، استفاده از ترکیب هر یک از آن‌ها با اندازه ذرات 12 نانومتر افزایش چشمگیری را در خواص کششی موجب نشد. در حالی که نتایج آزمون خمش سه‌نقطه‌ای نمونه برش‌دار، که برای اندازه‌گیری انرژی شکست انجام شد، اثر هم‌افزایی قابل توجهی را در استفاده هم‌زمان از دو نوع نانوذره سیلیکا نشان داد. انرژی شکست اپوکسی بدون نانوذرات از 280J/m2، برای کامپوزیت دارای نانوذرات  12 نانومتر تا 740J/m2 افزایش داشت. اگر این ذرات به همراه ذرات 20 نانومتر استفاده شوند، با کسر وزنی کل برابر، انرژی شکست تا 770J/m2 زیاد می‌شود. در نهایت محاسبات نشان داد، اندازه دهانه ترک حدود چند میکرومتر بوده که خیلی بزرگ‌تر از ابعاد ذرات سیلیکاست. بنابراین، نقش سازوکار‌های اتصال ترک و انحراف ترک در افزایش چقرمگی ناچیز است و تغییرشکل پلاستیک و گسترش حباب سازوکار‌‌های غالب هستند.

کلیدواژه‌ها

عنوان مقاله [English]

Improving Fracture Toughness of Epoxy Nanocomposites by Silica Nanoparticles

نویسندگان [English]

  • Seyed Reza Akherati Sany
  • Mehrzad Mortezaei
  • Iraj Amiri Amraei
Composite Engineering Research Center, Malek-e-Ashtar University of Technology, P.O. Box: 15875-1774, Tehran, Iran
چکیده [English]

An epoxy resin was modified by silica nanoparticles and cured with an anhydride. The particles with different batches of 12, 20, and 40 nm sizes were each distributed into the epoxy resin ultrasonically. Electron microscopy images showed that the silica particles were well dispersed throughout the resin. Tensile test results showed that Young’s modulus and tensile strength increased with the volume fraction and surface area of the silica particles. The simultaneous use of two average sizes of 20 and 40 nm diameter silica particles still increased these mechanical properties but other combinations of silica particles were unsuccessful. A three-point bending test on each pre-cracked specimen was performed to measure the mode I fracture toughness energy. The fracture energy increased from 283 J/m2 for the unmodified epoxy to about 740 J/m2 for the epoxy with 4.5 wt% of 12 nm diameter silica nanoparticles. The fracture energy of smaller particles was greater because of their higher surface to volume ratio. The fracture energy results showed also that the combined nanoparticles has a synergic effect on the fracture toughness of nanocomposites. Simultaneous use of 10 and 20 nm particles increased the fracture energy to about 770 J/m2. Finally, crack-opening displacement was calculated and found to be in the range of several micrometers which was much larger than the sizes of particles studied. Thus, the toughening mechanisms of crack pinning and crack deflection have a negligible effect on improvement of toughness, nevertheless, the plastic deformation and plastic void growth are dominant mechanisms in epoxy toughening by nanoparticles.

کلیدواژه‌ها [English]

  • epoxy
  • silica nanoparticles
  • fracture toughness
  • toughening mechanisms
  • specific surface area

مراجع

1.Sprenger S., Epoxy Resins Modified with Elastomers and Surface-Modified Silica Nanoparticles, Polymer, 54, 4790-4797, 2013.
2.Xu S.A., Wang G.T., and Mai Y.W., Effect of Hybridization of Liquid Rubber and Nanosilica Particles on the Morphology, Mechanical Properties, and Fracture Toughness of Epoxy Composites, J. Mater. Sci., 48, 3546-3556, 2013.
3.Dai J.B., Kuan H.C., Du X.H., Dai S.C., and Ma J., Development of a Novel Toughener for Epoxy Resins, Polym. Int., 58, 838-845, 2009.
4.Hsieh T., Kinloch A.J.,  Taylor A.C., and Kinloch I.A., The Effect of Silica Nanoparticles and Carbon Nanotubes on the Toughness of a Thermosetting Epoxy Polymer, J. Appl. Polym. Sci., 119, 2135-2142, 2011.
5.Tang L.C., Wan Y., Peng K., Peia Y., Wua L., Chen L., Shu L., Jiang J., and Lai G., Fracture Toughness and Electrical Conductivity of Epoxy Composites Filled with Carbon Nanotubes and Spherical Particles, Compos., Part A: Appl. Sci. Manufact., 45, 95-101, 2013.
6.Tang L.C., Wang X., Wan Y., and Lai G., Mechanical Properties and Fracture Behaviors of Epoxy Composites with Multi-Scale Rubber Particles, Mater. Chem. Phys., 141, 333-342, 2013.
7.Ratna D. and Banthia A.K., Rubber Toughened Epoxy, Macromol. Res., 12, 11-21, 2004.
8.Bagheri R., Takiha Maarouf B., and Motevalian A., Effect of Synergism on Fracture Toughness of an Epoxy-Based Blend Containing Recycled Rubber Particles, J. Polym. Sci. Technol., 17, 267-272, 2005.
9.Feng Q., Yang J., Liu Y., Xiao H., and Fu S., Simultaneously Enhanced Cryogenic Tensile Strength, Ductility and Impact Resistance of Epoxy Resins by Polyethylene Glycol, J. Mater. Sci. Technol., 30, 90-96, 2014.
10.Zavareh S. and Samandari G., Polyethylene Glycol as an Epoxy Modifier with Extremely High Toughening Effect: Formation of Nanoblend Morphology, Polym. Eng. Sci., 54, 1833-1838, 2014.
11.Wetzel B., Haupert F., and Friedich K., Epoxy Nanocomposites Fracture and Toughening Mechanisms, Eng. Fract. Mech., 64, 2376-2398, 2006.
12.Kinloch A., Mohammed R., Taylor A., Eger C., Sprenger S., and Egan D., The Effect of Silica Nanoparticles and Rubber Particles on the Toughness of Multiphase Thermosetting Epoxy Polymers, J. Mater. Sci., 40, 5083-5086, 2005.
13.Salehi H.R. and Salehi M., Synthesis and Mechanical Properties Investigation of Nano TiO2/Glass/Epoxy Hybrid Nanocomposite, J. Polym. Sci. Technol. (Persian), 28, 345-352., 1394
14.Zamanian M., Mortezaei M., Salehnia B., and Jam J., Fracture Toughness of Epoxy Polymer Modified with Nanosilica Particles: Particle Size Effect, Eng. Fract. Mech., 97, 193-206, 2013.
15.Liang Y. and Pearson R., Toughening Mechanisms in Epoxy-Silica Nanocomposites (ESNs), Polymer, 50, 4895-4905, 2009.
16.Dittanet P. and Pearson R., Effect of Silica Nanoparticle Size on Toughening Mechanisms of Filled Epoxy, Polymer, 53, 1890-1905, 2012.
17.Johnsen B., Mohammed K.A., and Taylor A., Toughening Mechanisms of Nanoparticle-modified Epoxy Polymers, Polymer, 35, 530-541., 2007
18.Mahrholz T., Stängle J., and Sinapius M., Quantitation of the Reinforcement Effect of Silica Nanoparticles in Epoxy Resins Used in Liquid Composite Moulding Processes, Composites Part A: Appl. Sci. Manufact., 40, 235-243, 2009.
19.Hsieh T., Kinloch A.J., Masania K., Lee S., Taylor A., and Sprenger S., The Toughness of Epoxy Polymers and Fibre Composites Modified with Rubber Microparticles and Silica Nanoparticles, J. Mater. Sci., 45, 1193-1210, 2010.
20.Hsieh T., Kinloch A.J., Masania K., Taylor A., and Sprenger S., The Mechanisms and Mechanics of the Toughening of Epoxy Polymers Modified with Silica Nanoparticles, Polymer, 51, 6284-6294, 2010.
21.Zappalorto M., Pontefisso A., Fabrizi A., and Quaresimin M., Mechanical Behaviour of Epoxy/Silica Nanocomposites: Experiments and Modelling, Compos., Part A: Appl. Sci. Manuf., 72, 58-64, 2015.
22.Zappalorto M., Salviato M., and Quaresimin M., A Multiscale Model to Describe Nanocomposite Fracture Toughness Enhancement by the Plastic Yielding of Nanovoids, Compos., Part A: Appl. Sci. Manuf., 72, 1683-1691, 2012.
23.Dittanet P. and Pearson R.A., Effect of Bimodal Particle Size Distributions on the Toughening Mechanisms in Silica Nanoparticle Filled Epoxy Resin, Polymer, 54, 1832-1845,2013.
24.Ma J., Mo M., Du X., Rosso P., Freidrich K., and Kuan H., Effect of Inorganic Nanoparticles on Mechanical Property, Fracture Toughness and Toughening Mechanism of Two Epoxy Systems, Polymer, 49, 3510-3523, 2008.
25.Johnsen B., Kinloch A., Mohammed R., Taylor A., Eger C., and Sprenger S., Toughening Mechanisms of Nanoparticle-modified Epoxy Polymers, Polymer, 48, 530-547, 2007.
26.Ou C.F. and Shiu M.C., Epoxy Composites Reinforced by Different Size Silica Nanoparticles, J. Appl. Polym. Sci., 115, 2648-2653, 2010.
27.Zheng Y., Chonug K., Wang G., Wel P., and Jiang P., Epoxy/Nano‐Silica Composites: Curing Kinetics, Glass Transition Temperatures, Dielectric, and Thermal-Mechanical Performances, J. Appl. Polym. Sci., 111, 917-927, 2009.
28.Luo Z., Cai X., Hong R., Wang L., and Feng W., Preparation of Silica Nanoparticles Using Silicon Tetrachloride for Reinforcement of PU, Chem. Eng. J., 187, 357-366, 2012.
29.Faber K. and Evans A., Crack Deflection Processes-I. Theory, Acta Metallurgica, 31, 565-576, 1983.
30.Faber K. and Evans A., Crack Deflection Processes-II. Experiment, Acta Metallurgica, 31, 577-584, 1983.
31.Zhang H., Tang L., Zhang Z., Friedrich K., and Sprenger S., Fracture Behaviours of In Situ Silica Nanoparticle-Filled Epoxy at Different Temperatures, Polymer, 49, 3816-3825, 2008.
32.Lange F., The Interaction of a Crack Front with a Second-Phase Dispersion, Philos. Mag., 22, 0983-0992, 1970.
33.Evans A., The Strength of Brittle Materials Containing Second Phase Dispersions, Philos. Mag., 26, 1327-1344, 1972.
34.Green D.J., Nicholson P.S., and Embury J.D., Fracture of a Brittle Particulate Composite, J. Mater. Sci., 14, 1413-1420, 1979.
35.Liang Y. and Pearson R., The Toughening Mechanism in Hybrid Epoxy-Silica-Rubber Nanocomposites (HESRNs), Polymer, 51, 4880-4890, 2010.
36.Huang Y. and Kinloch A., Modelling of the Toughening Mechanisms in Rubber-Modified Epoxy Polymers, J. Mater. Sci., 27, 2753-2762, 1992.
 
مجله علوم و تکنولوژی پلیمر
دوره 30، شماره 1 - شماره پیاپی 147
فروردین و اردیبهشت 1396
صفحه 3-17

فایل ها

هم رسانی

ارجاع به این مقاله

آمار