Effect of organic modification of layered double hydroxide
Effect of organic modification of layered double hydroxide (LDH) in Polyamide 6/Perkalite™ (PA 6/LDH) nanocomposites FUCULTY RESEARCH DAY, 7 September 2012 Mr. R. Zwane, Prof. R. Sadiku, Prof. S. Ray & Dr. N. Luruli
Outline Ø Introduction Ø Materials Ø Experimental Ø Results and discussion Ø Conclusions Ø Recommendations Ø Acknowledgements Polyamide 6/Perkalite™ (PA 6/LDH) nanocomposites FUCULTY RESEARCH DAY, 7 September 2012 ©
Introduction Ø Introduction of plastic parts in the automotive engines gave several advantages: • • • Light weight Part integration Design flexibility Systems cost saving Improved mechanical performance Ø These contribute to lighter weight vehicles, improved fuel consumption and reduced CO 2 emissions. VS. Ø PA 6/GF composites have been used extensively in under-the-hood applications in the recent past. • • Higher burst pressure on weld-lines Better long-term temperature stability Polyamide 6/Perkalite™ (PA 6/LDH) nanocomposites FUCULTY RESEARCH DAY, 7 September 2012 ©
Introduction continued… Ø The main challenge in glass-filled PA 6 is processing. § Complicated mold designs § Fiber breakage (smaller aspect ratio) § Weaker parts Ø Clay nanoparticles have been shown to improved the properties of PA 6 drastically. § Heat resistance § Gas permeation § Mechanical and tensile properties, etc. Ø Most of the work has been done on montmorillonite (MMT) types of clay. § E. g. 80 C increase in heat distortion temperature, etc. Ø This work focuses on layered double hydroxide (LDH) clay. Polyamide 6/Perkalite™ (PA 6/LDH) nanocomposites FUCULTY RESEARCH DAY, 7 September 2012 ©
Materials Polyamide 6/Perkalite™ (PA 6/LDH) nanocomposites FUCULTY RESEARCH DAY, 7 September 2012 ©
Experimental Sample preparation • • Polymer pulverized to particle size below 1 mm. Physical mixing of powders. Melt mixing in a 30 g co-rotating mixing head. Extrudates chopped to pellets (3 – 5 mm) and then pressed to different shapes. Characterisation • Clays (BET, TEM, SEM, XRD, TGA and FTIR) • Composites (DSC, TGA, DMA, XRD and FTIR) Mechanical Testing • Tensile testing Polyamide 6/Perkalite™ (PA 6/LDH) nanocomposites FUCULTY RESEARCH DAY, 7 September 2012 ©
Results and Discussions (Clays) BET TEM cont. TEM Micrograph of Perkalite™ FR 100 TEM Micrograph of Perkalite™ LD
Results and Discussions (Clays cont. ) SEM Micrograph of Perkalite™ FR 100 SEM Micrograph of Perkalite™ LD
Results and Discussion (Clays cont. ) TGA FTIR Polyamide 6/Perkalite™ (PA 6/LDH) nanocomposites FUCULTY RESEARCH DAY, 7 September 2012 ©
Results and Discussion (Composites) Onset Temperature of Crystallisation(�C) DSC LDH % � Perkalite LD Time (min. ) � Perkalite FR 100 Filler loading � Polyamide 6/Perkalite™ (PA 6/LDH) nanocomposites FUCULTY RESEARCH DAY, 7 September 2012 ©
Results and Discussion (Composites cont. ) Ash residue (%m/m) � Onset Temp. of Decomp. (�C) � TGA Filler loading (%m/m) � Perkalite FR 100 • • Perkalite LD Filler loading (%m/m) � Perkalite FR 100 Perkalite LD FR 100 - Max. 12% decrease LD – Max. increase 3. 5% Polyamide 6/Perkalite™ (PA 6/LDH) nanocomposites FUCULTY RESEARCH DAY, 7 September 2012 ©
Results and Discussion (Composites cont. ) DMA 3, 00 E+09 Modulus (MPa) 2, 50 E+09 2, 00 E+09 1, 50 E+09 1, 00 E+09 5, 00 E+08 0, 00 E+00 %LDH loading � Perkalite FR 100 Perkalite LD Modulus at 150 C • • At 2. 5% loading, the composites displayed 62% (FR 100) and 88% (LD) increase in modulus. The trend is the same at 25, 50 and 100 C. Polyamide 6/Perkalite™ (PA 6/LDH) nanocomposites FUCULTY RESEARCH DAY, 7 September 2012 ©
Results and Discussion (Composites cont. ) XRD Polyamide 6/Perkalite™ (PA 6/LDH) nanocomposites FUCULTY RESEARCH DAY, 7 September 2012 ©
Results and Discussion (Composites cont. ) FTIR Polyamide 6/Perkalite™ (PA 6/LDH) nanocomposites FUCULTY RESEARCH DAY, 7 September 2012 ©
Results and Discussion (Composites cont. ) Tensile properties 70050 600 40 Max. Load @Yield (N) Tensile Strain (%) Tensile Modulus (MPa) 3800 3300 500 30 400 2800 30020 200 10 100 2300 1800 % LDH loading � Perkalite FR 100 Perkalite LD 00 %LD loading � � % LDH loading Perkalite FR 100 Perkalite LD LD Perkalite Polyamide 6/Perkalite™ (PA 6/LDH) nanocomposites FUCULTY RESEARCH DAY, 7 September 2012 ©
Conclusions Ø LDH have a nucleating effect on PA 6 § More pronounced on the unmodified LDH Ø Organic modification of LDH have an adverse effect on thermal stability of PA 6 Ø The stiffness of PA 6 is increased by the nanofiller § At 2. 5% loading (62% for FR 100 vs. 88% for LD) Ø The modified LDH appeared to be exfoliated while the unmodified LDH is partially intercalated § -crystal were observed in the FR 100 composited at 5% and above loading Ø An increase in the Tensile modulus was observed for both fillers Ø Maximum load at yield was observed at 2. 5% loading for both fillers (an increase of c. a. 10%) Polyamide 6/Perkalite™ (PA 6/LDH) nanocomposites FUCULTY RESEARCH DAY, 7 September 2012 ©
Recommendations Ø To perform TEM experiments § To understand the distribution of the clays (especially the unmodified) Ø To perform Rheology experiments § To determine the influence of the clays on the flow properties of the composites Polyamide 6/Perkalite™ (PA 6/LDH) nanocomposites FUCULTY RESEARCH DAY, 7 September 2012 ©
Acknowledgements • Prof. R. E. Sadiku, Prof. S. S. Ray and Dr. N. E. Luruli • The team at National Center for Nano-Structured Materials. Polyamide 6/Perkalite™ (PA 6/LDH) nanocomposites FUCULTY RESEARCH DAY, 7 September 2012 ©
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