Preparation of Polyurethane Acrylate/ Organically Modified Montmorillonite Nanocomposites by
Electron Beam Radiation Curing
By
Dr. Ashraf Salih
Sudan Atomic Energy CommissionP. O Box 3001, Khartoum, Sudan
27/04/2017
Introduction
Sudan Atomic Energy Commission
• Polyurethanes (PUs) are hetrochain polymerscharacterized by repeated units contain carbamate(urethane) –NH-CO- groups.
• The continuous elevation in petroleum prices, its impacton the environment, increasing demands for renewable,environmentally friendly source for the industrialproduction of polymers.
• Although the polyurethane acrylate has excellent properties,still it has low modulus and tensile strength. Incorporation oflow amount of clay will enhance the mechanical properties.
4/28/2017 2
Introduction
• Radiation curing is a process of converting liquid prepolymers and monomers into a solid cured films.
• The energy of the UV radiation or the electron beam is used to induce free radical polymerization, and thus curing of the polymer films take place.
• Advantages: can be performed at room temperature, with a fast curing rate, No volatile chemicals.
Sudan Atomic Energy Commission4/28/2017 3
Introduction
Sudan Atomic Energy Commission4/28/2017 4
• EB has been used in different applications of resin. such asacrylate composites (Vautard et al., 2011), epoxy acrylateresins for conductive films application, curing of thermoset-thermoplastic blend (Alessi et al., 2011), epoxy/claynanocomposites (Khaksari et al., 2013) and polyurethanenanocomposites for coating application (Steele et al., 2012).
• Electron beam radiation was found to be an excellentmethod for the rapid curing without using of chemicalinitiators. Therefore, it is an environmentally friendlytechnique (Alessi et al., 2007b; Mascioni et al., 2013; Sui etal., 2003).
Objective of the Study
To Investigate the electron beam
radiation-induced curing of palm oil
based polyurethane acrylate/clay
nanocomposites.
Sudan Atomic Energy Commission4/28/2017 5
Experimental
Sudan Atomic Energy Commission4/28/2017 6
Polyurethane Acrylate (PUA)+ Reactive
monomers
ODA-MMTstirringSonication at 25°C
Casting in Al-mold with thickness≈
1mm
EB Curing with different doses
Coating in glass substrate
thickness≈ 20μm
Experimental
Sudan Atomic Energy Commission
Formula
PUA
(g)
TMPTA
(g)
DPGDA
(g)
Mono-Ac
(g)
Filler (%)
PUA 7.00 0.70 1.40 2.80 0
PUA-ODA-
MMT
7.00 0.70 1.40 2.80 1,3,5, ODA-MMT
PUA-MMT 7.00 0.70 1.40 2.80 1,3,5, Na-MMT
The Typical Formulation of the PUA/ODA-MMT Nanocomposites Films
4/28/2017 7
Characterization
Sudan Atomic Energy Commission
Morphology
XRD
TEM
Chemical structure FTIR
Mechanical Properties
Tensile
Test
DMA
4/28/2017 8
Results & Discussion/ FTIR
Sudan Atomic Energy Commission
The nanocomposites spectra displayed an absorption IR bands at 1035 cm-1 (Si-O-Si, Si-O-C) asymmetric stretching vibration, the stretching band of Si-OH at 954 cm-1, Si-O-C deformation at 833 cm-1, Mg-O bending vibration at 515 cm-1, therefore the ODA-MMT was successfully dispersed in the PUA matrix.
4/28/20179
Results & Discussion/ XRD
The distance between the silicate layers was increased due to the intercalation of the PUA chains in the gallery spacing. The microcomposite sample with pristine MMT 5 wt% displayed diffraction peak at 2θ = 7.9° corresponding to d spacing about 11.9 Å, revealing the poor interaction between the pristine MMT and PUA matrix.
4/28/2017 10Sudan Atomic Energy Commission
Results & Discussion/ TEM
Sudan Atomic Energy Commission
TEM micrographs of (A) PUA/MMT 5 wt% at low magnification, (B)PUA/MMT 5 wt% at high magnification, (C) PUA/ODA-MMT 3 wt%, and (D)PUA/ODA-MMT 5 wt%.
4/28/2017 11
Results & Discussion/ DMA
Sudan Atomic Energy Commission4/28/2017 12
• The presence of the ODA-MMT in the PUA matrix led to decrease the segmentalmotions, and increase significantly the storage modulus of the PUA in the glassystate.
• E’ values in the rubbery state were lower than in the glassy state.
Results & Discussion/ DMA-Tan δ
Sudan Atomic Energy Commission4/28/2017 13
• The 3 wt% ODA-MMT led to elevate the Tg value to 65.1°C (From 37.9°C), and no significant change could be found when the amount increased to 5 wt%, (Tgwas about 64.38°C)
Results & Discussion/ Mechanical
Properties
Sudan Atomic Energy Commission4/28/2017 14
• These results revealed that the stiffness of the PUA was increased by incorporation of the organoclay.
Results & Discussion/ Effect of Radiation
Dose
Sudan Atomic Energy Commission4/28/2017 15
60
65
70
75
80
85
90
95
0 20 40 60 80 100 120 140 160
Ge
l co
nte
nt
(%)
Radiation dose (kGy)
• The gel fraction in the PUA nanocomposites films increased with the radiation doses.
Results & Discussion/ Effect of TMPTA
Content
Sudan Atomic Energy Commission4/28/2017 16
50
55
60
65
70
75
80
85
90
95
100
0 10 20 30 40 50
Ge
l c
on
ten
t (%
)
TMPTA amount (%)
• The increase of the TMPTA amount, resulted in a significant increase in the gel fraction in of the PUA nanocomposites films.
Conclusion• EB curing produced nanocomposites, with remarkable
improvement in the thermal, mechanical and morphologicalproperties, compared to the pristine PUA.
• The nanocomposites prepared by Eb showed betterProperties.
• The Young`s modulus increased from 8.53 to 132.43 MPaand the tensile values were also increased significantlyfrom 1.54 to 11.11 MPa.
• The storage modulus value from 17 to 40 MPa, innanocomposites with 3 wt% ODA-MMT nanocomposites.
Sudan Atomic Energy Commission4/28/2017 17
4/28/2017 Sudan Atomic Energy Commission 18
Alessi, S., Dispenza, C., Pitarresi, G., & Spadaro, G. (2011). Radiation curing of thermosetting-
thermoplastic blends as matrices for structural carbon fibre composites Advances in
Composite Materials-Ecodesign and Analysis (pp. 125-140). Rijeka: In Tech.
Alessi, S., Dispenza, C., & Spadaro, G. (2007). Thermal Properties of E-beam Cured
Epoxy/Thermoplastic Matrices for Advanced Composite Materials. Macromolecular
Symposia, 247, 238-243.
Khaksari, M., Ahmadi, S. J., Moosaviyan, S. M. A., & Nazeri, M. (2013). Effect of electron beam
irradiation on thermal and mechanical properties of epoxy/clay nanocomposites. Journal of
Composite Materials, 47(28), 3517-3524.
Mascioni, M., Ghosh, N. N., Sands, J. M., & Palmese, G. R. (2013). Electron beam and UV
cationic polymerization of glycidyl ethers – part I: Reaction of monofunctional phenyl
glycidyl ether. Journal of applied polymer science, 130, 479-486. doi: 10.1002/app.39184
Steele, A., Bayer, I., & Loth, E. (2012). Adhesion strength and superhydrophobicity of
polyurethane/organoclay nanocomposite coatings. Journal of applied polymer science,
125(S1), E445-E452.
Sui, G., Zhang, Z.-G., Chen, C.-Q., & Zhong, W.-H. (2003). Analyses on curing process of electron
beam radiation in epoxy resins. Materials Chemistry and Physics, 78, 349-357.
Vautard, F., Fioux, P., Vidal, L., Schultz, J., Nardin, M., & Defoort, B. (2011). Influence of the
carbon fiber surface properties on interfacial adhesion in carbon fiber–acrylate composites
cured by electron beam. Composites Part A: Applied Science and Manufacturing, 42(7), 859-
867.
References
Thank you
Sudan Atomic Energy Commission4/28/2017 19