The solvent transport properties of the prepared composites were analysed using solvents of varying cohesive energy density and the effect of both modified as well as unmodified filler on the sorption and diffusion behaviour of NR vulcanisates has been investigated. It is found that the equilibrium uptake decreases with increase in filler content, as anticipated owing to the restrictions offered by the filler for solvents to diffuse into the polymer matrix. The mechanism of transport in natural rubber composites was carefully tracked and it was found to exhibit an anomalous mode of solvent transport where the polymer relaxation is in par with the rate of diffusion. Theoretical modelling of the swelling parameters was done and the results were found to be in agreement with existing models. The excellent swelling resistance coupled with the simultaneous improvement in mechanical properties would definitely pave way for the utilisation of these composites as barrier membranes.
CrankJ. and ParkG. S.: ‘Diffusion in polymers’, 452; 1968, London, Academic Press.
2.
VeselyD.: ‘Diffusion of liquids in polymers’, Int. Mater. Rev., 2008, 53, (5), 299–315. doi: 10.1179/174328008X324602
3.
MajumderM., ChopraNitin and HindsBruce J.: ‘Mass transport through carbon nanotube membranes in three different regimes: ionic diffusion and gas and liquid flow’, ACS Nano, 2011, 5, (5), 3867–3877. doi: 10.1021/nn200222g
4.
VargheseS., KuriakoseB., ThomasS. and JosephK.: ‘Effect of adhesion on the equilibrium swelling of short sisal fiber reinforced natural rubber composites’, Rubber Chem. Technol., 1995, 68, 37. doi: 10.5254/1.3538730
5.
UnnikrishnanG. and ThomasS.: ‘Molecular transport of benzene and methyl substituted benzenes into filled natural rubbers’, J. Appl. Polym. Sci., 1996, 60, 963–970. doi: 10.1002/(SICI)1097-4628(19960516)60:7<963::AID-APP6>3.0.CO;2-K
6.
DasB.: ‘Restricted equilibrium swelling – a true measure of adhesion between short fibers and rubber’, J. Appl. Polym. Sci., 1973, 17, 1019–1030. doi: 10.1002/app.1973.070170403
7.
DorigatoA., D'AmatoM. and PegorettiA.: ‘Thermo-mechanical properties of high density polyethylene – fumed silica nanocomposites: effect of filler surface area and treatment’, J. Polym. Res., 2012, 19, (6), 1–11. doi: 10.1007/s10965-012-9889-2
8.
VargheseSiby and Karger KocsisJ.: ‘Natural rubber based nano composites by latex compounding with layered silicates’, Polymer, 2003, 17, 4921–4927. doi: 10.1016/S0032-3861(03)00480-4
9.
RongM. Z., ZhangM. Q. and RuanW. H.: ‘Surface modification of nanoscale fillers for improving properties of polymer nanocomposites: a review’, Mater. Sci. Technol., 2006, 22, (7), 787–796. doi: 10.1179/174328406X101247
10.
ShanmugharajA. M., BaeJ. H., LeeKwang Yong, NohWoo Hyun, LeeSe Hyoung and RiuSun Hung: ‘Physical and chemical characteristics of multiwalled carbon nanotubes functionalized with amino silane and its influence on the properties of natural rubber composites’, Compos. Sci. Technol., 2007, 9, 1813–1822. doi: 10.1016/j.compscitech.2006.10.021
11.
GuadagnoLiberata, VertuccioLuigi, SorrentinoAndrea, RaimondoMarialuigia, NaddeoCarlo, VittoriaVittoria, LannuzzoGeneroso, CalviErika and RussoSalvatore: ‘Mechanical and barrier properties of epoxy resin filled with multi-walled carbon anotubes’, Carbon, 2009, 47, (10), 2419–2430. doi: 10.1016/j.carbon.2009.04.035
12.
Abdul RahimN. A., AriffZ. M., AriffinA. and JikanS. S.: ‘Study on effect of filler loading on the flow and swelling behaviors of polypropylene-kaolin composites using single-screw extruder’, J. Appl. Polym. Sci., 2011, 119, (1), 73–83. doi: 10.1002/app.32541
13.
SujithA., UnnikrishnanG., RadhakrishnanC. K. and PadminiM.: ‘Interaction of silica and carbon black fillers with natural rubber/ethylene-co-vinyl acetate matrix by swelling studies’, Polym. Compos., 2007, 28, 705–712. doi: 10.1002/pc.20340
14.
MathewLovely, JosephK. U. and JosephRani: ‘Swelling behavior of isora/natural rubber composites in oils used in automobiles’, Bull. Mater. Sci., 2006, 29, (1), 91–99. doi: 10.1007/BF02709362
15.
MostafaA., Abouel-KasemA., BayoumiM. R. and El-Sebaie: ‘Effect of carbon black loading on the swelling and compression set behavior of SBR and NBR rubber compounds’, Mater. Des., 2009, 30, (5), 1561–1568. doi: 10.1016/j.matdes.2008.07.043
16.
SarithaA., JosephK., BoudenneA. and ThomasS.: ‘Mechanical, thermophysical, and diffusion properties of TiO2-filled chlorobutyl rubber composites’, Polym. Compos., 2011, 32, 1681–1687. doi: 10.1002/pc.21205
17.
XieYanjun, HillCallum A. S., HeaoZefang, MilitzHoiger and MaiCarsten: ‘Silane coupling agents used for natural fiber/polymer composites: a review’, Compos. Part A – Appl. Sci. Manuf., 2010, 41, (7), 806–819. doi: 10.1016/j.compositesa.2010.03.005
18.
JensenH., PedersenJ. H., JorgensenJ. E., Skov PedersenJ., JoensenK. D., IversenS. B. and SogaardE. G.: ‘Determination of size distributions in nano sized powders by TEM, XRD and SAXS’, J. Exp. Nanosci., 2006, 1, 355–373. doi: 10.1080/17458080600752482
19.
The XRD, SAED patterns and d values were indexed with reference to the crystal structures from the PCPDF files (PCPDF card no.00-012-0797).
20.
ChasseWalter, LangMichael, SommerJens-Uwe and SaalwachterKay: ‘Cross-link density estimation of PDMS networks with precise consideration of networks defects’, Macromolecules, 2012, 45, (2), 899–912. doi: 10.1021/ma202030z
21.
FloryP. J. and RehnerJ.: ‘Statistical mechanics of cross-linked polymer networks I. Rubber elasticity’, J. Chem. Phys., 1943, 11, 512–515. doi: 10.1063/1.1723791
22.
FloryP. J.: ‘Principles of polymer chemistry’; 1953, Ithaca, NY, Cornell University Press.
23.
StephenRanimol, VargheseSiby, JosephKuruvilla, OommenZachariah and ThomasSabu: ‘Diffusion and transport through nanocomposites of natural rubber (NR), carboxylated styrene butadiene rubber (XSBR) and their blends’, J. Membr. Sci., 2006, 282, (1–2), 162–170. doi: 10.1016/j.memsci.2006.05.019
24.
VisakhP. M., ThomasSabu, OksmanKristiina and MathewAji P.: ‘Cellulose nanofibres and cellulose nanowhiskers based natural rubber composites: diffusion, sorption, and permeation of aromatic organic solvents’, J. Appl. Polym. Sci., 2012, 124, (2), 1614–1623. doi: 10.1002/app.35176
25.
PriyadasanK., UnnikrishnanG. and PurushothamanE.: ‘Solvent transport through carbon-black filled poly (ethylene-co-vinyl-acetate) composites’, eXPRESS Polym. Lett., 2008, 5, 382–390. doi: 10.3144/expresspolymlett.2008.45
26.
ThomasN. L. and WindleA. H.: ‘Discontinuous shape changes associated with case II transport of methanol in thin sheets of PMMA’, Polymer, 1977, 18, 1195. doi: 10.1016/0032-3861(77)90122-7
27.
SouthernE. and ThomasA. G.: ‘Effect of constraints on the equilibrium swelling of rubber vulcanizates’, J. Polym. Sci. (A), 1965, 3, 641–646.
28.
MaitiMadhucchanda and BhowmickAnil K.: ‘Effect of polymer–clay interaction on solvent transport behavior of fluoroelastomer–clay nanocomposites and prediction of aspect ratio of nanoclay’, J. Appl. Polym. Sci., 2007, 105, (2), 435–445. doi: 10.1002/app.26052
29.
HiguchiT.: ‘Mechanism of sustained action medication. Theoretical analysis of rate of release of solid drugs dispersed in solid matrices’, J. Pharm. Sci, 1963, 84, 1464–1477.
30.
KorsmeyerR. W., GurnyR., DoelkerE., BuriP. and PeppasN. A.: ‘Mechanisms of solute release from porous hydrophilic polymers’, Int. J. Pharm, 1983, 15, 25–35.
31.
PeppasNikolaos A. and SahlinJennifer J.: ‘A simple equation for the description of solute release. III. Coupling of diffusion and relaxation’, Int. J. Pharm., 1989, 57, 169–172. doi: 10.1016/0378-5173(89)90306-2
32.
CrankJ.: ‘The mathematics of diffusion’; 1957, Oxford, Clarendon Press.
33.
MariaHanna J., LyczkoNathalie, NzihouAnge, MathewCherian, GeorgeSoney C., JosephKuruvilla and ThomasSabu: ‘Transport of organic solvents through natural rubber/nitrile rubber/organically modified montmorillonite nanocomposites’, J. Mater. Sci., 2013, 48, (15), 5373–5386. doi: 10.1007/s10853-013-7332-7
34.
SiepmannJ. and PeppasN. A.: ‘Modeling of drug release from delivery systems based on hydroxypropyl methylcellulose (HPMC)’, Adv. Drug Deliv. Rev., 2012, 64, 163–174. doi: 10.1016/j.addr.2012.09.028
