International Journal of Application or Innovation in Engineering & Management (IJAIEM)
Web Site: www.ijaiem.org Email: editor@ijaiem.org, editorijaiem@gmail.com
Volume 2, Issue 11, November 2013
ISSN 2319 - 4847
Study of the Optical Constants of the PVC/
PMMA Blends
Rouaramadan1,Ekramajaj2 ,Ahmad A. Hasan3
1,2,3
Department of physics,College of Science,University of Baghdad
Abstract
The aim of the present work is concerned with the study of the optical constants of the PVC/ PMMA blend at different ratio, were
prepared with different concentration(%PVC,75%PVC+25%PMMA,50%PVC+25%PMMA,25%PVC+75%PMMA,PVC) using
Casting Technique with thickness about (0.078,0.094,0.054,0.078,0.052) . The absorption spectra of PVC/PMMA blends at
different concertation showed absorption changes in the wavelength range, which depends on the polym er type, and the
concentration of the polymer blends. It was found that 50%PVC+50%PMMA ratio from these polymers showed higher absorption
values in comparison with the other blend. The absorption spectra has been recorded in the wavelength range (200-1100)nm . The
absorption coefficient(α), extinction coefficient(k), refractive index(n) have been evaluated.
Keywords:Optical constants, Optical properties,PVC/PMMA blend.
1. INTRODUCTION
Polymeric materials have attracted the scientific and technological researchers, because of their wide applications. This is
mainly due to the lightweight, good mechanical strength, optical properties and makes them to be multifunctional
materials. Optical properties of polymers constitute an important aspects in study of electronic transition and the
possibility of their application as optical filters, a cover in solar collection, selection surfaces and green house. The
information about the electronic structure of crystalline and amorphous semiconductors has been mostly accumulated
from the studies of optical properties in wide frequency range[1].
PMMA is one of the earliest and best known polymers. PMMA was seen as a replacement for glass in a variety of
applications and is currently used extensively in glazing applications. The material is one of the hardest polymers, and is
rigid, glass-clear with glossy finish and good weather resistance. PMMA is naturally transparent and colorless. The
transmission for visible light is very high. Polymeric composites of PMMA are known for their importance in technical
applications.[2]
Poly(methyl methacrylate) is one of the best organic optical materials and has been widely used to make a variety of
optical devices, such as optical lenses. It is known that its refractive index changes upon UV irradiation, either in the pure
[3, 4] or doped state [5], which provides ameans to fabricate structures, such as gratings or waveguides.
Polyvinylchloride (PVC) is one of the most important commercial polymers that have wide range of applications[6].
Polyvinylchloride (PVC) is a linear, thermoplastic, substantially amorphous polymer, with a huge commercial interest,
due to the accessibility to basic raw materials and to its properties Incorporating plasticizers the rigid PVC makes the soft
PVC products and it has been used in cable and wide covers, children toys and medical devices.[7]
M..Ahemed [8] prepared transparent films of (PMMA/PVAc) blend with different concentrations by using solution cast
technique. FTIR transmission spectra were carried out for the samples to detect the influence of UV radiation. In addition,
optical absorption measurement was carried out for the samples at room
temperature across the 190-900nm wavelength region before and after exposure to UV and filtered radiation using Xenon
arc lamp. The study had been also extended to include the changes in the optical parameters including the band tail width
and band gap energies for the samples. Moreover, the refractive index was calculated for samples from reflection and
absorption spectrum before and after exposure to UV and filtered radiation. The results showed no minimum was found
by absorption in the visible wavelength, which points to the fact that all the samples are colorless. In addition, the
increase in the values of refractive index after exposure to UV radiation for 24 hours could be attributed to the increasing
in localized density arising from photo induced cross-linking. L. JOSHI et al [9] study The polyblend of polyvinyl
chloride (PVC) and polystyrene (PS), in the weight ratio 5: 1 using 1.25 gm of PVC and 0.25 gm of PS by casting method
. The two polymers PVC and PS and dopant Polyaniline dissolved seperately in tetrahydrofuran. Polyaniline (PANI) has
been used as dopant and with 0.5 %, 1.0%, 1.5%, 2.0% and 2.5 % of the total weight of the two polymers they
preparedfivesamplesTheamorphousnature in all samples were observed from XRD. On the basis of optical absorbance and
transmittance measurements at normal incidence of light in the wavelength range 500- 1000 nm,the absorption
coefficient (α), optical energy gap (Eopt), refractive index (n0), optical dielectric constant (ϵ), constant (B) and ratio of
carrier concentration to the effective mass(N/m*) have been reported for polyaniline doped PVC-PS blend.They found
The behavior of all the optical parameters found to be non-linear. It can be concluded that the evaluated optical
parameters such as absorption coefficient, optical energy gap, optical dielectric constant, refractive index, constant B,
measure of extent of band tailing (n0B)-1 are found to be bidden direct transition.The refractive index (no) calculated in
Volume 2, Issue 11, November 2013
Page 240
International Journal of Application or Innovation in Engineering & Management (IJAIEM)
Web Site: www.ijaiem.org Email: editor@ijaiem.org, editorijaiem@gmail.com
Volume 2, Issue 11, November 2013
ISSN 2319 - 4847
the region 500 to 1000 nm is found to be non-linear. The ratio of carrier concentration to the effective mass N/m*is found
to be of the order of 1021cm-3.
G.Patel et al [10] .They study PVC/PMMA polymer blends were characterized by Fourier Transform Infrared
Spectroscopy (FTIR), UV‐VIS Spectroscopy and mechanical analysis. The changes in mechanical properties are reflected
by the changes in the IR spectrum. The mechanical properties of such poly blends revealed a substantial increase in
Young’s modulus and ultimate tensile strength after initial drop at 10% of PMMA. Optical properties such as the
absorption coefficient, optical (Direct/Indirect) energy gap were calculated. The effects of different blending percentage
on these parameters have been discussed and their results are co‐related with IR study.
2. Experimental part
2.1 Raw Material
PVC(polyvinyclorid) and PMMA (poly methyl methacrylate) was used in this study were obtained from Sigma, Aldrich
(Germany) and reported to have molecular weights of 93.92605 and
996000 g/mol respectively. Tetrahydorfuran
(THF) has purity 99.8% optainedfrom (G.I.D.C) in England used as a common solvent for PVC and PMMA .
2.2 Preparation of the Samples
Two polymers PVC (1g) and PMMA (1g) were add in 10 ml of tetrahydorfuran (THF), allowing them to dissolve
completely,
The
two
solutions
were
mixed
together
with
different
concentrations(%PVC,75%PVC+25%PMMA,50%PVC+50%PMMA,25PVC+75PMMA,%PMMA) by weight with
thickness about (0.078,0.094,0.054,0.078,0.052) ,and subsequently cast clean glass beterdish of(7.5cm) in diameter
placed on plate form, and left in hood at room temperature for 24 hours to form transparent films. The dried film was
then removed easily by using tweezers clamp.
3. Results and Discussion
The optical constants are very important because they describe the optical behavior of the materials. The absorption
coefficient of the material is very strong function of photon energy and band gap energy [11]. The variation of
absorption with wavelength of the incident light the absorption were recorded using double bean schimadzu UV/VIS1650 PC in the wavelength optical a range (200-1100) nm for polymer blend .
Figure. (1) The figure show absorption spectrum in rang(200-1100)nm reveals a strong absorption probability below
250-290nm respectively. For% PVC, 75%PVC+25%PMMA,50%PVC+50%PMMA,25%PVC+75%PMMA,%PMMA
there is sudden decrease in the absorption values observed above the limits. For 50%PVC+50%PMMA the decrease was
even slower. 50%PVC+50%PMMA blend showed the hightapsorption than the other blend for polymer blend. and all
the films showing the same behavioun but the absorption was decrease at %PMMA.
Figure (1): Variation of absorption for (PVC/PMMA) with wavelength.
Absorption coefficient (α) is defined as the ability of a material to absorb the light of a given wavelength[12].
(1)
Where A: is the absorption of the material
t: the sample thickness in cm.
Figure (2) shows the relationship of the absorption coefficient with photon energy of different weight percentages of
PVC/PMMA . it show hight absorption edge for PVC,whil it becomes less for PMMA
Figure( 2): Absorption coefficient for (PVC/PMMA) photon energy
Volume 2, Issue 11, November 2013
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International Journal of Application or Innovation in Engineering & Management (IJAIEM)
Web Site: www.ijaiem.org Email: editor@ijaiem.org, editorijaiem@gmail.com
Volume 2, Issue 11, November 2013
ISSN 2319 - 4847
The variation of refractive index (n) The refractive index (n) can be measured (when the reflectance (R) and (k) are
known) by using the equation(2) [13].
(2)
where k is the extinction coefficient and R is the optical reflectance. The extinction coefficient can be obtained from the
relation equ (4)where[14].
k=
(4)
Figure (3) Shows the variation of n as a function of wavelength, the value of the refractive index In order to compare our
results of (n) for PMMA with the published data, which were calculated at 600 nm. The value of (n) was found (1.85) for
thickness (20 μm), while Ahmed et al.[15] ,obtained (n) value = 2.13 with the thickness 100 μm, Papanu et al[16]
.obtained (n) value = 1.48 of PMMA with thickness 1 μm deposited on silicon wafer. The difference in (n) value is
attributed to the difference in thickness.
Figure (3) Refractive indices as a function of wavelength for polymer blend
Figure(4) shows the variation of extinction coefficient (k=αλ/4π) with wave length(λ) . The blend 50%PMMA/50%PVC
concentration has the highest value of (k), and it was displaced toward the long wavelength.
Figure (4) Extinction coefficient as a function of wavelength for PVC/PMMA
Table (1): Represents the parameters of optical properties of polymer blend(PVC/PMMA)at 550nm
Polymer blend
%PVC
75%PVC+25%PMMA
50%PVC+50%PMMA
25%PVC+75%PMMA
%PMMA
α (1/cm)
307.066
100.45
306.163
294.94
15.77
A%
0.89
1
1.13
0.41
0.05
K*10-3
1.35E-03
1.1E-03
1.34E-03
4.4E-03
6.91E-05
n
2.528974
2.562835
2.587151
1.977411
1.288341
Conclusion
1- Strong absorption clear between 200-290nm respectively.
2-50%PVC/50%PMMA blend showed the best optical properties.
3-The absorption coefficient,extinctioncoefficient,refractive index of (50/50)%PVC/PMMA show significant change from
samples in compored with other blend samples.
Refrence
[1] G.Pinto and A.Maaroufi,"Critical filler concentration for electro conductive polymer composites", Society of Plastics
Engineers (SPE),2011.
Volume 2, Issue 11, November 2013
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International Journal of Application or Innovation in Engineering & Management (IJAIEM)
Web Site: www.ijaiem.org Email: editor@ijaiem.org, editorijaiem@gmail.com
Volume 2, Issue 11, November 2013
ISSN 2319 - 4847
[2] T.Hamad, M. Abdul nabi and W.Musa,” The optical properties of Poly methyl methacrylate (PMMA) polymers
doped by Potassium Iodide with different thickness”, Vol.8(2)” Baghdad Science Journal”, pp.538-542,2011.
[3] C.Wochnowski, S. Metev, and G. Sepold, “UV—laser-assisted modification of the optical properties of
polymethylmethacrylate,” Applied Surface Science, vol. 154,pp. 706–711, 2000.
[4] A. Baker and P. Dyer, “Refractive-index modification of polymethylmethacrylate (PMMA) thin films by KrF-laser
irradiation,” Applied Physics A, vol. 57, no. 6, pp. 543–544,1993.
[5] T. Kardinahl and H. Franke, “Photoinduced refractive-index changes in fulgide-dopedPMMAfilms,” Applied Physics
A, vol. 61, no. 1, pp. 23–27, 1995.
[6] Wang Q.; Storn B. K.; Polymer Testing, 24,290.2005.
[7] B.Balakrishnan, A. Jayakrishnan, “Chemical modification of poly (vinyl chloride) using poly (ethylene glycol) to
improve blood compatibility”, in Trends in Biomaterials and Artificial Organs, vol. 18, no. 2, pp. 230-236,2005.
[8] M.Ahmed"Optical Study on Poly (methylmethacrylate)/ Poly (vinyl acetate) Blends", Vol.57, No.10 "International
Journal of Polymeric Materials", pp.969-978,2008.
[9] L.Joshi, M. Deshmukh, P. Deshmukh, D.burghate and S. Shilaskar “Optical Band Gap in Polyaniline Doped PVCPS Blend” J. Polym. Mater. Vol. 28, No. 1,pp.93-100,2011.
[10] G.Patel,M. Sureshkumar and P. Patel, Kerala, (India), AIP Conf. Proc. 1391, 645 (2011).
[11] E. Mizher ., Ph. D,, PhD Thesis, "University of Baghdad, College of Science", (2005).
[12] S. Hutagalwng. and B.Lee,2007, Proceeding of the 2nd international conference Nano/Micro Engineered and
Molecular systems, January ,Bangkok,Thailand.
[13] J.L.Pankov, Optical Process in Semiconductors, London(1971).
[14] M.Balkanski"Optical Properties of Solids"Vol.2, Amsterdam, New York.Oxford (1992).
[15] A. Ahmad, A.Awatif and N. Majied, Eng. and Technology, Vol. 25(4), Pp. 558, (2007).
[16] J. Popanu, D. Hess, D. Soane and A. T. Bell, Polym. Sci., Vol. 39, pp. 303, (1990).
My name is rouaramadan received the B.S.degrees in physics science from university of Baghdad in 2011.At present
student of M.SC. in the same science and university.I have this paper and I hope to puplish it in your journal.Greetings to
all.
Volume 2, Issue 11, November 2013
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