2009 )4 (22 مجلة ابن الهیثم للعلوم الصرفة والتطبیقیة المجلد دراسة الخواص المیكانیكیة والریولوجیة لبولیمر بولي اكریلك اسید لمحالیل بولي اكریلك اسید خالدة حسین حبیب المیالي جامعة الكوفة،كلیة التربیة للبنات ،قسم الفیزیاء لخالصةا وسـعة ، وزمـن االسـترخاء، وكـذلك معامـل االمتـصاص،وسـرعة الموجـات فـوق الـسمعیة،االمتصاص عین معامل مختلفـة باسـتخدام تقنیــة وزنیــه وبنـسب المـاء المـذاب فــي أسـیدكاكـر یلــبــولیمر بـولي ل واالنـضغاطیة،واللزوجـة،االسـترخاء .ºC 30وفي درجة حرارة ) 26kHz( تردد يالموجات فوق السمعیة ذ وسـعة االسـترخاء تـزداد ، وزمـن االسـترخاء ، ومعامـل االمتـصاص النتائج ان كل من قیم السرعة واللزوجـةأظهرت لهذا البولیمر وبالعكس فان قیم االنضغاطیة تتناقص بزیادة التركیز وهذه النتیجة تقترح وجود انـدماج لمحالیل بزیادة التركیز .نفسهاأك بین جزیئات البولیمر داخلي بین جزیئات البولیمر وجزئیات المذیب وكذل IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (4) 2009 Ultrasonic and Viscosity Studies of Poly ( Acrylic Acid ) Solutions K. H.H. AL-Mayali Departme nt of Physics, College of Education for Girls, Unive rsity of Kufa Abstract Ultrasonic absorp tion, velocity , viscosity , adiabatic comp ressibility , relaxation time and relaxation amp litude measurements are reported on different concentrations of p oly(acry lic acid) solutions in common solvent water using p ulsed ultrasonic app aratus technique op erating at 26 kHz and 30 ºC. Results show an increase of velocity , viscosity , and absorption coefficient ،relaxation time and relaxation amp litude values with the increasin g concentrations of the p oly (acry lic acid) solutions, which might be the result of structural fluctuations of p oly mer molecules such as the segmental motions of t he poly mer chains. In contrast the compressibility decreases with the increasin g concentration of this p olymer. This study suggests there is an association between p olymer and solvent molecules and also there is association between p olymer molecu les itself. Introduction Poly (acry lic acid) is an unsaturated carbo xy lic acid. It read ily undergoes p oly merization and addition reactions from the monomer -CH2CH(CO2H)- . PAA is innoxious and soluble in water, it can be used in situations of alkaline and high concentration without scale sediment. PAA can disp erse the microcry stals or microsand of calcium carbonate, calcium p hosp hate and calciu m sulfate. PAA is used as sc ale inhib itor and disp ersant for circulating cool water system, p apermaking, weave, dy ein g, ceramic, p ainting, etc. PAA can be used as a scale inhib itor and disp ersant in circulating cool water sy stems in p ower p lants, iron & st eel factories, chemical f ertilizer p lants, refineries and air conditionin g sy stems. Dosage should be in accordance with water quality and equip ment materials[1,2]. IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (4) 2009 Ultrasonic absorption and velocity measurements p rovide useful information on the behaviour of p olymers in solutions. It is, therefore, imp ortant to obtain fundamental information on how this imp ortant and valuable p olymer acts in asolution, esp ecially in water[3,4]. Experimental Poly (acry lic acid) a fine white p owder has a molecular weight of 2,000 g. Its solutions were p repared by adding a known weight of the p olymer to a fixed volume of water, it was st irred for at least 20 hrs, at the temp erature 30°C . The ultrasonic velocity measurements were obtained by using the p ulsed ultrasonic technique of sender-receiver typ e (PHYWE- WEST GERM ANY) Ultrasonic generator with constant frequency of 26kHz [5]. The temp erature is maintained at 30 o C circulatin g water from a t hermost at with a thermal st ability of + 0.05 o C through the double wall jak et of t he ultrasonic e xp erimental cell. The viscosity of solutions was measured at 30 o C by using an Ostwald viscometer, the method of measurement was described elsewher e[6]. The accuracy of the viscosity measurement was +0.015%. Theoretical Calculation Theoretical values of adiabatic comp ressibility () relaxation time (), relaxation amp litude (/f 2 ), viscosity (), absorp tion coefficient (), and sp ecific acoust ic imp edance (Z) for the solutions were determined by using the following equations (5, 6, 7).  = ( 2 ) -1 …(1) 2 3 4    …(2) 32 3 8 f     …(3) ooo t t      …(4) T X  …(5) Z …(6) Where  and o are the viscosity for the solution and solvent resp ectively,  and o are the densities of the solution and the solute resp ectively,  is ultrasonic wave velocity in the solution, t, to are flow times of solution and solvent resp ectively. T is the delay time of ultrasonic waves and x is the cry st al moving distance. Re sults and Discussion The variation of the viscosity , ultrasonic velocity , absorp tion coefficient, relaxation time, relaxation amp litude and sp ecific acoust ic imp edance of Poly (acry lic acid) solutions with comp osition were shown in figures 1, 2, 3, 4, 5 and resp ectively 6 . From these figures it is clearly evident that the values of these p rop erties are increasin g with the increasin g concentrations of this p olymer. Figure (7) shows t he results for the adiabatic comp ressibility of ultrasonic waves at 26 kHz and 30 ºC as a function of p oly (acry lic acid) concentrations . IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (4) 2009 The interaction causin g association between deffer ent concentrations of Poly (acry lic acid) and water may be resp onsible for the increase in velocity , viscosity , relaxation time and relaxation amp litude [7,8,9]. The increase in the values of the acoust ic att enuation with the increase in the concentration can be att ributed to modification in the nature of the intermolecu lar interactions. These measurements suggest the formation of a more rigid st ructure with the increase of p oly(acry lic acid) concentration, p ossibly due to the p oly mer- water hy drogen bonding at sites on the p olymer's carboxy l(CO2H) group . The behaviour observed in the p oly(acry lic acid) aqueous solutions was observed in other p oly mer-water solutions [10]. The att enuation of ultrasonic energy depends on viscosity , thermal conductivity , scatt ering and inter molecular p rocesses, the thermal conductivity and scatt ering effects are known to be negligible [4,7] therefore, the inter molecular is resp onsible for the increase of the high values of the acoust ic att enuation [7,9,11], indicating an increase in the overall size of the molecule in the p ath of ultrasonic waves as a result of comp lex formation between several polymer macromolecules and solvent molecules [4, 12]. Considering viscosity as a relaxation p henomenon, the increase in the value of viscosity versus concentration of solute sup p orts t he complex formation [4,7]. In Figure 7,at 1,5,10% and 15% p oly(acry lic acid) concentration, the adiabatic comp ressibility of p oly(acry lic acid) aqueous solutions increase, from 20%, comp ressibility suddenly decreases with concentrations. This could be interp reted in terms of change in the st ructure of water and in the interaction between the p olymer and water. This relaxation p henomenon in p oly(acry lic acid) aqueous solutions might be the result of st ructural fluctuations of p olymer molecules, such as the segmental motion of p olymer chains and this behaviour suggests t he formation of more st ructures [9,7,13]. Conclustion This study shows that intermolecular p rocesses are resp onsible for the relaxation and indicating an increase in the overall size of the mo lecules in the p ath of ultrasonic wav es as a result of complex formation between Poly(acry lic acid) and solvents molecules. An u ltrasonic relaxation in p oly(acry lic acid) aqueous solutions, which may be the result of structural actuations of p oly mer molecules, such as the segmental motions of the p oly mer chains, was observed for the first time. Re ferences 1.Blmeer, F., ( 1971), “ Fundamental of p olymer Sciences”, Joho wily and sons, Inc.. 2.Shaghayegh J. and Hamid M ., ( 2005), “ A Study on Swelling and Comp lex Formationof Acry lic Acid and M ethacrylic Acid Hy drogels with Poly ethy lene Gly col” ،“Iranian Polymer Journal”,14 (10):863-873. 3.Hiroy asu, N.; Tatsuro, M. and Shinobu, K. ( 2004), “Ultrasonically induced birefringence in polymer solutions”, “ Pure App l. Chem. ”,. 76(1): 97–104. 4.Hassun, S. and Rahman, K., (1989)Ultrasonic Study of M olecularer association of high I mpact Polysty rene Solutions in Toluene (1990)Iraqi J. Sci. 30:3-24. 5.Blitz, J. (1967).Fundamental of Ultrasonic 2nd eedion, 6.Khalida, H.H.; Alaa, F. and Salh, H. (2006) Study of Temp erature Effect of some Rheological and Electrical Prop erties of Poly isobutylene ,Journal of Babylon University”, 13(3):530-538. 7.Khalida, H. H., (2004), Study of Structural and Visco-Relaxation of Poly carbonates Solutions by Ultrasonic Technique”,“Journal of Al-Qadisiya of Pure Sciences 9(3):118-122. 8.M assoumeh, F. ( 2006) Density Dep endence of the Viscosity and Excess Volume of Aqueous Solutions of Poly vinylpy rrolidone”, “Acta Chim. Slov., IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (4) 2009 53:219–222 . 9.Sy al ,V.K.;Anita ,Ch. and Suvarch a, Ch.. (2005), Ultrasonic velocity , viscosity and density studies of p oly (ethy lene gly cols)(PEG - 8,000, PEG - 20,000) in acetonitrile (AN) and water (H2O) mixtures at 250C, J. Pure App l Ultrason 27: 61-69. 10.Jong ,R.B. (2002) Ultrasonic Velocity and Absorption M easurements in Binary Solutions, Journal of the Korean Phy sical Society , 41(1):171-174. 11.Rajulu, A.V. and Redlody, R.L., (2000) M iscibility Studies of Polystyrene Blends as M easured by Viscosity , Ultrsonic, and Refractiv Index M ethods, J. Poly meric M ater, 5:467. 12.M affezzoli, A.; Tarziq, A. and Cannoletta, D.(1999) Ultrasonic Characterization of the Kineties of Water Sorp tion in Hy drogels, M acromol Sy mp. 138(144): 149-154. 13.Hassun, S.K. and Isa, S.O. (1989) Visco-R elaxation Study of Poly (Vinyl a lcohol) aqu eous Solution (A M ethod for the Determination of M olecular Weight)”,“British p oly mer Journal, 21: 333. Fig.( 1): The variati on of Viscosity wi th Concen tration of Po ly(acr ylic acid ) at 30 هC . 1.E-02 2.E-02 4.E-02 5.E-02 7.E-02 8.E-02 9.E-02 0 5 10 15 20 25 30 35 Conc entration w t% of P oly(acrylic acid) V is c o s it y ( p o is e) IBN AL- HAITHAM J . FO R PURE & APPL. SC I VO L.22 (4) 2009 Fig.( 2) The vari ation of Veloci ty with Concentration of Poly(acrylic aci d ) at 30 ه C . 1500 1520 1540 1560 1580 1600 0 5 10 15 20 25 30 35 Co ncentrati on wt% V e lo c it y ( m /s ) Fig. ( 3): The variation of absorption c oefficient of ultrasonic w aves with the Concentration of Poly(acrylic acid) at 30 ه C . 1.0E-05 2.1E-04 4.1E-04 6.1E-04 8.1E-04 1.0E-03 1.2E-03 1.4E-03 0 5 10 15 20 25 30 35 Concentration wt% of Poly(acrylic acid . A b s o rp ti o n c o e ff ic ie n t ( m -1 ) IBN AL- HAITHAM J . FO R PURE & APPL. SC I VO L.22 (4) 2009 Fig.( 4): The variation of relaxation time with the Concentration of Poly(acrylic aci d) at 30 ه C . 3.E-12 2.E-11 4.E-11 6.E-11 8.E-11 1.E-10 1.E-10 1.E-10 0 5 10 15 20 25 30 35 Concentrat ion wt% of Pol y(acrylic acid R e L a x a ti o n t im e ( s ) Fig.( 5) The variation of relaxation amplitude with the Concentration of Poly(acrylic acid) at 30 ه C . 2.0E-14 3.2E-13 6.2E-13 9.2E-13 1.2E-12 1.5E-12 1.8E-12 2.1E-12 0 5 10 15 20 25 30 35 C onc entr ation wt% of Poly(acr ylic acid . R e la x a ti o n A m p li tu d e ( s 2 / m ) . IBN AL- HAITHAM J . FO R PURE & APPL. SC I VO L.22 (4) 2009 Fig.( 6): The variation of specifi c acoustic impedance with the Concentration of P oly(acrylic acid) at 30 ه C . 25000 33000 41000 49000 57000 65000 73000 81000 89000 97000 0 5 10 15 20 25 30 35 Concentration wt% of Poly(a cryli c acid ( g / ml ) . S p e c if ic A c o u s ti c I m p e d a n c e ( k g / m 2 . s ) Fig .( 7): T he variatio n o f compressibility with the Concentration of Po ly(acrylic acid ) at 30 ه C . 6.E-09 9.E-09 1.E-08 2.E-08 2.E-08 2.E-08 2.E-08 0 5 10 15 20 25 30 35 Concentra tion wt% of Poly(acrylic acid ( g / m l ) . C o m p re s s ib il it y ( m . s 2 / k g )