Preparation of acrylamide/2-ethylhexyl acrylate copolymer and calculation of monomer reactivity ratios

Transcription

1 Bulgara Chemcal Commucatos, Specal Issue F, (pp ) 2016 Preparato of acrylamde/2-ethylhexyl acrylate copolymer ad calculato of moomer reactvty ratos M. Ta, Y.J. Xu* School of Chemstry ad Chemcal Egeerg, Harb Isttute of Techology, Harb , Cha Receved February, 2016; Revsed December 26, 2016 Recetly, avalable petroleum resources o the earth are beg exhausted gradually whle ts cosumpto s creasg. To mprove ol recovery yeld, a ew profle cotrol aget has bee developed ad reported here for scetfc ad applcato cocers. Acrylamde (AM)/ 2-Ethylhexyl acrylate(2-eha)copolymer s a expesve profle cotrol aget, but t s ot facle to regulate the cotrollable factors durg the preparato of AM/2-EHA copolymer. Hece, t s ecessary to clarfy the copolymerzato mechasm whch are related to the moomer reactvty rato. The copolymerzato of AM ad 2-EHA by free radcal copolymerzato method was studed. Based o the copolymer composto obtaed by FT-IR method reactvty rato was determed by Yezrelev-Brokha-Rosk method. The result dcates that the reactvty ratos of AM ad 2-EHA are ad respectvely. The effect of temperature o the reactvty ratos was also dscussed. It ca be a sgfcat quattatve referece for dustral producto. Keywords: Reactvty Rato, FT-IR, Acrylamde, Copolymer 74 INTRODUCTION Recetly, avalable petroleum resources o the earth are beg exhausted gradually whle ts cosumpto s creasg. The ecessty for ehacg ol recovery becomes mperatve [1, 2]. Acrylamde (AM)/2-Ethylhexyl acrylate (2-EHA) copolymer s a expesve profle cotrol aget wth propertes of thermal stablty, alkal tolerace ad salt resstace [3, 4], but t s ot facle to regulate the cotrollable factors durg the preparato of AM/2-EHA copolymer. I ths paper, a ew profle cotrol aget fabrcated by AM ad 2- EHA was sytheszed by free radcal copolymerzato. Reactvty rato[5-7], whch s a mportat parameter for free radcal copolymerzato, was also optmzed. The moomer reactvty rato ca be calculated by Q-e scheme[8, 9] from some hadbooks but t s ot uversal costats decded by the speces of radcal ad moomer. The moomer reactvty rato s also affected by the evromet such as polymerzato temperature, solvet, polarty, calculato method ad so o. Hece, the results wll be qute dfferet. I ths paper, AM/2-EHA copolymer was sytheszed wth vared AM-2-EHA feedg molar ratos ad the moomer coverso s less tha 10 wt %. Copolymer composto was determed by FT-IR method. The reactvty ratos of AM ad 2- EHA were calculated usg Yezrelev-Brokha- Rosk (YBR) calculatve method [10, 11]. The * To whom all correspodece should be set: E-malxuyogju18@6.com effect of temperature o the moomer reactvty ratos was also dscussed. Due to the calculatos of reactvty ratos at dfferet temperature, the relatos betwee the moomer reactvty ratos ad temperature were also obtaed respectvely. Ths was beefcal to dustral producto mass. MATERIAL AND METHOD Materals Moomer. Acrylamde (AM) ad 2-Ethylhexyl acrylate(2-eha); Itator. Bezoyl Peroxde (BPO); Solvet. Ethyl Alcohol ad Ethyl Acetate. AM (99.9%) ad 2-EHA (99.9%) were used for the copolymerzato wthout ay purfcato. All the solvets were freshly dstlled before use. Bezoyl peroxde (BPO, 99%) was recrystallzed from the chloroform soluto. Preparato of AM/2-EHA copolymer AM/2-EHA copolymer was prepared usg a soluto polymerzato techque as follows: AM ad 2-EHA, 20g; BPO, 0.4 mol% of total moomers; ad solvets ethyl alcohol ad ethyl acetate, 50 ml respectvely, were mxed a four- ecked flask uder a troge atmosphere. The reacto mxture was strred at 60 C. The four-ecked flask was equpped wth a cetgrade thermometer ad a water codeser ad placed a thermostat whch was mataed at the desred temperature. Termato of free radcal cha took place a costat temperature bath (0 C). The moomer coverso s less tha 10 wt % weght. The reacto mxtures, after polymerzato, were poured to a excess of

2 M. Ta, Y.J. Xu: Preparato of acrylamde/2-ethylhexyl acrylate copolymer ad calculato of moomer reactvty ratos ethyl alcohol to precptate out the product. The product was Soxhlet-extracted wth water to remove polyacrylamde. The copolymer was dred vacuo overght at room temperature to a costat weght ad used for characterzato ad moolayer studes. Characterzato of AM/2-EHA copolymer Fourer trasforms frared spectroscopy (FT- IR)Fourer trasform frared spectra recorded o a Perk-Elmer frared spectrometer usg KBr pellets. The spectra were collected over a rage of cm -1 ad each sample was measured for thrce. 13 C-NMR 13 C-NMRspectra were ru o a Bruker 400 MHz spectrometer usg bezee ad CDCl 3 as solvets. It allows the detfcato of carbo atoms a orgac molecule. The calculato of moomer reactvty ratos The stadard samples were prepared by AM ad 2-EHA homopolymers at dfferet molar rato of two moomers. The reacto codtos of AM homopolymer ad 2-EHA homopolymer are the same as that of copolymer. The bled samples were prepared to 20 wt % toluee soluto.the soluto samples were tested coatg method by FT-IR at the same spectral slt wdth. FT-IR spectra of bled samples sythetzed at 60 C was show Fg.1(b). The absorpto of C-N ad C-O-C were the characterstc peaks of AM ad 2-EHA respectvely ad the relatve peak areas were obtaed. The stadard curve was plotted betwee the bled rato ad the peak area rato of the characterstc absorpto crests, see Fg.2. The copolymer samples were prepared to 20 wt% toluee soluto the same way. The soluto samples were tested coatg method by FT-IR at the same spectral slt wdth ad the peak area rato of the characterstc absorpto crests was obtaed respectvely. The molar rato of two moomers the copolymer was ascertaed by the stadard curve. RESULTS AND DISCUSSION FT-IR aalyss The FT-IR spectrum of copolymer was show Fg.1(a).The absorpto bad at 2872 cm -1 ad 2962 cm -1 were due to symmetrcal ad atsymmetrcal stretchg vbrato of C-H prmary alkyl. Fg.1. Characterzato of Copolymer ad Homopolymer bleds.(a) FT-IR spectra of Copolymer ad Homopolymer bleds;(b) FT-IR spectra of Copolymer ad Homopolymer bleds; (c) The 13 C NMR of Copolymer. The absorpto bad at 2854 cm -1 ad 2931 cm -1 were due to symmetrcal ad atsymmetrcal stretchg vbrato of C-H secodary alkyl. The absorpto bad at 2885 cm -1 was assged to symmetrcal stretchg vbrato of C-H tertary alkyl. The absorpto bad at 1375 cm -1 ad 1460 cm -1 were due to symmetrcal ad atsymmetrcal bedg vbrato of C-H prmary alkyl. The absorpto bad at 53 cm -1 was assged to bedg vbrato of C-C alkyl. The absorpto bad at 3192 cm -1 ad 3346 cm -1 were due to symmetrcal ad atsymmetrcal stretchg vbrato of N-H (CO)NH 2. The absorpto bad at 1659 cm -1 was assged to stretchg vbrato of 75

3 M. Ta, Y.J. Xu: Preparato of acrylamde/2-ethylhexyl acrylate copolymer ad calculato of moomer reactvty ratos C=O (CO)NH 2. The absorpto bad at 1625 cm - 1 was assged to bedg vbrato of C-N (CO)NH 2. The absorpto bad at 1408 cm -1 was assged to stretchg vbrato of C-N (CO)NH 2. The absorpto bad at 807 cm -1 was assged to bedg vbrato of N-H (CO)NH 2. The absorpto bad at 1737 cm -1 was assged to stretchg vbrato of C=O R 1(CO)OR 2. The absorpto bad at 1056 cm -1 ad 1186 cm -1 were due to symmetrcal ad atsymmetrcal stretchg vbrato of C-O-C R 1(CO)OR 2. The absorpto bad at 3465 cm -1 was assged to stretchg vbrato of C=O overtoes absorpto peak R 1(CO)OR 2. There s o absorpto peak at 3100 cm -1 ~3000 cm -1 of C-H double bods. Cosequetly, AM ad 2-EHA had reacted completely ad AM/2-EHA copolymer had bee prepared. 13 C-NMR aalyss The 13 C-NMRspectrum of copolymer was show Fg.1 (c). Sgals due to the carbos of log alkyl sde chas were observed the rego ppm. The sgal at 175 ppm s due to ester carboyl carbo. The sgal at 169 ppm s due to Amde Groups. There was oly oe sgal (at δ=9) whe δ was betwee100 ad150 ad we could fer that double bods had reacted completely. The results of 13 C- NMRshowed that AM ad 2-EHA were copolymerzato. The calculato of moomer reactvty ratos The stadard samples ad the copolymer samples were prepared at 60 C respectvely. The stadard samples were prepared by AM homopolymer ad 2-EHA homopolymer at dfferet molar rato. The bled samples were prepared to 20 Table 1. The copolymer compostos at dfferet temperatures* R wt% toluee soluto. The soluto samples were tested coatg method by FT-IR (see Fg.1 (c)). The absorpto of C-N (1408cm -1 ) ad C-O-C (1056 cm -1 ) were the characterstc peaks of AM ad 2- EHA respectvely, ad the relatve peak areas A 1/A 2 were obtaed (see Fg. 2). To mmze devato the data Table 1 were treated by least square method. The stadard curve ca be obtaed, see Fg. 2. The copolymer samples were prepared to 20 wt % toluee soluto. The soluto samples were tested coatg method by FT-IR ad the peak area rato of the characterstc absorpto crests was obtaed respectvely. The molar rato of two moomers the copolymer were ascertaed by the stadard curve, see Table 1. The moomer reactvty ratos of AM ad 2-EHA were calculated by YBR calculatve method. R stads the mole fracto of AM to 2-EHA feed, ρ stads the mole fracto of AM to 2-EHA copolymer, r 1 ad r 2 are the reactvty rato of two moomers. Fg.2. The Stadard Curve K K K K K ρ Y ρ Y ρ Y ρ Y ρ Y *Y s Yeld ad the ut s % 76

4 M. Ta, Y.J. Xu: Preparato of acrylamde/2-ethylhexyl acrylate copolymer ad calculato of moomer reactvty ratos Table 2. The relatve data for the calculato of r 1 ad r 2. ** T/K T /K r 1 r 1 r 1* r 1 * E a A r 2 r 2 r 2* r 2 * E b B AVG **r1,r1, r2 adr2 are the moomer reactvty ratos of AM ad 2-EHA calculated by YBR method whle r1*,r1 *, r2* adr2 * are the moomer reactvty ratos of AM ad 2-EHA by regresso treatmet. The FR method ca be expressed by the followg: ρ=r(r 1 R+1)/( r 2 +R), (1) YBR method s the combato of FR equato ad least square method. For stace, eq (1) s multpled by R -1 ρ -1/2 to gve the followg []: (R/ρ 1/2 )r 1-(ρ 1/2 / R) r 2+(1/ρ 1/2 -ρ 1/2 )=0, (2) Takg to accout least square method, eq (3) s gve by: A 2 Ad Where, 1 r 1A 1-r 2=B 1, (3) -r 1+r 2A 2=B 2, (4) 2 A R, 1 B ( 1 R R expermetal data. Cosequetly, 2 ) R (1 ) 1, B ;: the umber of r 1=(A 2B 1+B 2)/(A 1A 2-2 ), (5) r 2=(A 1B 2+B 1)/(A 1A 2-2 ), (6) Eq (5) ad eq (6) are the YBR method. Accordgly, reactvty ratos of AM ad 2-EHA are ad respectvely. The effect of temperature o the moomer reactvty ratos The reactvty rato s defed as : r 1=k 11/k, (7), ad wth Arrheus equato defed as: k A e E11 (8.314 T ) 11 11, (8) E (8.314 T ), (9) k A e Aother form of equato (7) s: ( E11 E ) (8.314 T ) a (8.314 ) E T r k k A A e A e, (10) Where, A A11 A, Ea E11 E, A 11 A are collso factor, E 11 s the actvato eergy of cha propagato reacto self-polymerzato whle E s the actvato eergy of cha propagato reacto copolymerzato. Whe r 1 s less tha 1, k 11 s less tha k ad E 11 s more tha E. Whe r 1 s more tha 1, k 11 s more tha k ad E 11 s less tha E. r 2 ca also be obtaed as: ( ) (8.314 ) b (8.314 ) E E T E T r k k A A e B e,(11) Where, B B21 B, 22 Eb E21 E22 The moomer reactvty ratos were calculated by YBR method at 50, 60, 70, 80, 90 C respectvely, ad the composto feed was show Table 1. As the results show Table 2, the moomer reactvty ratos crease as temperature goes up, but oly a lttle. Each two sets of data treated by least square method was used to calculate the equatos of r 1 ad r 2 by Eq (10) ad Eq (11). The relatve data for the calculato of r 1 ad r 2 was show Table 2. r 1 ad r 2 ca be obtaed as: r1 ( ) e ( ) e (8.3 T r2 ( ) e ( ) e (8.314 T) T ) T 77

5 M. Ta, Y.J. Xu: Preparato of acrylamde/2-ethylhexyl acrylate copolymer ad calculato of moomer reactvty ratos DISCUSSION There s ot much dfferece betwee FT-IR spectra of AM/2-EHA copolymer ad that of the bled composed of homopolymers of AM ad 2-EHA (see Fg.1(a)). The wave umbers of absorpto peaks dd ot chage but absorpto testy chaged. The characterstc peaks homopolymer bleds behaved the same absorpto effect as that copolymer(see Fg.1(b)). As a result the stadard curve obtaed by homopolymer bleds ca be used to calculate the molar rato of two moomers the copolymer. The moomer reactvty ratos of AM ad 2-EHA are ad respectvely. It s oted that both of the moomer reactvty ratos r 1 ad r 2, eve r 1r 2, are<1, whch mples that: (1)The copolymerzato of AM ad 2-EHA s o-deal ad has azeotropc copolymerzato pot. Namely, the cocetrato of moomer soluto equals that copolymer at the azeotropc copolymerzato pot. (2) AM ad 2- EHA are proe to alteratg copolymerzato because termal groups of the copolymer ted to polymerze heterogeeous moomer,.e. alteratg copolymerzato. CONCLUSION AM/2-EHA copolymers were sytheszed by free radcal copolymerzato usg bezoyl peroxde (BPO) uder troge atmosphere at dfferet temperatures ad characterzed by FT-IR ad 13 C- NMR method. The results showed that AM ad 2- EHA were copolymerzato. The moomer reactvty ratos of AM ad 2-EHA were calculated by YBR calculatve method. The copolymer compostos were obtaed by FT-IR. The stadard curve was obtaed by homopolymer bleds ad the molar ratos of two moomers the copolymer were ascertaed by the stadard curve. The absorpto of C-N (1408cm -1 ) ad C-O-C (1056 cm -1 ) were the characterstc peaks of AM ad 2-EHA respectvely. Peak area rato of two characterstc peaks was used the calculato of the molar rato of two moomers the copolymer ad homopolymer bleds. The reactvty ratos of AM ad 2-EHA were calculated, by YBR method, to be ad respectvely. It ca be ferred that Radom copolymerzato occurred the copolymerzato of AM ad 2-EHA ad there are may alteratg uts the copolymer cha. The effect of temperature o the moomer reactvty ratos for AM ad 2-EHA was also dscussed. As temperature goes up, the moomer reactvty ratos crease, but oly a lttle. The relatos betwee r 1, r 2 ad T were also obtaed respectvely. It s smple ad relable to calculate the moomer reactvty ratos for AM ad 2-EHA free radcal copolymerzato by FT-IR spectroscopy. The method ca be used to calculate the moomer reactvty ratos whch have the separate characterstc peaks the copolymer. The moomer reactvty ratos ca be a sgfcat quattatve referece for dustral producto. REFERENCES 1. J. L, T. Wu, G. Feg,GuagDog Chem. Id., 39, 53 (20). 2. C. Kag, H. Wag, C. Lu, C. Zhag,Bochem. Eg. J., 11, 197 (2002). 3. M. Ta, Y.J. Xu,Adv. Mater. Res., , 732 (2013). 4. D. A. Z. Wever, F. Pccho, A. A. Broekhus,Id. Eg. Chem. Res., 52, (2013). 5. D. A. Z. Wever, F. Pccho, A. A. Broekhus,Prog. Polym. Sc., 36, 1558 (2011). 6. N. Pekel, N. Şaher, O. Güve, Z. M.O. Rzaev,Eur. Polym. J., 37, 2443 (2001). 7. F. M. Lews, C. Wallg, W. Cummgs, E. R. Brggs, F. R. Mayo,J. Am. Chem. Soc., 70, 1519 (1948). 8. R. Chujo, H. Ubara, A. Nshoka,Polym. J., 3, 670 (1972). 9. K. Naryosh, T.Tej, F. Juj,Bull. Chem. Soc. Jp., 36, 905 (1963) T. Sumyosh, W. Schabel,Macromol. Chem. ad Phys.,186, 1811 (1985). 11. M. Lartey, M.Gllsse, B.J. Adzma, K. Takzawa, D. R. Luebke, H. B. Nulwala,J. Polym. Sc. Pol. Chem., 51, 3359 (2013).. A. O. Moughto, T. Sagawa, W. M. Gramlch, M. Seo, T. P. Lodge, M. A.Hllmyer,Polym. Chem., Polym. Chem., 4, 166 (2013). 13. A. J. Yezrelev, E. L. Brokha,Vys. Soed., A11, 1670 (1969). 78