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Molecular mass distribution of polystyrene obtained using Li-organic compounds in benzene
P~.)l,,,n'.'r ~.~erl~.;" LI S S R Vol 27, Nu 6, pp 14fi7-1472. I~lt'~ Ptmled in P~,lana
0012- 19S018~ $10 00 ,t. O0 Pergamon JournaJ~ Lid,
MOLECULAR MASS DISTRIBUTION OF POLYST~qREr~E OBTAINED USING Li-ORGANIC COM])OI.rNDS IN BENZENE* M
A. YE'RE,'MINA,YE". G . ERBNBI.IRG, V. N. ZGONNIK, YE. YU. ME~L.ENE".VSKAYA, YEN
L,E.VBNGAGE'N a n d R. I. PAt '('HBK
L.ehedev All I.Ini~ri Rubber Re;,ear¢'l~ In~filule
( Rcccw~'d q No~,emher 198 ~)
'The wtdlh ~1' Ihe MMD ~)1'p~lyslyren¢ oblairied ori expr~,~ure h) secondary bulyl hlhium and ohgo,,lyryl I,Ih~um m benzene at different mom.~mer and ,mhator concenlrali~,~,~ ha., been Mudled. It is sh~wn Ihaf widening c,l' Ih¢ MME) wdh rt.,,e m Ihe MM or the sample,, t'~ conrie~'led with Ihe pre,,e~'e in Ihe ,~y,..lem ,~ludied td'chain Iran,der Io Ihe monomer ~ccurrtng wilh Ihe Iranq'er com, lanl .- Ii)- '~
P(iLYMERIZATIIJN u n d e r the H|l]uence of LJ-L,rgar|~c c~mp~.~und, ~'~ con'~ldered a classical ~'xampl¢ u r plllymer|z.ation o c c u r r i n g by the m e c h a n i s m o1" " l , v e " c h a i n s a n d m u s t a c c o r d i n g l y yteld p o l y m e r s with a n a r r o w M M D . In Fact, m Ihe, last I~;w years the h t e r alur¢' ha,; featured a n u m h e r t~l'studees [ I - t l in whtch ror a high degree o1" purity o r lh¢ systems a n d good m i x i n g practically n|~modlsperse PS s a m p l e s o r extremely high M M ( , - , l O '7) were o b t a i n e d . In all the case,; desertbed T H F served as solvent a n d o h g u slyryl h t h t u m ( O S L ) us i m t i a t u r . 'The rormatic~n o1" p o l y m e r s w~th a p p r e c l a h l e width (-~r the M M D in systems w=th L t o r g a n i c mlttall~rs is usl.l:llly explaMed h~' the ill,,ll~"]:iclent purity oF the r e a c t a n t s or the h~w rate o1" tmtiatKm It was re.it p~.~ssible t~i fi~J in the liLeralur¢ a n y s y s t e m a t i c invesl l g a l t o n tll" the r e a s o n s for Ihe w t d e n i n g o r the M M D tn a n y specific p o l y r n e r , z a l t o n systems with L.~-organic mdiat()rs In the present w o r k to e l u c i d a t e the n a t u r e ol" the' s e c o n d a r y reactions l e a d i n g to the w i d e n i n g or the M M D ~-~rp o l y s t y r e n e tn a r o m a t i c s o l w n t s we invest|gaLed the M M D ul Ihe PS s a m p l e s o b t a i n e d in b e n z e n e over a wide ~nterval M M a n d c o n c e n t r a t t o n s oJ' m o n o m e r a n d iIlltlatc)r a n d ~.'OlwerSlOllS. A,, indialor wu u~,ed ~ecundary hi, l,,I hlllium ~r (.)SL :,vml-w,,tzecl with ,,eeor,dary butyl l=lh=um wtlh Ihe,, unil number 8-10 [4[. P~lymerJzall,m was cl:ht~:led al 2()" C in all scaled glass ddalomelers hr,,I vacuum tr¢aled h~ I..'l ~, . l0 '~ Pa The. c~mcer,lrahun or Ih¢ ,nihalor was e,;~t=male,,dI'rom Ihe LIV ~,peclrum Benzene and slyrene were twice reclified on a column with el:ficiency or 6(.) Ihe,orehcal plales and dried m vu,'uo wtlh talc,ned cahum hydride w=lh s,mullaneous degass,ng. Ber,z.en¢ was drted wilh a .,,olulior, ol (.)SL and slor'ed =n ampuules will= a break ',;cal. Fm.',l ch'ymngof Ih¢. styrene. wa,, hy prepolymerizahon in ber,z~tne under Ihe influence ol (JSL followed by re¢or,den,.;at,on of * Vysokomol .,,uyed. A.27. No b, 1108-1112, 1985 146'7
1468
M.A.
'Ir'E',REM]~A ¢'l ul.
benzene and slyTene ,nto Ihe ampoule. 'The monomer and ~ l v e n l were dosed m all-,,¢aled systems. "T'h¢ coue'enlralkms ~.~1'iuilialc~r and monomer were , I(I "'= and .-.0 2 m~'~le/l., respe¢lively. The" layout of fhe apparatus for polymeri~ahon ,s ,ndicaled =n Fig. I. Afler unsold~'rmg the ,nslrument for Ihe synlhests o1" PS Ir~m Ihe vacuum hne af Ihe c¢'m,~frk'fion I Ihe reacfion vessel J and amp¢~ule,s 3 and 4 were washed w=lh a sLdul,on ol Ihe mil,alor ( l O S t I= I0" ~ m~de/I ) laken ,n excess; fhe lalter was puured ba~.'k tnl~ ampoule ';
F't~.~. I. D=at.u'am Ld" polymerizahou uml. E'splaualions in texl. An amounl or imtialL~r necessary I'L~r s.ynlhe.~ls was p~.~uled o1I' rain the measuring ampoule 4 and aller freezing, il w=lh .sLfl~d carbon dioxtde ve,,~el ? and ampoule ¢ washed w=lh benzene by reconden.,,in~z. ,I rrom ampl"~ule .~ and buck-p,~uring '1"he iniltalor was diluted Io Ihe requisite c,mcenlral,cm by re~.'ondensmg benzene hLmi ampuule '~ F"~'~r'!he final d.ry,ng or styrene wtlh (.')SL ils srdulion in beuzene was Iransl'erred from ampoule 0 Io .'~ breaking the, seal and then Ihe m~m~mer was rec~.mdensed inh~ vessel 2 and ampc~ule 'p was sealed ~ff af Ih¢ conslricli~.m 8 In study ~.d' Ihe course Lfl" c.onversmn of Ihe M M D Lfl' Ihe sample~, afler mixing all Ihe c~.~mpouenl,~ ,n ve~,,,el d calculaled amuunls ol fhe mixlure were poured off' ,nl~ Ihe measuring amp~~ules .¢ (in s¢~m¢ expertmeals iusiead or one ,~f the ampoules we used a dilatl.m'zeler h~ ¢valuale Ih¢ rate, ul' poiymerizah~~n) where Ihe process was also ~.'arr=ed oul Bel'¢'~reprecipilal,.m Ld' Ihe polymer rain melhau,'~l the solul=ot= was de-acl=vated by Ihe inlroduclion ~.d lerbufvl alc~.~hol (balfles ~,;) "ll=e w=dth of fhe M M D ¢.d the .',amples was character=zed holh I'rom the. dala eft" (.;PC and Ihe. ralio A.f,./M,, delermined by ahsLdule melh~d;,, iI!., was measured by the rnelhud ol illz,ht scalier aud ,~1, by ~.~srri~melry. 'The meastLremeul~ ¢.d I=ghl .~=.aller were wtlh Ilie F'ica ¢~O,LI(X)ph~'~l~gouiodttt'u.stmeler iu verh¢ally p~.darized hl.,,hf al ) = '~,4f~ mu. The in~l.rumenl wa;, calihraled agamsl benz.ene taking Ihe value R~,,, = 22 x' I0" " c m 'The solulions and solvenls were freed ol du.,,I by pu',sage Ihr,~ughout ulfra fine hllers. The asymmetry of Ihe solvenl d,d nuI exceed 1.01 From Ihe values ~.d' M~, and Ih¢ measuremenls ol the iulrinstc visc~stfy Ir/] we con.~lrucled Ihe luriclton Iv/] = / ' ( M , , ) =n I,duene al 2¢~"C wh,ch with a c,~rrecfi~.m ~','~rIhe width o f the high molecular wetghl samples l¢~1 c¢'~rrespoads (o Ih¢ equalton I,~1 = I 4'7 :, I 0 - " / ~ . . f o . ~ . The equalmn oblamed is =n g~'~c~dag]'eemen! wdh the resulls ~'~1"olher aulhors I~Sl. The osmofic measuremenls were made wtlh the WesL'an 2~10 osmomeler ,n h'duene. The get c['u'omatot-U'ams were ~.~blatued wtlh Ihe Waters GPC-200 ch.romalot,u'uph with a svslem ¢'*1 .standard culumns of (he' I~'m I0 ~'. ILl", ILl '= aud I0 ~ ~ in Iolue'ne' at an elution rule, "... I ml/nun and ~.oncen
MMD
,,r polvslyren¢ oblained usmF.,. L.i.orgamc compuurid~ m benzene
14f~O
Iralion ol'~r~mples(O (18-0 I'~). I 0 ~ g/ml. 'T'he in'~lrumeril was cahhraled ~J!..,.am',l Ihe Waler,, ,,land
urd,,. 'T'he values ~1 the mean MM were ~.alculaled w~lh rel'erenc~.' I~ iri,.,Iruni~cnlal w~derllni..,, The I'url~.'l~¢mor in;~lrumenlal widenin~ was represenled in Ihe I~rnl or the omvulule of Ihe m~rmal (.Sau,.,!.,mn d~slr=bul~lm and exponenl while ~1'~parameler,, were round hy repeal ~.'l=rom,,hq..,.raphvof Ihe narr~,,v IYaclhon (bd'rucl~m;O laken Irom Ihe Rel ¢hr¢~maloI?.,raph. Ii Ihe ¢hr~maloI.~,ram~, o1' Ihe hdracl~;m and irJillal Iracliun did nol differ we considered Ihal Ihe hrrHI of Ihe re'~olvmL.,,¢apa~.'HV ol Itie m,,tru menl had been reached 'The ¢urve,~ oblamed de,,,crihed m pure h~rm Ihe fun~lh~n ~d m,,Irumenlal 'widen i n~.~,[q] The molecular-mass characteristics and cund~l~ons rd" ohl,u~nm!.., Ihe ~ainples studied are mdicul,ed in the'.].,able. If, wdl be seen l,hal the values M , and M,, determined hy ahsolul,e methods und l,he LIP(." reel,had well agree over the whole M M ml,erval. Smee Jl, could be assumed l,hal, I.he error of l,hc method of G P(.-' is s(~mewha{ less on rletermmin!_,. l,heir rallo values are used in the '.].,able and Figures The resull,s unduuhl,edly point to lhe presence in the sv;,tem sl,udied o1' translkJr r'eacl~ons since wll,h incr'euse m the calculal,ed M M (/11~ = (lll~,tlll))lll,j where mo and ,,, are the concenlral,~Lms of monomer and HHIBaI~r; itl,~ I',; [h~ m ~ l e c u l a r mas,, ~d" the m~m~ mer uml,) Ihe experimenl,al values o1' M, increasingly deviate From it l,owards deerea,,e so Ihal. for Ihe largest value M r ='7'x , I() ~' (sample 2'~) the ral,lo Mw/M,, is ~."~. In Fact, for values of `1.'/,:~: I() t' the proces;, becumes sltal,i~nary and I'url,her mcr'ease in ,,1,1[ dL~e,, n~l, lead to increase m M, and ,t.1,,. The polydispersity coel~oent ~1" the samples is eh~,~e to two and the M M D found I'r~m the chromatogrum,~ praclically ~.'4~rre,~p~nds [u the mosl, probable (M.T,/M,,,= I.'~) 'The hteral,ure ~1" Ihe la~t few years includes a numher ,d" l,heorel,ical mvesl~gal,~on~ o1" the M M D I'ormed as a result or different transl'er react~n,~ [10-14]. Comparison of l,he experimental dal,a with l,he results or the,~e stud~es allow,~ one I,~ p~sl,ulal,e the nature o1" l,h¢ transfer reactions l,aklnL.,,, place m the proce~,~ stiJd~ed. In parl,~cular, a number o1" ¢haracl,er~stic I~-atures d~sl,mgu~sh l,be pallerns of l,h¢ pro~: ess of l,ransl'er Io the m(~n~mer =n ¢onne~,on wil,.h the racl, that such a pro~.'~..v, eil,~,l.ll'e,., Ihe constancy of l,be ral,~o of the growl,h and transl'er rates throuL.,hout the reaction. "]"hLis, I'rom [1() I il I'olh~ws l,hat the dependence ,~1" ll..lr//ll, on /ll T, For the Iran,d'~-r reacl,=un Io the monomer =s of a linear chara~.'ler of l,he Form
A,'I~
M,r_ p + - - ( I - P ) , ~'! ,,
Ill o
where P and (I - / : ' ) are l,he probabdll,~es o1" growth and transfer reaction,,,. 'Th,l~ mak~'s ~t easy Io determine I'rum Ihe ;,lope ~.)1"l,he slraighl, I,ne the l,ransl~r c~nsl,anl, n = (I - PI'P, m other words, r~=/~Jkp, ~,, and k r are the rale constants o1" l,ransl'er and growth, respeel,wely. On l,he of,her hand, the. dependence of M,,/M, on the degree ~1" conversion has the rorm or a curve w~l,h saluratlon wtule the magn,lude I/M. falls w=lb r,se =n conversion proporl~onally to I/~ (~,r remains constant on reaching steadiness) [11, I 1,]. TThe I'uacl,=on M.,/M. = f ( M . ) also has a specific, character w=l,h a hind equal I,o 2 [I I ]. The experimental resull,s obl,a=ned are presenl,ed =n l,he form or l,he I'uncl,,ons (M~,tM.)
=.I'(MI), I/M.=f(I/~), M,,/M. =./'(,~, M.)in F'=gs. 2-5.
M. A. YBREM]NA el al.
1470
CONDirlONS EOR OB'T'AININF+ I~.)LYMERS ANt) THEIR MLIL,E,CLILAR CHARACrE,,RJST'ICS 'T'e~,I No. I
2 4 6 7 8
q !(1 II 12 13 14 16'(100) 16*(19)
16+(20) 17'(ItX1) I 7q40) 18 2O 21 22 23 24*(ItK)) 24*(t0) 25'(100) 2~*(2~) 2~+(40) 25+('~1))
A'I. ,, I0" + n o :. I O 4,
Illo ,
mole/I
mole]l
1794) 81.7 h6.8 2'7.'i 24 '~ It, '~ 14 '7 112
0 88 0 h8 t) 9h 0 81) 11tJb 0 '7'-~ 1.12 0.97 101 I 0t l) 4h 0'4~ O.qo
I I 2
I0.~ 17 27 17
osmo
met r v 51 87 15 I(1 41 50 79 90 qh 11)2
70 I 1t7 220 '~1.0 4.t.0 108 -
lot)
129
171 '2'7t1
02 02 02 02 02
("1.16 OIh 0 lh 017 0 17
("12 I0 14)
0.18 1,00 I OO (),1~ 0 17 2 O0 2 (X)
~I~ I040 1 40 I '~0 2520 5200
I ~0
78(X)
(3 PC
78 52
M.,
I=ght m.'atlcr
t) 07 04 ("14 02 I)2 02 0.2
II~()
I M) I '~1)
GPC
5.1
'~2
7 1
8,0
1'~2 22.0 t1,0 18 ? 126 I1)~
107 82
14~ 24 .S t15 ~11,11) I10 96 118 Xh
116 Ill
140 180
I 12
~12 302 4.1'7
111 49'7 51'111 7LX)
14 5 It~ 2q 0 I'~ t) III ~+
121)
90 iti 4'75 74O hh
120 424 225
8X~
5qi) 286 9t)O
("1 I
It)" +
7'~ _
5 ~0
710 '~'70 9iX.) -
lit)()
0 R) 5, 26 408 009 7h 81q 171
910 I OhO 1220 I ~7';
12 R)
1~8 ~0 2~I) 81h 1112 85h h08 I ;,hO
2'7 I0 i 540 h25 2250 I qO0 261.1f) '~(X)O
2144 1607 58~ 22~0 2080 2~1~ 28,40
Mw (GPC)
IUO 101 105 112 I O7 I 09 I.I1 I t)q I 08 I. I0 1'12 I 17 I'b2 I ~,~1 I 70 I. I0 1.15 I~1 1.15
Mr M. 98 I'll I '08
,0
1.02
1'40 1.4<.I 0 72 O.q7 088 112 I 02
I 90
2 09
I f~2
1'78 I'~ I ,19 2 23 2'81 I'qh 1'~6 2 42 I t~O 2 0,t 2 0,4
i'48 I 08 25~ 257 3 26
X 40
+, tn Ihl' e~pl'nmenVJ m,trk¢,:l b y ,Jn ,J,; i'll%It Ih¢. /J;llXlpl¢% wl'rl' luhea dlJrlrlg thl' (.llUl,se ol IJse pr,xl',~s; thl' BUEll'lab, 'fl ThJrt'BIJ'll'ql'q l.'l.IFl~%pl)O4 'I it) l h e I.I)QVI.'I'IIIH1 .+ i II'I¢' m l m o r r l e r ,J++ u pl'l~.-l'BlaRe +Jl whl~.'h ll'ie ,+ample., wl'r+' l,Jkl'a Io Billet l'~Ir,erlml'nL~ m . n o m e r
('onvl'pdon
100%
T h e c o n t i n u o u s line,,+ in Fig~+. "1,-5 represent the t h e o r e t i c a l r u n c h o n s for the process .of t r a n s f e r to Ihe m o n o m e r . It will be seen that Ihe general c h a r a c t e r o f the f u n c t i o n s in all cases c o r r e s p o n d s Io the p r e d i c t i o n s o f t h e o r y . 'The value o1" the c o n s t a n t o f t r a n s f e r d e t e r m i n e d f r o m Lhe ,slope o r the s l r a i g h t line in Fig. 2 was 10 -4
'The p o i n t s in Fig. 3 s a t m f a c l o r i l y fit the t h e o r e t i c a l c u r v e [10, 121 at a = 1.3 ,: I0 -4 F o r the s a m e v a l u e o r Ihe c o n s t a n t and the values o f M.r c o r r e s p o n d i n g to the e x p e r i m e n t s 16, 17, 24 and 25 we c a l c u l a t e d the c u r v e s m Figs. 4 a n d 5. T h u s , t h e v a l u e s o f the
MMD
o1' po ystyren¢ obtairied using L,i organic ~.'ompounds in benzene
t,/,,,/t../,.,
1,471
,..,
n ,Inn -
0
,p
(3
O
'", ,, d' i
I.)
15 ,r
I
I
I
~, si
,'i
1 s Mr,li~ "~r
I0 t
Fi,;
F,,'i~j 2,
initiah~r ratio,
FiG 2. R e l a l i o n belween e x p e r i m e n l a l l y I o u n d M . and intlial munorner Ft,;
1 Wtdlh ol
MMD
us a I'uncllOn t~,l' M,,. PolnlS-¢~.pertrncnl; ~.'u~rthnuous Ilne-lhec~rellc;.ll ~.'ulve for Iransler 1o m o n o m e r at r~= I 3 , I O
I',,,, /1'I,7 I
.-
, /,.
Mr,' I9 '~
I IIz
,"
I~
c) ?#
I
2,q
[]
Iq
I
,¢--
I ,~'t
, ~
,,; FiG 4
I
/o //~
/
~
~ ~ - ~'';'~" I/ 2,'i
/
"
~ I
I
/J 75
L .
.r,
Fin. '~
F if, ,4. M.,, a,~, 1.1 funclton or ¢(mverslcm P o l n l S - e x p e r t m e n l , conltntJoUS linen ,.'aleulaled Ior Iransler Io m o n o m e r al o'= I , ' t . I0 "'t arid /if, = 8 6 , , l0 s ( I ) and '78,, 10" (2), b ro ke n c u r v ¢ - t f | c o r e l l e a l I'unehon for la"ansre, r to solvenl FIG. ", W i d l h of M M D as a I'unchon o f conver,",ion for sample,',, 16, I 7, 24 aJld 2%. Points - e x p e r i m e n t ; ¢orlllnUOlJ',i c u r v e s - Ihcoretieal funqllOg for LranM'er In m o n o m e r at a = 1.3 ~. 10-"' and M r = 8't, :,,: ,, I()" (I), ¢12 ,. 10 '~ (2), and 78 , 10 ~ ( t); b r o k e n curve, e, (4, '~'), Iheorehu'al I'uncliCm',; Ior Iran,,d'er t o solve, nl.
14'72
M.A. Y~R~M1NA el u/.
transfer c o n s t a n t s calculated from the various experimental data on the a s s u m p l t o n o f transfer to the m o n o m e r also proved to be quite ch.)se. F o r compar=son m F=gs. 4 and 5 the broken curves represent the cases o l ' s p o n l a n e t m s transfer [I 31 characteristic o f which is a c o n t i n u o u s l'all in the growth rate I\~r a c o n s t a n t transfer rate (evrdently this c n n d t h o n is also valid fur the case o f transfer Io the solvent). T h e ratio of the growth and transfer rales is so chosen that the curves match for low c o n versions and the values,~l" MT are the same as rn the curves I and 3 respechvely. 'Thus, tt may a p p a r e n t l y be taken as proven that the mare cause o f widening o f the M M D in the system studmd rs transfer to the m o n o m e r with the transfer c o n s t a n t (I .()-1.3),. I()-4 However, it must again be emphasized that the same patterns wtll be observed for any process m which the r a h o o f the growth and transfer rates remain constant. It .should also be noted that m some cases the deviations o f the e x p e r i m e n t a l M M values from t h e c a l c u l a t e d exceed the experimental errors. 'Thus, the data I'~r all the specimens nf samples 2.", s o m e w h a t differ from the calculated curves, the scalier o f the points m Fig. 3 is c o n s i d e r a b l e and the width o f the M M D ~1" the samples 22, 2~, 25-I()(J, overstated although their n u m b e r average M M s corre.,,pond In the straighl hne in Fig. 2. T h e widening o f Ihe M M D because o f Ihe high values o f M,,, may be e x p l a m e d by Ihe Iransfer reactions Io the p o l y m e r manifest for h~gh molecular weight samples o b tained at low concentration.,., o f initiator and m o n ~ m e r , i.e. m c o n d i t i o n s o f slowly progressing polymerization. 'Dan,vhlted bl' A. CRazY
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8. J. M. G. ("(.)WIE, D. J. WORSFORD and S. BYWATER, Tram, F'aradav Sl~c. 57; '70'~, Iq61 q. L. M. TERENT'EVA, Ye. G. ERENBURG, G. G. KARTASHEVA and I. Ya. PI.)DDtlBNTI, 'Tee. dokl. II Vse,,ovuz ,,imp po zhidko.~lnui khr~malograhi (SIJITIITI Rep~rl,, lind All Urnon. Symp on L,iquid Chromalog, raphv) O I K h F Akad. NaLik SSSR, Chernogulovka, Iq482 It). M. U T T a n d M. SZWARC', J Polymer Set 42: I'~#, I~#h(.) I I. V. S. N A N D A and S. C. J A I N , E.urop. Polymer J. 6: 10(.)'~, 1970 ]2 V.S. NANDA, Tram,. Faraday Sac O0: 94'-J, I*-~h,-I
l1 S . C . J A I N a n d V.S. NANDA0 Europ Polymer J 13: 13'7, 1~#77 14. 3. LARGO CABRERIZO and J. GUZMAN, Macromolecule,~ IZ: 526, 1979
0012- 19S018~ $10 00 ,t. O0 Pergamon JournaJ~ Lid,
MOLECULAR MASS DISTRIBUTION OF POLYST~qREr~E OBTAINED USING Li-ORGANIC COM])OI.rNDS IN BENZENE* M
A. YE'RE,'MINA,YE". G . ERBNBI.IRG, V. N. ZGONNIK, YE. YU. ME~L.ENE".VSKAYA, YEN
L,E.VBNGAGE'N a n d R. I. PAt '('HBK
L.ehedev All I.Ini~ri Rubber Re;,ear¢'l~ In~filule
( Rcccw~'d q No~,emher 198 ~)
'The wtdlh ~1' Ihe MMD ~)1'p~lyslyren¢ oblairied ori expr~,~ure h) secondary bulyl hlhium and ohgo,,lyryl I,Ih~um m benzene at different mom.~mer and ,mhator concenlrali~,~,~ ha., been Mudled. It is sh~wn Ihaf widening c,l' Ih¢ MME) wdh rt.,,e m Ihe MM or the sample,, t'~ conrie~'led with Ihe pre,,e~'e in Ihe ,~y,..lem ,~ludied td'chain Iran,der Io Ihe monomer ~ccurrtng wilh Ihe Iranq'er com, lanl .- Ii)- '~
P(iLYMERIZATIIJN u n d e r the H|l]uence of LJ-L,rgar|~c c~mp~.~und, ~'~ con'~ldered a classical ~'xampl¢ u r plllymer|z.ation o c c u r r i n g by the m e c h a n i s m o1" " l , v e " c h a i n s a n d m u s t a c c o r d i n g l y yteld p o l y m e r s with a n a r r o w M M D . In Fact, m Ihe, last I~;w years the h t e r alur¢' ha,; featured a n u m h e r t~l'studees [ I - t l in whtch ror a high degree o1" purity o r lh¢ systems a n d good m i x i n g practically n|~modlsperse PS s a m p l e s o r extremely high M M ( , - , l O '7) were o b t a i n e d . In all the case,; desertbed T H F served as solvent a n d o h g u slyryl h t h t u m ( O S L ) us i m t i a t u r . 'The rormatic~n o1" p o l y m e r s w~th a p p r e c l a h l e width (-~r the M M D in systems w=th L t o r g a n i c mlttall~rs is usl.l:llly explaMed h~' the ill,,ll~"]:iclent purity oF the r e a c t a n t s or the h~w rate o1" tmtiatKm It was re.it p~.~ssible t~i fi~J in the liLeralur¢ a n y s y s t e m a t i c invesl l g a l t o n tll" the r e a s o n s for Ihe w t d e n i n g o r the M M D tn a n y specific p o l y r n e r , z a l t o n systems with L.~-organic mdiat()rs In the present w o r k to e l u c i d a t e the n a t u r e ol" the' s e c o n d a r y reactions l e a d i n g to the w i d e n i n g or the M M D ~-~rp o l y s t y r e n e tn a r o m a t i c s o l w n t s we invest|gaLed the M M D ul Ihe PS s a m p l e s o b t a i n e d in b e n z e n e over a wide ~nterval M M a n d c o n c e n t r a t t o n s oJ' m o n o m e r a n d iIlltlatc)r a n d ~.'OlwerSlOllS. A,, indialor wu u~,ed ~ecundary hi, l,,I hlllium ~r (.)SL :,vml-w,,tzecl with ,,eeor,dary butyl l=lh=um wtlh Ihe,, unil number 8-10 [4[. P~lymerJzall,m was cl:ht~:led al 2()" C in all scaled glass ddalomelers hr,,I vacuum tr¢aled h~ I..'l ~, . l0 '~ Pa The. c~mcer,lrahun or Ih¢ ,nihalor was e,;~t=male,,dI'rom Ihe LIV ~,peclrum Benzene and slyrene were twice reclified on a column with el:ficiency or 6(.) Ihe,orehcal plales and dried m vu,'uo wtlh talc,ned cahum hydride w=lh s,mullaneous degass,ng. Ber,z.en¢ was drted wilh a .,,olulior, ol (.)SL and slor'ed =n ampuules will= a break ',;cal. Fm.',l ch'ymngof Ih¢. styrene. wa,, hy prepolymerizahon in ber,z~tne under Ihe influence ol (JSL followed by re¢or,den,.;at,on of * Vysokomol .,,uyed. A.27. No b, 1108-1112, 1985 146'7
1468
M.A.
'Ir'E',REM]~A ¢'l ul.
benzene and slyTene ,nto Ihe ampoule. 'The monomer and ~ l v e n l were dosed m all-,,¢aled systems. "T'h¢ coue'enlralkms ~.~1'iuilialc~r and monomer were , I(I "'= and .-.0 2 m~'~le/l., respe¢lively. The" layout of fhe apparatus for polymeri~ahon ,s ,ndicaled =n Fig. I. Afler unsold~'rmg the ,nslrument for Ihe synlhests o1" PS Ir~m Ihe vacuum hne af Ihe c¢'m,~frk'fion I Ihe reacfion vessel J and amp¢~ule,s 3 and 4 were washed w=lh a sLdul,on ol Ihe mil,alor ( l O S t I= I0" ~ m~de/I ) laken ,n excess; fhe lalter was puured ba~.'k tnl~ ampoule ';
F't~.~. I. D=at.u'am Ld" polymerizahou uml. E'splaualions in texl. An amounl or imtialL~r necessary I'L~r s.ynlhe.~ls was p~.~uled o1I' rain the measuring ampoule 4 and aller freezing, il w=lh .sLfl~d carbon dioxtde ve,,~el ? and ampoule ¢ washed w=lh benzene by reconden.,,in~z. ,I rrom ampl"~ule .~ and buck-p,~uring '1"he iniltalor was diluted Io Ihe requisite c,mcenlral,cm by re~.'ondensmg benzene hLmi ampuule '~ F"~'~r'!he final d.ry,ng or styrene wtlh (.')SL ils srdulion in beuzene was Iransl'erred from ampoule 0 Io .'~ breaking the, seal and then Ihe m~m~mer was rec~.mdensed inh~ vessel 2 and ampc~ule 'p was sealed ~ff af Ih¢ conslricli~.m 8 In study ~.d' Ihe course Lfl" c.onversmn of Ihe M M D Lfl' Ihe sample~, afler mixing all Ihe c~.~mpouenl,~ ,n ve~,,,el d calculaled amuunls ol fhe mixlure were poured off' ,nl~ Ihe measuring amp~~ules .¢ (in s¢~m¢ expertmeals iusiead or one ,~f the ampoules we used a dilatl.m'zeler h~ ¢valuale Ih¢ rate, ul' poiymerizah~~n) where Ihe process was also ~.'arr=ed oul Bel'¢'~reprecipilal,.m Ld' Ihe polymer rain melhau,'~l the solul=ot= was de-acl=vated by Ihe inlroduclion ~.d lerbufvl alc~.~hol (balfles ~,;) "ll=e w=dth of fhe M M D ¢.d the .',amples was character=zed holh I'rom the. dala eft" (.;PC and Ihe. ralio A.f,./M,, delermined by ahsLdule melh~d;,, iI!., was measured by the rnelhud ol illz,ht scalier aud ,~1, by ~.~srri~melry. 'The meastLremeul~ ¢.d I=ghl .~=.aller were wtlh Ilie F'ica ¢~O,LI(X)ph~'~l~gouiodttt'u.stmeler iu verh¢ally p~.darized hl.,,hf al ) = '~,4f~ mu. The in~l.rumenl wa;, calihraled agamsl benz.ene taking Ihe value R~,,, = 22 x' I0" " c m 'The solulions and solvenls were freed ol du.,,I by pu',sage Ihr,~ughout ulfra fine hllers. The asymmetry of Ihe solvenl d,d nuI exceed 1.01 From Ihe values ~.d' M~, and Ih¢ measuremenls ol the iulrinstc visc~stfy Ir/] we con.~lrucled Ihe luriclton Iv/] = / ' ( M , , ) =n I,duene al 2¢~"C wh,ch with a c,~rrecfi~.m ~','~rIhe width o f the high molecular wetghl samples l¢~1 c¢'~rrespoads (o Ih¢ equalton I,~1 = I 4'7 :, I 0 - " / ~ . . f o . ~ . The equalmn oblamed is =n g~'~c~dag]'eemen! wdh the resulls ~'~1"olher aulhors I~Sl. The osmofic measuremenls were made wtlh the WesL'an 2~10 osmomeler ,n h'duene. The get c['u'omatot-U'ams were ~.~blatued wtlh Ihe Waters GPC-200 ch.romalot,u'uph with a svslem ¢'*1 .standard culumns of (he' I~'m I0 ~'. ILl", ILl '= aud I0 ~ ~ in Iolue'ne' at an elution rule, "... I ml/nun and ~.oncen
MMD
,,r polvslyren¢ oblained usmF.,. L.i.orgamc compuurid~ m benzene
14f~O
Iralion ol'~r~mples(O (18-0 I'~). I 0 ~ g/ml. 'T'he in'~lrumeril was cahhraled ~J!..,.am',l Ihe Waler,, ,,land
urd,,. 'T'he values ~1 the mean MM were ~.alculaled w~lh rel'erenc~.' I~ iri,.,Iruni~cnlal w~derllni..,, The I'url~.'l~¢mor in;~lrumenlal widenin~ was represenled in Ihe I~rnl or the omvulule of Ihe m~rmal (.Sau,.,!.,mn d~slr=bul~lm and exponenl while ~1'~parameler,, were round hy repeal ~.'l=rom,,hq..,.raphvof Ihe narr~,,v IYaclhon (bd'rucl~m;O laken Irom Ihe Rel ¢hr¢~maloI?.,raph. Ii Ihe ¢hr~maloI.~,ram~, o1' Ihe hdracl~;m and irJillal Iracliun did nol differ we considered Ihal Ihe hrrHI of Ihe re'~olvmL.,,¢apa~.'HV ol Itie m,,tru menl had been reached 'The ¢urve,~ oblamed de,,,crihed m pure h~rm Ihe fun~lh~n ~d m,,Irumenlal 'widen i n~.~,[q] The molecular-mass characteristics and cund~l~ons rd" ohl,u~nm!.., Ihe ~ainples studied are mdicul,ed in the'.].,able. If, wdl be seen l,hal the values M , and M,, determined hy ahsolul,e methods und l,he LIP(." reel,had well agree over the whole M M ml,erval. Smee Jl, could be assumed l,hal, I.he error of l,hc method of G P(.-' is s(~mewha{ less on rletermmin!_,. l,heir rallo values are used in the '.].,able and Figures The resull,s unduuhl,edly point to lhe presence in the sv;,tem sl,udied o1' translkJr r'eacl~ons since wll,h incr'euse m the calculal,ed M M (/11~ = (lll~,tlll))lll,j where mo and ,,, are the concenlral,~Lms of monomer and HHIBaI~r; itl,~ I',; [h~ m ~ l e c u l a r mas,, ~d" the m~m~ mer uml,) Ihe experimenl,al values o1' M, increasingly deviate From it l,owards deerea,,e so Ihal. for Ihe largest value M r ='7'x , I() ~' (sample 2'~) the ral,lo Mw/M,, is ~."~. In Fact, for values of `1.'/,:~: I() t' the proces;, becumes sltal,i~nary and I'url,her mcr'ease in ,,1,1[ dL~e,, n~l, lead to increase m M, and ,t.1,,. The polydispersity coel~oent ~1" the samples is eh~,~e to two and the M M D found I'r~m the chromatogrum,~ praclically ~.'4~rre,~p~nds [u the mosl, probable (M.T,/M,,,= I.'~) 'The hteral,ure ~1" Ihe la~t few years includes a numher ,d" l,heorel,ical mvesl~gal,~on~ o1" the M M D I'ormed as a result or different transl'er react~n,~ [10-14]. Comparison of l,he experimental dal,a with l,he results or the,~e stud~es allow,~ one I,~ p~sl,ulal,e the nature o1" l,h¢ transfer reactions l,aklnL.,,, place m the proce~,~ stiJd~ed. In parl,~cular, a number o1" ¢haracl,er~stic I~-atures d~sl,mgu~sh l,be pallerns of l,h¢ pro~: ess of l,ransl'er Io the m(~n~mer =n ¢onne~,on wil,.h the racl, that such a pro~.'~..v, eil,~,l.ll'e,., Ihe constancy of l,be ral,~o of the growl,h and transl'er rates throuL.,hout the reaction. "]"hLis, I'rom [1() I il I'olh~ws l,hat the dependence ,~1" ll..lr//ll, on /ll T, For the Iran,d'~-r reacl,=un Io the monomer =s of a linear chara~.'ler of l,he Form
A,'I~
M,r_ p + - - ( I - P ) , ~'! ,,
Ill o
where P and (I - / : ' ) are l,he probabdll,~es o1" growth and transfer reaction,,,. 'Th,l~ mak~'s ~t easy Io determine I'rum Ihe ;,lope ~.)1"l,he slraighl, I,ne the l,ransl~r c~nsl,anl, n = (I - PI'P, m other words, r~=/~Jkp, ~,, and k r are the rale constants o1" l,ransl'er and growth, respeel,wely. On l,he of,her hand, the. dependence of M,,/M, on the degree ~1" conversion has the rorm or a curve w~l,h saluratlon wtule the magn,lude I/M. falls w=lb r,se =n conversion proporl~onally to I/~ (~,r remains constant on reaching steadiness) [11, I 1,]. TThe I'uacl,=on M.,/M. = f ( M . ) also has a specific, character w=l,h a hind equal I,o 2 [I I ]. The experimental resull,s obl,a=ned are presenl,ed =n l,he form or l,he I'uncl,,ons (M~,tM.)
=.I'(MI), I/M.=f(I/~), M,,/M. =./'(,~, M.)in F'=gs. 2-5.
M. A. YBREM]NA el al.
1470
CONDirlONS EOR OB'T'AININF+ I~.)LYMERS ANt) THEIR MLIL,E,CLILAR CHARACrE,,RJST'ICS 'T'e~,I No. I
2 4 6 7 8
q !(1 II 12 13 14 16'(100) 16*(19)
16+(20) 17'(ItX1) I 7q40) 18 2O 21 22 23 24*(ItK)) 24*(t0) 25'(100) 2~*(2~) 2~+(40) 25+('~1))
A'I. ,, I0" + n o :. I O 4,
Illo ,
mole/I
mole]l
1794) 81.7 h6.8 2'7.'i 24 '~ It, '~ 14 '7 112
0 88 0 h8 t) 9h 0 81) 11tJb 0 '7'-~ 1.12 0.97 101 I 0t l) 4h 0'4~ O.qo
I I 2
I0.~ 17 27 17
osmo
met r v 51 87 15 I(1 41 50 79 90 qh 11)2
70 I 1t7 220 '~1.0 4.t.0 108 -
lot)
129
171 '2'7t1
02 02 02 02 02
("1.16 OIh 0 lh 017 0 17
("12 I0 14)
0.18 1,00 I OO (),1~ 0 17 2 O0 2 (X)
~I~ I040 1 40 I '~0 2520 5200
I ~0
78(X)
(3 PC
78 52
M.,
I=ght m.'atlcr
t) 07 04 ("14 02 I)2 02 0.2
II~()
I M) I '~1)
GPC
5.1
'~2
7 1
8,0
1'~2 22.0 t1,0 18 ? 126 I1)~
107 82
14~ 24 .S t15 ~11,11) I10 96 118 Xh
116 Ill
140 180
I 12
~12 302 4.1'7
111 49'7 51'111 7LX)
14 5 It~ 2q 0 I'~ t) III ~+
121)
90 iti 4'75 74O hh
120 424 225
8X~
5qi) 286 9t)O
("1 I
It)" +
7'~ _
5 ~0
710 '~'70 9iX.) -
lit)()
0 R) 5, 26 408 009 7h 81q 171
910 I OhO 1220 I ~7';
12 R)
1~8 ~0 2~I) 81h 1112 85h h08 I ;,hO
2'7 I0 i 540 h25 2250 I qO0 261.1f) '~(X)O
2144 1607 58~ 22~0 2080 2~1~ 28,40
Mw (GPC)
IUO 101 105 112 I O7 I 09 I.I1 I t)q I 08 I. I0 1'12 I 17 I'b2 I ~,~1 I 70 I. I0 1.15 I~1 1.15
Mr M. 98 I'll I '08
,0
1.02
1'40 1.4<.I 0 72 O.q7 088 112 I 02
I 90
2 09
I f~2
1'78 I'~ I ,19 2 23 2'81 I'qh 1'~6 2 42 I t~O 2 0,t 2 0,4
i'48 I 08 25~ 257 3 26
X 40
+, tn Ihl' e~pl'nmenVJ m,trk¢,:l b y ,Jn ,J,; i'll%It Ih¢. /J;llXlpl¢% wl'rl' luhea dlJrlrlg thl' (.llUl,se ol IJse pr,xl',~s; thl' BUEll'lab, 'fl ThJrt'BIJ'll'ql'q l.'l.IFl~%pl)O4 'I it) l h e I.I)QVI.'I'IIIH1 .+ i II'I¢' m l m o r r l e r ,J++ u pl'l~.-l'BlaRe +Jl whl~.'h ll'ie ,+ample., wl'r+' l,Jkl'a Io Billet l'~Ir,erlml'nL~ m . n o m e r
('onvl'pdon
100%
T h e c o n t i n u o u s line,,+ in Fig~+. "1,-5 represent the t h e o r e t i c a l r u n c h o n s for the process .of t r a n s f e r to Ihe m o n o m e r . It will be seen that Ihe general c h a r a c t e r o f the f u n c t i o n s in all cases c o r r e s p o n d s Io the p r e d i c t i o n s o f t h e o r y . 'The value o1" the c o n s t a n t o f t r a n s f e r d e t e r m i n e d f r o m Lhe ,slope o r the s l r a i g h t line in Fig. 2 was 10 -4
'The p o i n t s in Fig. 3 s a t m f a c l o r i l y fit the t h e o r e t i c a l c u r v e [10, 121 at a = 1.3 ,: I0 -4 F o r the s a m e v a l u e o r Ihe c o n s t a n t and the values o f M.r c o r r e s p o n d i n g to the e x p e r i m e n t s 16, 17, 24 and 25 we c a l c u l a t e d the c u r v e s m Figs. 4 a n d 5. T h u s , t h e v a l u e s o f the
MMD
o1' po ystyren¢ obtairied using L,i organic ~.'ompounds in benzene
t,/,,,/t../,.,
1,471
,..,
n ,Inn -
0
,p
(3
O
'", ,, d' i
I.)
15 ,r
I
I
I
~, si
,'i
1 s Mr,li~ "~r
I0 t
Fi,;
F,,'i~j 2,
initiah~r ratio,
FiG 2. R e l a l i o n belween e x p e r i m e n l a l l y I o u n d M . and intlial munorner Ft,;
1 Wtdlh ol
MMD
us a I'uncllOn t~,l' M,,. PolnlS-¢~.pertrncnl; ~.'u~rthnuous Ilne-lhec~rellc;.ll ~.'ulve for Iransler 1o m o n o m e r at r~= I 3 , I O
I',,,, /1'I,7 I
.-
, /,.
Mr,' I9 '~
I IIz
,"
I~
c) ?#
I
2,q
[]
Iq
I
,¢--
I ,~'t
, ~
,,; FiG 4
I
/o //~
/
~
~ ~ - ~'';'~" I/ 2,'i
/
"
~ I
I
/J 75
L .
.r,
Fin. '~
F if, ,4. M.,, a,~, 1.1 funclton or ¢(mverslcm P o l n l S - e x p e r t m e n l , conltntJoUS linen ,.'aleulaled Ior Iransler Io m o n o m e r al o'= I , ' t . I0 "'t arid /if, = 8 6 , , l0 s ( I ) and '78,, 10" (2), b ro ke n c u r v ¢ - t f | c o r e l l e a l I'unehon for la"ansre, r to solvenl FIG. ", W i d l h of M M D as a I'unchon o f conver,",ion for sample,',, 16, I 7, 24 aJld 2%. Points - e x p e r i m e n t ; ¢orlllnUOlJ',i c u r v e s - Ihcoretieal funqllOg for LranM'er In m o n o m e r at a = 1.3 ~. 10-"' and M r = 8't, :,,: ,, I()" (I), ¢12 ,. 10 '~ (2), and 78 , 10 ~ ( t); b r o k e n curve, e, (4, '~'), Iheorehu'al I'uncliCm',; Ior Iran,,d'er t o solve, nl.
14'72
M.A. Y~R~M1NA el u/.
transfer c o n s t a n t s calculated from the various experimental data on the a s s u m p l t o n o f transfer to the m o n o m e r also proved to be quite ch.)se. F o r compar=son m F=gs. 4 and 5 the broken curves represent the cases o l ' s p o n l a n e t m s transfer [I 31 characteristic o f which is a c o n t i n u o u s l'all in the growth rate I\~r a c o n s t a n t transfer rate (evrdently this c n n d t h o n is also valid fur the case o f transfer Io the solvent). T h e ratio of the growth and transfer rales is so chosen that the curves match for low c o n versions and the values,~l" MT are the same as rn the curves I and 3 respechvely. 'Thus, tt may a p p a r e n t l y be taken as proven that the mare cause o f widening o f the M M D in the system studmd rs transfer to the m o n o m e r with the transfer c o n s t a n t (I .()-1.3),. I()-4 However, it must again be emphasized that the same patterns wtll be observed for any process m which the r a h o o f the growth and transfer rates remain constant. It .should also be noted that m some cases the deviations o f the e x p e r i m e n t a l M M values from t h e c a l c u l a t e d exceed the experimental errors. 'Thus, the data I'~r all the specimens nf samples 2.", s o m e w h a t differ from the calculated curves, the scalier o f the points m Fig. 3 is c o n s i d e r a b l e and the width o f the M M D ~1" the samples 22, 2~, 25-I()(J, overstated although their n u m b e r average M M s corre.,,pond In the straighl hne in Fig. 2. T h e widening o f Ihe M M D because o f Ihe high values o f M,,, may be e x p l a m e d by Ihe Iransfer reactions Io the p o l y m e r manifest for h~gh molecular weight samples o b tained at low concentration.,., o f initiator and m o n ~ m e r , i.e. m c o n d i t i o n s o f slowly progressing polymerization. 'Dan,vhlted bl' A. CRazY
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2 D. MC IN"FIRE, L. J. FETTERS and E. SLAGOWSKI, Science 176: 1041. Iq72 3. T. FtlJ1MO'rO and M. NAGASAWA, Pnlvmcr J 7: 3t~7. It~7'~ 4. ¥e. Yu. MELENEVSKAYA, V. N. ZGONNIK and K. K. KALNIN'SH, Vw,,l~nrnol :,~yed BI8: 8hq, Iq76 (Nul Iran~lalud in Polymer S~.'i. LJ S.S R.) M. KURATA, Y. TSUNASI-flMA, M. IWAMA and K. KAMADA, Pnlvmer Handb,ok, Chap IV, p .~, Wdev Inler,~ci , N Y , IqT~ O P. O U T E R , C. J. CARR and g. H. Z I M M , .I (?hem Phv,,. 8: 8t0, It~'K) '7. M. KLIRATA, H. O K A M O T ( . ) , M. I W A M A , M. ABE and T. H O M M A , Iq72
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8. J. M. G. ("(.)WIE, D. J. WORSFORD and S. BYWATER, Tram, F'aradav Sl~c. 57; '70'~, Iq61 q. L. M. TERENT'EVA, Ye. G. ERENBURG, G. G. KARTASHEVA and I. Ya. PI.)DDtlBNTI, 'Tee. dokl. II Vse,,ovuz ,,imp po zhidko.~lnui khr~malograhi (SIJITIITI Rep~rl,, lind All Urnon. Symp on L,iquid Chromalog, raphv) O I K h F Akad. NaLik SSSR, Chernogulovka, Iq482 It). M. U T T a n d M. SZWARC', J Polymer Set 42: I'~#, I~#h(.) I I. V. S. N A N D A and S. C. J A I N , E.urop. Polymer J. 6: 10(.)'~, 1970 ]2 V.S. NANDA, Tram,. Faraday Sac O0: 94'-J, I*-~h,-I
l1 S . C . J A I N a n d V.S. NANDA0 Europ Polymer J 13: 13'7, 1~#77 14. 3. LARGO CABRERIZO and J. GUZMAN, Macromolecule,~ IZ: 526, 1979