Thermal breakdown mechanism of crosslinked polymers based on diepoxides and aromatic and aliphatic amines

Thermal br~r&kdown moch~ntma of cr~,~li,tk,~i polymor~

~793

REFERENCES I. V. V. KORSHAK, V. G. DA~NLLOV, L. G. KOMAROVA, N. I. BEKASOVA and L. A.

LEITE8, Vysokomol. soyed. Al$: 1517, 1971 (TrmJslat<.d m Polymer Sei. U.S.S.R. i$: 7. 1705. 1971) 2. V. V. KORSHAK. N. I. BEKA,~OVA a~ld L. G. KOMAROVA. Vvsokom.I, s,,y~xl. Ai5: 1866, 1970 (Tran.~lat*,d in Polymer Sei. U.S.,q.R. 12: 8, 2116. 1970) 3. L. I. ZAKHARKIN and V. N. KALI~IN, l)okl. AN SSSH 16~: 1, 110. 1965, 4. B. A. KOROLEV. T. V. LEVANDOVSKAYA ~md M. V. GORELI'K, Zh. (dm||o,h. khttllit 4,8: I, 157, 1978

Polymer Scleuce I'.S.~.R. Vol. 24. No. 11. pp. 2793-2808. 19~2 Prtrded hi l',daud

DO~2- 39bO/W2 $7.30 ~- .00 ~, I0~I Pergamon l~ro~ Ltd.

THERMAL BREAKDOWN MECHANISM OF CROSSLINKED POI,YMEILq BASED ON DIEPOXIDES AND AROMATIC AND ALIPHATIC AMINES* T.

S.

ZARKII'/NA,

l,.

S.

Z A R K | I , IN,

A. N. ZFLr:.uE'rSKH. l,. V. KAx.~t~,ox'x and E. V. |'RUT

[]LSlit ,it," of Chomictd Phym(m. U.S.S.R. A,..~l..-~y of Sol,me(.-¢ ( l'¢eceitzd 4.1 ~dy 1981 )

l"i-Id ma..~-s~etromotry was ,reed to atudy th,.,'uml.d,.gradation of cr,)~link(.,d polym(.r~ ba.~d ¢,n diepoxidc~ aaid anmmtie and ~dipl.~ti(~ tmm,,a, l~suh~ w4"ro obtained al~mt the structure, and ¢'omI~mitiotl of br,-akd,~u produota av,d th,.w ,llt~e|~ilti~tn cJf f,)rmation. WE studied pr(.viously [!, 2] t h e r m a l and t h c r n m l - o x i d a t i v e b n . a k d o w n of p o l y m e r s based on diglycidyl ethers of (liphcnols a n d a r o m a t i c a m i n e s a n d low m o l e c u l a r w e i g h t c o m p o u n d s , which s i m u l a t e tile s t r u c t u r e of the~. p o l y m e r s . A c o m p a r a t i v e s t u d y was m a d e [3] o f t h e r m a l degrad~,tion of model c o m p o u n d s baee(l on a r o m a t i c a n d aliphatie a m i n e s in v a c u u m (10 t_10.5 Pa). It was s h o w n t h a t d e t e r m i n i n g b r e a k d o w n a t inerea.~ed t e m p e r a t u r e s as a p u r e l y t h e r m a l or t h e r m o - o x i d a t i v e pro(~as is conditional since b r e a k d o w n is initiated eveft in high v a c u u m ( 1 0 ~ Pa) b y hydroperoxi(tes f o r m e d during t h e s)mthesis a n d s t o r a g e of p o l y m e r s a n d model c o m p o u n d s in air. A s t u d y was ma(le in this p a p e r of t h e x m a l d e g r a d a t i o n o f a cro.~slinked p o l y m e r b a s e d on diglycidyl e t h e r of d i p h e n y l o l p r o p a n e ( I ) G E D ) a n d t r i e t h y l e n e t e t r a m i n e ( T E T A ) a n d a c o m p a r a t i v e analysis wa~ m a d e of results o b t a i n e d a n d results of t h e r m a l * Vy~okomol. soyed. A24: No. 11, 2429-2442, 1982.

2794

T . S . ZAn~m~A d a/.

d e g r a d a t i o n o f a cross!inked p o l y m e r b a s e d on diglicidyl e t h e r o f resorcinol ( D G E R ) a n d a r o m a t i c a m i n e - - m e t a - p h e n y l e n e d i a m i n e (MPDA). A crosslinked polymer based on diepoxide and arorn~tic amine [-- CHsCH(OH)CHIOROCHsCH(OH)CH~RNCH~CH(OH)CHIOROCHICH(OH)CH,--]n, I where R=ffi~n-C~I,, was obtained by the reaction o f DGER with iKPDA with a gravimetrie ratio of reagents (4.1 : 1). Conditions of hardening were as follows: 60°--2 hr, 81°--2 hr, 100° - 2 hr, cooling--natural. The maximum degree of the reaction determined by chemical titration and calorimetry was 85-900//o. The polymer was analysed using a mass-speetreme~er and vacuum thermogravimet~r and it was shown that it contained ~ 1 wt. % occluded water. The polymer contained no other impurities. A crosslinked polymer based on diepoxide and aliphatic amine

II where R'~n-CeH,, was obtained by the reaction of DGED with TETA with a gravimetrio ratio of reagents of 8 : 1. Conditions of solidification were: 100° 5 hr, cooling--natural. The degree of the reaction of epoxide with amine, determined by chemical titration was 70-75 %. Polymer samples were prepared in the form of films 100-300/~m thick. All initial products were purified by standard methods; the preparation of model compounds was described previously [1, 3]. Crosslinked polymer samples and model compounds studied were heated in a vacuum compartment of a Varian-MAT mass-spectrometer, in which field ionization was used. Experimental methods were described previously [3]. The absence of decomposition of molecular ions in field ionization was verified specially using a number of low molecular weight compounds: C6HsOCHtCH(OH)CHtNHCeH6, [C,H6OCHaCH(OH)CHB--]sNCaHs, DGED, DGER and MPDA simulating the structure of the polymers examined. Field massspectra of breakdown products were identified on the basis of information about the break. down mechanism of heavier low-molecular weight compounds which also simulate the structure of the polymers examined. During the breakdown of these compounds product pairs are formed, the total weight of which is equal to the weight of the initial compound, which clearly indicates rupture at particular bonds. The presence of similar products in Polymer breakdown suggests that the mechanisms established for model compounds are also valid for polymers. T o p r e p a r e a p o l y m e r w i t h a m a x i m u m possible degree o f crossllnklng i t is essential t o e x c l u d e diffusion control o f t h e reaction. T h e r a t e o f diffusion m a y b e i n c r e a s e d w i t h a n increase in t e m p e r a t u r e . W h e n s y n t h e s i z i n g p o l y m e r I i t w a s e s t a b l i s h e d [4] t h a t on increasing r e a c t i o n t e m p e r a t u r e f r o m 50 t o 100 ° m a x i m u m r e a c t i o n r a t e ~max increases f r o m 80 to 95%, i.e. t o a v a l u e w h i c h c o r r e s p o n d s t o t h e topological H m i t o f t h e r e a c t i o n [5, 6]. L o w v a l u e s o f ~lim ( 7 0 - 7 5 % ) d e r i v e d b y us for p o l y m e r I I are e v i d e n t l y n o t d u e t o diffusion, or topological restrictions in t h e p o l y m e r n e t w o r k f o r m e d . W e h a v e s h o w n p r e v i o u s l y [3] t h a t e v e n w h e n s y n t h e s i z i n g a m o d e l s y s t e m

Thermal breakdown meelm~ism of erosslinked polymers

279~

using phenylglycidyl ether (PGE) and ethylenediamine (EDA) (molar ratio of 4 : 1) in benzene, where diffusion and topological restrictions are excluded, tetra-substituted EDA cannot be obtained during an acceptable experimental t~ne at N20°; the end product consists mainly of di- and tri-substi~uted EDA. The cause of such inhibition of the reaction, so far, is unknown. According to a previous paper [7], unreacted epoxide groups present in polymer I I may react at increased temperatures with hydroxyl groups formed during the reaotion of epoxide with amine. Furthermore, the reaction in air at ~ 100 ° may be accompanied by slight oxidation and degradation of the polymer [2]. I n order to minimize t h e participation of secondary reactions indicated, model systems of P G E - E D A (4 : 1) a n d D G E D - E D A (1 : 2) were synthesized T~B~ 1. B~F~r~DOW~PRODUCTSOF MODELSYSTEMSBASEDO~TPGE-EDA ~ DGED-DEA PREPARED AT 70° IN AIR AND CONTAININGk ~ C H ~ C H ( - - O C H ~ ) C H ~ ~ o ~ System PGE-EDA

role

Breakdown product*

300

C6H~OCH~C= CH~

(4 : 1)

~CH2GH(OH)CHIOC6H5 CeH~OCH~C(O)CH~NCH2CHCH2C6H6

479

J

CHs 0CH2CH(OH)CH2OC6Hs C6H~OCH~C(O)CHsNCHaCHCH~OC6H6 t !

(491)

CHs=~H 6CH~CH(OH)CH,OCeH5 CeH5OCH~CH(OH)CHI\ ? N C H I C H ~ T = CHI (522) C6HsOCH,CHCH2

490-492

518-522

I

OCH~CH(OH)CH~OCaH5 DGED-DEA (I :

2)

171 185

E t ~ C H ~-CHOCH~C(O)CH3 Etsl~CHzC =CHa

elCH2C(O)CH3 Et~NCH~C = CH2 ~O (279) CH2CH(OH) CHtOC.H5 Et~NCH----CHOCH,CH(OH) CH,OCeH~C(CHa)=CH~ Et~NCH~C=CHa

I

277,279 303, 305 317,319

OCH~CH(OH) CH~0C6H~C(CHa)-----CH~ Et ~NCH2CHCH~OC6H~C(CH3)-----CHz

319, 321

~CH~CI_I(OH)CH3 Et~NCH2CHCH~OCsH5

370

(321) (371)

I

OCH,C(O)CH~OC~H~ Et~NCH~CHCH,OC~H~H~C(CH~)=CH~ ~CHtC(O)OH~OC~H,C(CH~) =CH~ * Calculated ~

i s shown in b r a c k z t ~

450

(451)

T. S. Z ~ A

2796

et ~/.

a t 20 ° in a solvent. (benzene, heptane) and in argon [8]. T o determine the effect of secondary reactions in formulating the structure of crosslinked polymer II, we obtained model systems in this study: P G E - E D A (4 : 1) and DGED-EDA (1 : 2) at 70 ° in air and compared their thermal breakdown products with break: down products of "ideal" models. It may be concluded from the comparative analysis made that among breakdown products of "non-ideal" model systems (in contrast with breakdown products of "ideal" model systems [3]), compound8 T~LE

2 . P R O D U C T S OF T H E R M A L O X I D A T t v ~

MODELSYSTEMSPGE-EDA, DGED-DEA ~

B R E A K D O W N F O R M E D B Y TH/~ S Y N T H E S I S O F

POLYMERII rr¢ Am &T r~CR]rXSED T E ~ -

TURIg8

m/e*

Product structure

18.19 (a,

HsO, H.O+ CO (28). N H = C H , (29). H , C = O (30) CH,=NCHj (43). HsNCH=CHs (43). CHzCH=O (44) C6H,OH C,HsOCHICHO CsHtOCHIC(O)CHs C6HsOCHICH(OH)CHzOH

29 (o) 43 (b,

c)

94 (a) 136 (a)

15o (a) 168 (a) 186 (a)

Oil 18s (a)

255 (a) 147 (e)

C,H6OCHaCH(OH)CH,N(CH,)CHaCH(OH)CH,OH CHsNHCHtCH2N(CHs)CHsCH(OH)CHs (146) EtNHCHICHINHCH tCH (OH) CH3 (146) H(--NHCHICHt--)sNH s (146) CHsCH(OH)CH~OC,H,C(CHs) = CHs (192) C~H6OCHaC(O)CH~(CHs) I (193) CtHsOCHaCH(OH)CHsN = CHCH 3 (193) HtNCHtCH(OH)CHiOC.H4C(CHs) =CHa (207) EtN(CHI)CHsC(O)CHtOC6H~ (207) H~NCHsCH~HCH ~C(O)CHtOC6H s (208) C,HsC(= CHI)CHsC~H,OH HOC,H,C(CHs) IC6H,OH CH=OC,H,OCeH,C(CHs) = CH~ CHsOC,H,C(CHs) IC,H4OH C,H6OCHffiCH(OH)CH~N(CH3)CHzCHsN(CHa) t CH3OC6H4C(CH~)IC,H4OCHa HzC CH~ O

\

J

C

tiO i ~ / ~ CHs

C--CH. /~/~CHs

193 (b, c) 208 (b, c)

226 (c) 228 (b, e) 240 (¢) 242 (b, c) 252 (b, o) 256 (b, c) CHz

S

C

bl c)

2797

T h e r m a l b r e a k d o w n m e c l u m i s m o f crosslinked p o l y m e r s T ~ L ~ 2 (conS.) Product structure

CH~

role*

Cells o

~H~~H~_C_~OH, ~I~s --

I

CH, CiH--Ott CH,

266 (b, e)

CH,

CH31~CH,CH. ~NEt

E%NCH,C(O)CH(OH)OC,H4C(CHa) ~ CH~ (277) (CHs)~TCH,CH~HCHsCH(OH)CH~OC6H4C(CHs) =C~H~ (278) HOC,H~C(CHs),C6H,OCH,C(O)CHs HOC6H,C(CHs)sC6H,OCHsCE(OH)CHa CHaOCsH,C(CHs)IC,H,OCHffiCHIOH

277, 278 (b, e) 284 (o) 286 (b, e)

* a--DGE-EDA system (4 : 1); b--DGED-D]~A (1 : 2); c--polym~ IT.

with a branching fragment of the hydroxypropylene chain, ~CHaCH(CH~)" •OCHzCH(OH)~, formed during the reaction of epoxide with the hydroxyl group (Table 1) (products of similar structure formed during breakdown of polymer II, are shown in Table 3 and denoted by an asterisk*) and products of thermo-oxidative breakdown (Table 2) are present in a noticeable proportion. The presence of these compounds among breakdown products proves t h a t already at the stage of synthesis of model systems and a polymer based on aliphatic amines reactions of addition of epoxide to a hydroxyl group and thermooxidative breakdown take place at a noticeable rate. In reactions of DGER with MPDA and PGE with MPDA the reaction of epoxide with a hydroxyl group has a slight effect [4]. The absence from mass° spectra of polymer I and the PGE-MPDA model system (4 : 1) of breakdown products up to temperatures of 260 and 225 °, respectively [1] suggests that thermo-oxidative breakdown does not take place in practice either during synthesis in air at 100 °, or during subsequent heating in vacuum. This is, evidently, due to the inhibiting action of aromatic amines [2]. Various temperatures at which first products of thermal degradation of PGE-MPDA model compounds (4:1) (225 °) and a DGER-MPDA polymer (260 °) appear are evidently due to the fact that for the formation of a volatile product in the model system single bond rupture is sufficient, while in a crosslinked polymer, a minimum of two bonds have to be ruptured. At 250-2605 (Figure) the number of breakdown products suddenly increases (in composition and Concentration) in mass-spectra of both polymers which is evidence of a degradation process t~king place [1]. Degradation of polymer I I gives a spectrum of products (Table 3) which depends on the formation of new weak bonds as a result of kinetic chain transfer to CH3--, - - N H - - and NCH~CH~N groups, which are absent from polymer I.

T. S. F_,zmcm~A ~¢ ~l.

2"198

CI

I I

27O

43 6O !

I I

b

278

I° |

I~

~2G8

I

,J L.~ uJJ.~ L.

lq7

228

256

19

3

LL

L 228

e I9

19

L

I

7t2 qq

28q

i

320 3q03~ 376

9~

t3q

f

228 252 268 2'32

II I B~

I 2~ 3O2

t~

i

II

!

Mm~-spectm of thermal breakdown products of polymor II at 50 (a), 140 (b), 200 (0), 260 (d), 30o (e) and 3Z5 ° (f). Unreactod I~H groups present in both polymers affct degradation differenCly. In polymer ]I during eham transfer to tho N H group an aminyl radical is formed :---:-CH.-~-CH~ICH.',.'--CH(OH~ which either take8 p ~ in further

prooe~es of chain transfer, or breaks down st~pwise from C--C bonds in the p-lx~ition. In polymer I the stable aromatic amlnyl radical is of low activity in chain transfer and inhibits breakdown [2] ~NCeH4NCH~~.'--CH(OH)~,~. Significance is attached to a considerable number of products obtained from

Thermal breakdown meehsnism of'crosslinked polymers TABL~ 3. Tm~,aA,. ma~A~ow~ ~aOD~ym oF ~ O L ~

2T99

I I AT 20-330 ° n~ VAVOv~ (10.4 Pa)

role

Product structure HIO, HsO + CO (28), HN=CH~, C H t f C H t (28) HsC-~O, H~NOHs (31), CHaCH s CHsCH=CH ~ (42), CHa=I~CHs (43), HsNCH=CH~ (43) CH=CH= O, CHsCHICHj H2NCHsCHs, HN(CHs), H~NCH=CHCH3 (57), H N = C H C H O (57), CH~=COCH~* (57), HN=OHCHtNH~ (58), CH~C(O)CH, (58), O = C H C H = O * (58), CH~=CHOCHa* (58) C6HIOH C,H6~)=CH, (107), C6HsOCH, CH2 = NCH,CHgNHCH = CHCH3

18, 19 29 30 42, 43 44 45 56, 57 94 108 112

0

C,H60CH = CHCH 3, CH~-= C(CH3)CeHtOH,

134

--(~=0 H(--HNCHtCHI--)sNHt (146), CHs(~H,NHglH~CH,NHCHtCH(OH)CH, (146), (CH s),NCCH,CrH~NHCH sCH (OH )CH, (I~6), CHsNHCHzCH~N(CH,)CH~CH(OH)CHs (146) O

147

148

I

C CHs 0 C.H~OOH,C(O)CH~ C.H~OCH =CHCH~N-----CH, (161), CH,CH(OH)CH,N-HGH,CH,I~HCH,CH,NHj (161) CH,(-- HNCH,CH,--),NHCH,, CH ,CH,I~(CH,)CH,CH,N(CH,)CH,CH(OH)CH,, (CHs),NCHsCHsN( -- CHsCHs) CH,CH(OH) CH,, CH sC(0) CH ~NHCH2CHs~VHCHsCH(0H) C'H*, 0 ~ / /

~CH~

~

CHs

CH.

174

CHaNHCHzCH~NCHsCH~H

C=O CHs (173) CHs CHaCH(OH) CH~N-HCHsCH~HCH~CH(OH) CHs, CH, = C(CH,)C~I,OCHzCH ffiO (CH,) =NCH,CH ~NHCH ,CH ~ ' H C H ,CH ~TICH s, CHaCH,N(CH,)CH,CH,N(-- CH,CH,)CH,CH(OH)CHs, CH sC(O)CH ,N(CH3)CH,CH,N'HCH,CH (0H)CH,, O H2~ ~

150 162

176 188

2800

T.S. Z&mrn',wA~ a/. T~s.sLs 3 (oo~.) Product structure

role

CH,C (O)CH,OC.H.CH(CH.) g (192). CHICHCH2OC.H.CH(CHs) , (192).

193

Y

H,NCHICH,NHCH = CHCH,OC.H. (192). CHsCH(OH)CH.OC.J~4C(CH,) ----CH. (192). (CHs) .NOH,C(0)CH.OC,H.. CHsCHINHCH,C(O)CHIOCoH, (CH1),NCH,CH(OH) CH,OC.H~ (195). CH,CHtNHCHzCH(OH)CH,OC,H5 (195)

196

CHs = NCH,CH,N{CHs) CH,CH,I~(CHs)CH,CH,N = CH, (CH s).NCH,CH,N(CH .)CH,OH,NHCH,CH,NHCH. (202).

CH,C(O)CH,N(CH.)CH,CH,N(CH.)CH,C(O)CH. (200). CHaC(0)CHzN(-- CH,CHs)CH,CH,NHCH,C(O)CH. (200) H,NCH.CH,NHCH~CH(OH) CH,OC.H6 OH HOC.H.C ( = C H , ) C H , - - ( ~ / -

¢

198 200. 202 210

226

J

HOC,H4C(CH.),C.H.0H (228). CH,= NCH,CHzN-HCH,CH,.N[-- CH,C(O)CHs], (227) (CHs),NCHzCH,NHCH,CH(OH) CH,OC.H~ OCHa

228. 229

HOCoH,C (==C H , ) C H , - - ~ /

240

238

CH8 / CH

O

~

O

H

,

252

/ CHa CH HC (O)CH,NHCH,CH,NHCH,CH (OH) CH,OC~Hs,

CH3CH,NHCH.CH,N(CHs)CH,CH(OH) CH,OC,H.. (CH~),NCH,CH,.N(CH3)CH,CH(OH)CH,OC.Hs. H,NCH,CH,NHCH,CH(OH) CH,OC.H,CH(CH,), CH(O)CH.~CH , C H , N H C H , C H ( 0 H ) CH,OC6H,

H.CCH = CHN(CHs)CH,CH,NGH,CH,NHCH,CHCH,

I

;H

CH=CHCHs CH,OC6H~C(CH,),C,HIOCH, (256) CHsNHCH,CH,NHCH,CH(0H)CH,OC,H,C ( -----CH,)CHs, CH,C(O)CH,NVHCH,CHaNHCH,C(O)CH,OC6H,, CH,CHsN(CHB)CH~CH,N(CH,)CH,C(0)CH,0C~H6, ttsC \ C CH2 - - C ~ CH. H,C/ff ~

253 255 256. 257 264

~.H,0H

OH CH.NHCH,CH~THCH.CH(OH) CH,0C,H.CH(CHJ,. CH,CH(OH) CH,NHCH,CH,17HCHsC(O)CH,OC,H6, GHsCH,N(CH.)CH.CH,(CH.) CHzCH(OH)CH,OCoH,. CH.CH,N'HCHzCH,N(CH.CH.)CH,CH(OH)CH,OC.Hs. HC(O)CH.N(CHa) CHzCH,,NHCHzCH(OH)CH,OC.H,

266

Thermal breakdown mechanism of crosslinked polymers

2801

T~L~ 3 (co.~.) Product structure

CH3CH= CH-N(CHs)CH=CH2N(CH,)(2HsCH(OH)CH~OO6Hs, CHsC(0)CH,N(CHs)CH,CH~THCH,C(O}CH,OCsH,, (CH,),NCH,CHIRrHCH,CH(0H)CH,00,H,C(=CH,)CHa, 0HsCH ,NHCH,CH ,I~VHCH,OH (0H)CH,0C~HsC (= CH~)CH3 (CHs),NCH,CHsNHCH,CH(0H)CH,0CoH,CH(CHB) ,, CH3CH(0H)CH~N(CHa)CH~CHzNHCH~C(O)CH=OC.Hs CH. CH~

'~,

C-~,,

\CH,_O

m]e

; 278

280

282

/

%0

CIt3

",,.C7 " ,%

0 CH3CH(OH)CH,N(CH,) CHsCHsNHCH,CH(OH) GH,0C.H~ CHsC(O)CH,0C,H,C(CH,),Cj-I40H, HC(O)CH,OO,H,C(CH,),C6H,OCH,, HOCeH4C(CH3),CeH,0CH~CHOH,

284

CH.C (0)CH,NCHzCH,NCH,CH,I~ICH

285

"d"

,C(0)CH~

~H,c(oic~,

l CHs

HOC,H,C(CHs)2C,H,0CH,CH(OH)CH,, CH3OC,H,C(CHs),C6H4OCH~CH,0H CHa

286

C' ~

292

CH~, /

.... ~ ~ O C H - - - -

CHCHs,

CHIn

CIt C,H,OCH,C(0)CH,NHCH2CH,,N(CH,CH,)CHsC(0)CH,, C,HsOCH,C(0)CH,N(CH,)CHICH,~{CH,CH,)CH,CH0, C6Hs0CH,CH = CHN(CH,)CHICH,N(CH,CH,)CH,CH(OH)CHs, C,H60CH,C(0)CH,~N(CH.)CH~CH jN(CH,CHa)CH,CHO, CH~CH = CHNHCH2CH,NHCH,CH(0H)CH,OC6H4CH(CHs) CH3 294

l CH /

CH.

CH CH(O)CH,NHCH,CH~'HCH,CH(0H) CH,OC.H~CH(GHs)z, C~H~OCH,CH(OH)CH~(CH~)CH,CHsl~T(CH,CHf)CH,CHO, C.H,OCH.C(O)CH .N(CH.)CH ,CH~(CH~)CH.CH(OH)CH~, CH~CH~rHCH,CH~N(CH~)CHsCH(OH)CH,OC~H~CH(CH~)

1~902

T.S. Z ~ A

a a/.

T,tm,z 3 (con&) Product structure CHoCH (0H}CHtN(CH J CH ,CH tN(CHI)CH,CH (OH~,O(~Ho C H ,CH(OH)CH~NHCH ,CH tNCHsCH,N ( C H . C H , ) a H , C ( O ) C H , .

302, 303

CH,C(OI~H, CH s-"NCHsCHO

/

\

Ceilo0CH,C(0)CH~'(CH .)CH

\

/

302,303

CH

CH..- CH CH. 0 --

~

-

OCH,CHO,

308

CIt-- CrH. CH,C(OICHIN(CH~ICH,CH.N(CH,CH,)CH,CH(OH)CH,OC.H.. CH.CH (OH)CH~'~ICH sCH,~ HCH,CH(OH) CHnOC~H,C(-- CH,JCH.. C.HIOCHIC(O)CH~(CHICH s)CH.CH .N(CHJCHICH (0H)CH.. CH,CH ~N (CH,)CHtCHtN(Cq4,)CH,CH(OH)CH,OC,H,CH(CH,)t. RC(O)CH~HCHICHINICH,)CH riCH(OH)CH nOC,H6CH (CH s), C,HsOCH,C(0)CH~HCH,CH,N[- CH,C(O)CH,],. C,HIOC~,CIO)CH~N(CH,)CHICHsN(CH "-CHCH,)CH,CH(0H)CH, CH,CH (OH)CH ~ I C H o)CHICH IN~CH ,)CH --=C~ICHaO(AH,CH (CH,), CH ~CH(0H)CH~'(CH.CH,)CH sCH.N~IC~ = CHCH,OCoH,CH(CH.). CH. / HO

320

CH.H(- C.}I,OH).

",U

322 324 327

CH.CH(OHICH,NICH.)CH.CH~HCH.CHIOHICH.OC.H,C(--CHdCH. C H . C H ( O ~ . N ( C H JCH.CH ,NHCH.CH (OH)CH,OC.H,CH(CH.). CH.= NCHsCHIOH)CH,OC.H,C(CHº)sC.H,OCH. (CHJ,NCH.C(O)CHnOC.H,C(CH.).C.H,OH CH.CHIOH)CH.OC.H,C(CH.).C.H,OCH,CHO CH,C(O)CH,OC.H,C(CH.).C.H,OCH.C(O)CH. (340). C~.NHCH,CH~NHCHsCH = CHOC.H,C(CHJsC.H,OH (3401, CH3 CH.CH(OH)CH,O- ~" ,-~ ,-L /~

[

- ~X = _ , / ~

~H.

328 340, 34 !, 342

- -0

~ \

CH.

(340).

CHn--/ CH.=NCHtCH =CHOC,H,C(CH,),C,H,OCII,CH,OH 13397 CH,

C~,.-..~C~,C(OICH,O-( f ~

~/ ~-~----(, (~H,

~

/CH. C

%

(3511,

Ji !

L

352

Thermal breakdown mecba_ni~mof crosslinkod polymers T~

2803

3 (cont.)

role

Product structure CH, ----NCH~C(O)CH,OC~I~,C(CH,),C6H4OCH-~CHCH3 (351), CH, ~ I~TCH.CHzl~(CHa)CH~-CHCH,OC6H,C(CHs)zCeH~OH (CH,CH.)~'NTCH,CH(OH)CH,OCeH,C(CHa)ICeH,OH (357), CH~THCH2CH2NHOHICH(OH)CH~OCeH4C(CH3)2C~H4OH, CHs H0-- ~

C

358

358

0ffH C t CIt2 CIt~

O,

/~_~-~l--~--

OCH,C(O)CHiN~ CH~

365

C--CH 2 / O CHsCH~N(CH3)CHaCHsNHCHIC(O)GH~OC,H,C(CH3)2C6H4OH (CH3)zNCHzCHzN(CH,)CH2C(O)CH2OCsH,C(CHs)sC,H4OH

384

the rupture of Cal--Carbonds (m/e-~-193, 208, 226, 240, 252, 264, 266, 277 (Table 2) ) formed at 70-100 ° in air. This is, apparently, due to the presence of six CHa hydrogens in a 2,2'-propylidene diphenol group, which react with RO0" radicals formed under these conditions. In a CsHI+C(CH2) (CH3)~-CeHt " radical both Cal--Car bonds are weaker by 60-80 kJ/mole and are readily ruptured, giving an~OCeH4C(CHs)----CH~ fragment with a double bond and an active phenyl radical "CeHiO~.Products with m/e~134, 148, 174, 188, 252, 282, 292, 294, 308, 340, 352, 365 (Table 3) and with m/e-~134, 148, 150, 152, 160, 162, 164, 166, 174, 176, 188, 190, 192, 196 and 200 (Table 4) containing cyclic fragments X HC/ ~.~'~ - x - '

X H.C/ " ~ ' / "

X- ,

1 HO

X

=e\Uk/-

II 0

X

HCI ~y~,~ X -,

X H.C/ " ( ) - - X , ~ .

H2C/ ~ \

A j -x-,

X i t : O / "-,<(',%

At]

~where X-----.O., --NR--, are formed by the reactions

2804

T . S . ZAu[mNa. a a/. X +R" ~X_~ III

/ "~HsTR H '%,,'--CH l

II

OH --tH

o. --H~

i

1

X

X

~X.-()/ X -.,X--~

\CIt:~H

-*

\CHt C=O

_x_,/) /

'%.,'--CH

x

~ - ~ . ~ .| ~

+n ' ~a--:.

_..,X_ll

,v

--~H

11 II

t,

-I- RH

0H

--H.O

!

~X_~/"

!

X \CII2

X

~ x _ ( f " y / \CH

0

Macroradicals III formed as a result of the rupture of Cp-CaN and Cp- C=O bonds of a 2-hydroxypropane bridge decay as a result of reactions of intramolecular radical substitution of the hydrogen atom in the aromatic ring in tile ortho-position to the hetero-atom and subsequent disproportionation. Fivemembered benzoannelated cyclic fra gments (derivatives of benzofllranes, indoles, etc.) are formed. With rupture of Cil--O-tcr or Cat--N bonds decay of macroradicals IV by this mechanism results in the formation of six-membered cyclic structures (derivatives of chromanes, chromenes, hydroquinolines, etc.). Products containing cyclic fragments of similar structure were detected chromatographically by Pat terson-Jons et a/. [8] during vacuum thermolysis (10-:-10 -5 Pa) at 304 ° for 2.5 hrof a crosslinked polymer -the reaction product of DGED with p,p'-diaminodiphenylmethane taken in a stoichiometric ratio. Ring formation is a method of kinetic chain t(.rmination as a result of disproportionation of a stable radical. We have shown previously [3J that the reaction of radical substitution of the hydrogen atom in an aromatic ring may also take place by an intermolecular mechanism. Products of this reaction are given in Tables 2 and 3 (m/e=186, 226, 240, 264, 266). Disproportionation of aliphatic radicals resulting basi(~dly in keto-containing fragments is the predominant reaction of kinetic chain termination. Main products of most stepwise reactions of breakdown of polymer I am resorcinol, 6-hydroxybenzofurane, water, acetaldehyde, CH:----NC,H~NHCH3 (Table 4) and C,H6OH, HOC6H,C(CHs)zC,H,OH, HOC,H,C(=CHz)CH:, H.O, HzC=O, N H = C H s , CH~N---CHz, CHsCHO, CHzC(O)CH: (Table 3)are formed

Thermal b r e a k d o ~

mechanism of crosslinked polymers

2805

TABLE 4. PI~ODUCTS OF T~USRMALDE~4RADATION Oit' POLYMER I AT 20-400"0 iN v ~ c v u M (10-1Pa)

role

P r o d u c t structure

H,0, H,0+

18, 19

CHsCH0

43-45

HOCeH,OH

110 124

HOCeH40CH8 0

CH2 = N

\

E 134

CH

~H, 136

CH,HNC6H,NHCHs

138

CHsOCeH~0CH,

0

0 /" HC

0CH8

OH \\

(CH.)~NCeH4N= CH2

148

\/

I-IC~ 0

ttOC,tt,OCH = GIICHs, (OH.) ,~C,H,~-~CH, 0

HO

150

OCHzCII

'o'

\

CH, --~H-- O H HOCeH,0CH,CH20H CH8 I N

152 154

160

H,C0

0

\

/

/

\ell

162

\/

Cl:Is 0

0

164

C=O'

UI:IaOC~tt,OCtt = CR'Ctts,

(C~I)

~0,tt,N

(~,)

a

2806

T. 8. Z ~ m ~ m m A

e .~.

T~L~ 4 ( ~ ) m/,

Product structure

0 CH,O

"~.

/'

0 \

HO

CH,

/

\CH,

---~H-O~ ~ , _

166

&-o~

CH,OC,H,OCH,CHO, HOC,H4OCH,C (O)CH, HOC,H,OCH,CH (OH)CH,, CH,0C,H,OCH,CH,OH

168 CH,

. /o\

oc~=c~..

/ CH2=N ~]~/

~

(c..).N

CH,

"" ~ CH,N CH, , 1 ---~=0 "~'~

-~--U

NCH =CHCH,

\CH, /

O ./~o~..~

CH,

~,~/~.. N

.-.~

~

176

. . . . ~_o

CH,

CH,=N

174

CH,

N/

H.C

/

('H,HNC,H,N (CH,)CH,CH0 H,COC,It4OCH,CH (OH)CH, H,C CH, O HC

178 182

188

CHj HC

HC--GH,

CHaCH'=CHOC,II,OCH=CHCH,. CHs= NC,H,NCHICCH=.

~..~

g H,CH=CHO

0

",~/ \oH. -~-o

CH,CCH,0~"

0

~) " ~ ~ ~

~CH

190

Thermal breakdown mechanism of crosslinked polymers

2807

T~a~m 4 (oon¢.)

role

Produc~ structure HOCH~O II

O

/

O

,~//

CH~

/ \ell \N / \ II / \1./~/ CH~ ~C~ oH' CH, "~f ~=0 CHa

CH,=~

/

CHa

/

CH8

CH3

N

"CI-I, . CH, CH--0H

/ \(\/

\

~

CH=CHCH,

CI-I~ 0 " ~CI:I

CH~CHCH,O

0 CH,CH=CHO

~CH,

/

192

CHsCH-- CHOC.H,OCH2CHO, (OH,)~NC.H~N(CHs)C ~ O ,

0

6'ti,

/

°"

o.. ,-OH

CH~= NCtH4N(CH,)CH~CH(0H)CH3, CHsNHC~H,NCHaCCH~ CH3

H

H~C/ ~ /

\CH,I CH--OH

\7

CH~

CHsHNC,H4N(CB~4[~'~l[l~OH[43I~, (CHJ tNC.H~I (CH~)CH~CH2OH CHsCH-----CHOCsH4OCHICH~OH, HC(O)CH~OCsH4OCH~CHO O HCCHsOC6H4OCHICHs, H~3CH20. //

194

196

I(~-I--OIt

HOCH,CHzOCsH,OCH~CH~0H CH~C(0)CH3

°"%A/"-o=

198 200

K. 8. Mnmxms J d.

2808

during the breakdown of polymer If. These compounds sa'e similar to breakdown products of model systems, therefore, the ~ u e n c e of breakdown r~ctions proposed by us for models [2, 3] is also applicable to polymers in spite of the "non-ideal nature" of their structure. Transhged by E. S~E]gE REFERENCES

1. L. 8. Z A ] g ~ I N , A. N. ZELENETKKII, L. V. KARMILOVA, E. V. PRUT and N. 8. YEN'IKOLOPYAN, Dok]. AN SSSR 2 8 9 : 2, 360, 1978 2. L. A. ZHORINA, L. 8. ZARKHIN, A. N. ZELENETSKH, Ye, I. KARAKOZOVA, L. V. KARMILOVA, Ye. N. KUMPANENKO, V. P. MEL'NIKOV, Ye. M. NECHVOLODOVA and E. V. PRUT, Vysokomol. soyed. 28: 2817, 1981 (Not translated in Polymer Sci. U.S.S.I~.) 3. T. 8. Z ~ R R H I N A , A. N. ZELF~h'ETSKII, L. S. ZARKHIN, L. V. KARMILOVA, E. V. PRUT and N. 8. YENIKOLOPYAN, Vysokomol. soyed. A24: 584, 1989 ~'Frazlsbl~d in Po. lymer Sci. U.S.S.R. 24: 3, 647, 1982) 4. L. K. PAKHOMOVA, O. B. 8ALAMATINA, 8. A. ARTI~-MF.NKO and AI. AI. BERLIN, Vysokomol. soyod. BZ0: 554, 1978 (Not tra~slated in Polymer Sci. U.S.S.R.) 5. AI. AI. BEllIJlq and V. G. O8HMYAN, Vysokornol. 8oyccl. A18: 2282, 1976 (Tranalate(i in ]~olymer Sci. U.S.S.R. 18: 10, 2012, 1976) 6. V. A. TOPOLKARAYEV, V. G. OSHMYAN, V. P. NISICHENKO, A. N. ZELENETSKIJ, E. V. PRUT, A/. AI. BERLIN and N. S. YF_~'IKOLOPYAN, Vysokomol. soycd. A21: 1515, 1979 (Translated in Polymer Sei. U.S.S.R. 21: 7, 1663, 1979) 7. 8. Z. ROGOVINA, M. A. 8TAK'HOVSKAYA, M. A. MAItKI~.VICH, A. N. ZELRN'ETSKII, D. D. NOVIKOV and N. 8. YENIKOLOPYAN, Dokl. A~N SSSR ~ : 1, 140, 1977 8. E. 8..LEISEGANG, A. M. STEPHEN and J. 8. PATrEKSON-JON8, J. Appl. Polymer Sci. 14: 8, 1961, 1970

8~deooe U.,q.S.B, VoW.24.

No. II, pp. 28(~..-~1~ 1082

Prl~ed In Poland

00S~-S960/82 $7.50+ .00 O 1 ~ 8 Perl~moa P ~ m Ltd.

E F F E C T OF CONJUGATED D I E N E S ON CROSSLINKINO OF P O L k A ) R I D E * K. S. MmSK~, S. V. Kot, r.sov and V. V. PrrRov Bashkir State University namod a f t e r the 40th Anniw,rsary of October

(Received 7 July 1981) I t wsa ahowli that c~)njugat~i dient~ i n h i b i t macro.chain crosslinking in thernml degradation of PVC. A reduction in tile rato of crosalulk formation and aal i n c r e ~ e in the induction period of gel.fornmtion is due to a reduction in tile oonte1~t of ~L,u m * Vyaokomo]. soyed. A~4: ~'o. 11, 2443-2446, 1902.