Modification of Polymers - American Chemical Society

6 Incorporation of Metal Ions into Polyimides

Downloaded by NANYANG TECHNOLOGICAL UNIV on October 17, 2017 | http://pubs.acs.org Publication Date: June 10, 1980 | doi: 10.1021/bk-1980-0121.ch006

1

L. T. TAYLOR, V. C. CARVER, and T. A. FURTSCH Department of Chemistry, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 A. K. ST. CLAIR NASA Langley Research Center, Hampton, VA 23665

The effect of ionic groups on the properties of bulk polymer has normally referred to studies on polyelectrolytes in which an ionic group is covalently attached to the polymer chain which is usually neutralized by a metallic counterion. Studies of systems consisting of neutral polymers with dissolved inorganic salts are only beginning to receive considerable attention. The results of the incorporation of ions in polymers and their effect on the glass transition temperature (Tg) has been reviewed through 1969. Therefore, only the more recent and pertinent reports will be mentioned here. Large increases have been produced in the Tg of poly(propylene oxide) by dissolving LiClO in the polymer. Crystallization adducts of poly(ethylene oxide) that have been treated with HgCl or CdCl have also been reported. Solutions of Ca(NCS) and "Phenoxy" polymer have significantly different physical properties compared to the pure polymer. Increased water absorption, Tg and electrical conductivity are results of salt incorporation. Mechanical properties of these glassy polymers are also affected by the presence of dissolved salt. Investigations regarding the interaction of inorganic nitrate salts with cellulose acetate, poly(vinyl acetate), poly(vinyl alcohol), poly(methyl methacrylate) and poly (methyl acrylate) have been cited. In addition to observing large effects in Tg , large shifts in the infrared spectrum of both nitrate and polymer carbonyl frequencies have been observed. These observations have been interpreted in terms of complex formation between polymer and salt in the solid state. The change in Tg was shown to be an unusual function of metal ion concentration (i.e. Tg increases with increasing metal concentration up to (1)

2 ()

(3)

4

2

(4)

2

2

(5)

(6)

1

Current address: Department of Chemistry, Tennessee Tech-

nological University, Cookeville, TN. 38501 0-8412-0540-X/80/47-121-071$05.00/0 © 1980 American Chemical Society Carraher and Tsuda; Modification of Polymers ACS Symposium Series; American Chemical Society: Washington, DC, 1980.


72

MODIFICATION OF POLYMERS

a maximum p o i n t t h e n Tg b e g i n s t o d e c l i n e ) . The e f f e c t s o f v a r i o u s m e t a l s a l t s on t h e T and c r y s t a l l i n i t y o f some p o l y a m i d e s h a v e b e e n n o t e d M i x t u r e s of Nylon 6 and e i t h e r L i C l , L i B r o r KC1 were p r e p a r e d by m e l t i n g i n v a c u o a t 260°C an i n t i m a t e b l e n d o f t h e two c o m p o n e n t s . The e q u i l i b r i u m m e l t i n g t e m p e r a t u r e o f p u r e N y l o n 6 was c o n t i n u o u s l y d e p r e s s e d by i n c r e a s i n g s a l t c o n t e n t w i t h KC1 b e i n g t h e most effective. I n t h e s e s t u d i e s t h e s a l t c o u l d be e x t r a c t e d f r o m t h e polymer w i t h hot water w i t h complete recovery of the f u s i o n t e m p e r a t u r e w h i c h i s c h a r a c t e r i s t i c o f p u r e N y l o n 6. The o c c u r r e n c e o f a s t r o n g i n t e r a c t i o n p o s s i b l y b e t w e e n t h e amide g r o u p o f t h e amorphous p o l y m e r and s a l t s s u c h as L i C l and L i B r was predicted. In a l a t e r stud 3^)these workers i n v e s t i g a t e d the e f f e c t o f t h e s e s a l t s on t h e g l a s s t r a n s i t i o n , T . Tg i s n o t a f f e c t e d by t y p e and c o n t e n t o f m e t a l s a l t . Mecnanical data f o r u n o r i e n t e d specimen of Nylon 6 - s a l t mixtures r e v e a l t h a t below Tg t h e s h e a r m o d u l u s i s n o t a f f e c t e d by t h e s a l t . Whereas above Tg t h e m o d u l u s o f N y l o n 6 i s i n c r e a s e d by KC1 and d e c r e a s e d by L i C l and L i B r . The N e w t o n i a n m e l t v i s c o s i t y was c o n s i s t e n t l y h i g h e r f o r the mixtures than f o r pure Nylon 6 i n each case. It s h o u l d be n o t e d , h o w e v e r , t h a t L i B r and KC1 w e r e more e f f e c t i v e than L i C l i n causing the v i s c o s i t y i n c r e a s e . The employment o f t r a n s i t i o n m e t a l s a l t s w i t h n e u t r a l p o l a r polymers i s n o t i c e a b l y l a c k i n g . R e c e n t l y , the a d d i t i o n of ZnCl2 and C0CI2 t o h i g h and t o l o w m o l e c u l a r w e i g h t p o l y ( p r o p y l e n e o x i d e ) has b e e n r e p o r t e d £1) ZnCl2 was f o u n d t o i n c r e a s e t h e Tg o f b o t h h i g h and l o w m o l e c u l a r w e i g h t p o l y m e r b u t C0CI2 o n l y i n c r e a s e d t h e Tg o f t h e l o w m o l e c u l a r w e i g h t p o l y m e r . A s i n g l e p h a s e s y s t e m i n t h e ZnCl2 c a s e was i n d i c a t e d ; w h i l e a two p h a s e s y s t e m w i t h C0CI2 a c t i n g as a f i l l e r was s u g g e s t e d . In t h e z i n c c a s e , t h e e l e v a t i o n o f Tg i s b e l i e v e d t o r e s u l t f r o m t h e f o r m a t i o n o f f i v e - m e m b e r e d c h e l a t e r i n g s by c o o r d i n a t i o n o f two a d j a c e n t o x y g e n atoms i n t h e p o l y m e r c h a i n w i t h a ZnC^ molecule. I n an a n a l o g o u s s i t u a t i o n , ZnCl2 was added t o p o l y ( t e t r a m e t h y l e n e g l y c o l ) w i t h s i m i l a r r e s u l t s a l b e i t t h e Tg was r a i s e d l e s s f o r a g i v e n amount o f m e t a l c h l o r i d e . Intermolecular c o o r d i n a t i o n w i t h e t h e r o x y g e n atoms f r o m two n e i g h b o r i n g c h a i n s was p o s t u l a t e d s i n c e i n t r a m o l e c u l a r b o n d i n g t o z i n c ( I I ) w o u l d i n v o l v e t h e f o r m a t i o n o f a l e s s s t a b l e seven-membered c h e l a t e ring. A n g e l d — / h a s b r i e f l y r e p o r t e d i n a patent the a d d i t i o n of metal ions to s e v e r a l types of p o l y i m i d e s . The o b j e c t o f t h e i n v e n t i o n was a p r o c e s s f o r f o r m i n g p a r t i c l e - c o n t a i n i n g ( < l u ) t r a n s p a r e n t p o l y i m i d e shaped s t r u c t u r e s . U n l i k e the work d i s c u s s e d p r e v i o u s l y , a l l o f t h e m e t a l s w e r e added i n t h e f o r m o f c o o r d i n a t i o n c o m p l e x e s r a t h e r t h a n as s i m p l e a n h y d r o u s o r h y drated s a l t s . The p r o p e r t i e s o f o n l y one f i l m ( e . g . c a s t f r o m a N,N-dimethylformamide(DMF) s o l u t i o n of 4 , 4 - d i a m i n o d i p h e n y l m e t h a n e , p y r o m e l l i t i c d i a n h y d r i d e and b i s ( a c e t y l a c e t o n a t o ) f

Carraher and Tsuda; Modification of Polymers ACS Symposium Series; American Chemical Society: Washington, DC, 1980.

6.

TAYLOR ET AL.

Metal Ions in

73

Polyimides


c o p p e r ( I I ) ) were g i v e n . These p r o p e r t i e s i n c l u d e d : %Cu = 3.0%, d i e l e c t r i c c o n s t a n t = 3.6 a n d v o l u m e r e s i s t i v i t y = 8 x 1012 ohms-cm. No f u r t h e r p a t e n t s o r p u b l i s h e d w o r k i n t h i s a r e a a r e apparently availableQj). S i n c e a r o m a t i c p o l y i m i d e s have proven t o be e x c e l l e n t h i g h t e m p e r a t u r e a d h e s i v e s a n d l i m i t e d d a t a suggest that a d d i t i o n o f metal o r m e t a l l o i d m a t e r i a l as a f i l l e r may enhance£L2) a d h e s i v e p r o p e r t i e s , we w i s h t o r e p o r t o u r results r e l a t i n g to the incorporation of a series of metal ions into various polyimides. R e s u l t s and D i s c u s s i o n f

P o l y i m i d e s d e r i v e d from 3,3 ,4,4'-benzophenone t e t r a c a r b o x y l i c a c i d d i a n h y d r i d e (BTDA), I , and 3 , 3 - d i a m i n o b e n z o p h e n o n e (m,m DABP), I I A , 4 , 4 ' - d i a m i n o b e n z o p h e n o n e ( p , p - D A B P ) , I I B , o r 4 , 4 o x y d i a n i l i n e , I I C , ( a n d t o w h i c h h a v e b e e n added numerous m e t a l compounds) h a v e b e e n p r e p a r e d . The s y n t h e t i c p r o c e d u r e em1

!

f

ii 0

BTDA I

f

T

ii 0

m,m -DABP, X = C=0, I I A p,p -DABP, X = C=0, I I B p,p -0DA, X = 0, I I C !

f

p l o y e d i n v o l v e d (1) f o r m a t i o n o f t h e p o l y a m i c a c i d (20% s o l i d s ) i n e i t h e r DMF, N , N - d i m e t h y l a c e t a m i d e ( D M A C ) o r d i e t h y l e n e g l y c o l d i m e t h y l e t h e r (Diglyme) (2) a d d i t i o n o f t h e m e t a l c o m p l e x t o t h e p o l y a m i c a c i d , I I I , i n a 1:4 r a t i o (3) f a b r i c a t i o n o f a f i l m o f t h e p o l y a m i c a c i d - m e t a l compound m i x t u r e and (4) t h e r m a l c o n v e r s i o n (300°C) t o t h e m e t a l c o n t a i n i n g p o l y imide. A p p r o x i m a t e l y twenty m e t a l s i n a v a r i e t y o f forms were added t o t h e p o l y a m i c a c i d s o l u t i o n s . Several experimental problems were e n c o u n t e r e d i n f o l l o w i n g t h i s p r o c e d u r e

r

o II

o II

o II

III


n

74


w h i c h l i m i t e d t h e number o f good q u a l i t y f i l m s o b t a i n e d . T h e s e problems i n c l u d e : (1) m e t a l complex n o t d i s s o l v i n g i n appropriate solvent, (2) g e l f o r m a t i o n o r c r o s s - l i n k i n g o f t h e p o l y m e r o c c u r r i n g upon i n t e r a c t i o n w i t h t h e m e t a l , (3) polyamic a c i d p r e c i p i t a t i n g when t h e m e t a l c o m p l e x i s added and ( 4 ) m e t a l promoting thermal o x i d a t i v e d e g r a d a t i o n o f t h e polymer f i l m upon c u r i n g . I n g e n e r a l p o l y i m i d e s d e r i v e d f r o m BTDA + p,p -DABP y i e l d e d r a t h e r p o o r q u a l i t y , v e r y b r i t t l e f i l m s w h i c h w e r e due i n p a r t to t h e l o w v i s c o s i t y o f t h e r e s u l t i n g polyamic a c i d s o l u t i o n . This fact, coupled w i t h theobservation that theadhesive prope r t i e s o f t h e p,p -DABP i s o m e r a r e p o o r e r t h a n t h e a d h e s i v e p r o p e r t i e s o f t h e m,m -DABP isomerCL^J d i c t a t e d t h a t a n y e x t e n s i v e p h y s i c a l measurements s h o u l d be c a r r i e d o u t on t h e l a t t e r . T a b l e 1 l i s t s some o f t h e m e t a l compounds e m p l o y e d a n d t h e r e s u l t s o b t a i n e d when a t t e m p t s w e r e made t o c a s t f i l m s o f t h e r e s u l t i n g m e t a l i o n f i l l e d p o l y i m i d e d e r i v e d f r o m BTDA + m,m DABP. B r i t t l e f i l m s w e r e p r o d u c e d i n most c a s e s r e g a r d l e s s o f w h e t h e r t h e added m e t a l i o n was h y d r a t e d o r a n h y d r o u s . The r e l a tively low v i s c o s i t i e s o f ther e s u l t i n g polyamic acid-metal i o n s o l u t i o n s no d o u b t a c c o u n t e d f o r t h i s . Addition of AlCl3 6H20 o r a n y s i m p l e a l u m i n i u m s a l t t o t h e p o l y a m i c a c i d p r o d u c e d immed i a t e l y a r u b b e r y m a t e r i a l t h a t c o u l d n o t be c a s t i n t o a f i l m . A s i m i l a r r e s u l t was o b t a i n e d w i t h T i C O E t ) ^ a n d Ni(acac)2»


f

f

f

f

#

Table 1 F i l m s Cast BTDA+m,m -DABP P o l y m e r a n d M e t a l I o n s * f

Metal Compound

Results

Results

Mn(acac)^

very b r i t t l e rubbery

material

Al(acac)^

flexible

A1C1

rubbery m a t e r i a l

Ti(OEt)

s u r f a c e DMAC

SnCl » 2 H 0

brittle

film

CrCl « 6 H 0

brittle

film

MgCl * 6H 0

brittle

film

Fe(acac)^

brittle

film

NiCl .6H 0

flexible

Cr(acac)^

brittle

film

CuCl * 4H 0

brittle

Ni(acac)

rubbery m a t e r i a l

AgN0

very b r i t t l e

brittle

CoCacac)^

• 6H 0 2

LiCl 3

CaCl

2

2

2

film

Metal Compound

film

4

2

2

2

2

2

2

2

2

3

brittle

film

film film film

film

* S o l v e n t = DMAC


6.

TAYLOR ET AL.

Metal Ions in

Polyimides

75

L i t h i u m c o n t a i n i n g f i l m s were u n u s u a l i n t h a t t h e f i l m a f t e r c u r i n g was damp o n t h e s u r f a c e w i t h what a p p e a r e d t o be t h e s o l v e n t , DMAC. No o t h e r f i l m s e x h i b i t e d t h i s p r o p e r t y . The AgNO^ c o n t a i n i n g f i l m had t h e appearance o f a s i l v e r m i r r o r b u t t h e f i l m was e x c e e d i n g l y b r i t t l e a n d " f l a k y - l i k e . O n l y two t r u l y f l e x i b l e f i l m s w e r e p r o d u c e d f r o m BTDA + m,m'-DABP. These c o n t a i n e d A l ( a c a c > 3 and NiCl2»6H2O r e s p e c t i v e l y . A r e p r e s e n t a t i v e s a m p l e o f many o f t h e p o l y i m i d e f i l m s t h a t were produced were s u b j e c t e d t o t h e r m o - m e c h a n i c a l a n a l y s i s (TMA), t o r s i o n a l b r a i d a n a l y s i s ( T B A ) , t h e r m a l g r a v i m e t r i c a n a l y s i s ( T G A ) , i n f r a r e d s p e c t r a l a n a l y s i s and w e i g h t l o s s o n p r o l o n g e d h e a t i n g ( e . g . i s o t h e r m a l s t u d i e s ) , TABLE I I . The s o f t e n i n g t e m p e r a t u r e a s measured b y TMA a n d TBA a r e i n g e n e r a l


1 1

TABLE I I TMA, TBA a n d TGA o f M e t a l I o n F i l l e d o f BTDA + m,m -DABP

Polymers

3

f

METAL ION

TMA(°C)

TBA(°C)

TGA(°C)

Fe(acac)^

292

293

412

Cr(acac)^

287

279

#

NiCl

6H 0

279

495

MnCl * 4H 0

279

495

Al(acac)^

271

270

555

CaCl

2

264

266

518

Co(acac)^

268

296

480

C r C l ^ 6H 0

260

LiCl

252

264

480

252

267

520

251

252

570

2

2

2

2

2

MgCl

2

No M e t a l SnCl - 2H 0 2

a

2

460

550

237

S o l v e n t = DMAC; 0.1 g o f m e t a l polymer (20% s o l i d s )

complex ( s a l t ) p e r 4 g o f

Polymer D e c o m p o s i t i o n Temperature


76


i n c r e a s e d when m e t a l i o n s a r e added w i t h t h e e x c e p t i o n o f S n C l ^ * 2H2O. On t h e o t h e r hand, some t h e r m a l s t a b i l i t y h a s b e e n s a c r i f i c e d a s e v i d e n c e d b y t h e TGA d a t a . S o f t e n i n g t e m p e r a t u r e s were more d r a m a t i c a l l y i n c r e a s e d w i t h p,p'-DABP p o l y i m i d e t h a n w i t h t h e m,m -DABP b u t a t t h e e x p e n s e o f c o n s i d e r a b l e t h e r m a l s t a b i l i t y loss. No t r e n d i s a p p a r e n t i n t h e c h a n g e s b r o u g h t a b o u t b y e a c h m e t a l i o n . I n f a c t , each m e t a l i s almost a case unto i t s e l f . T h i s o b s e r v a t i o n i s f u r t h e r d r a m a t i z e d b y some r a t h e r l i m i t e d i s o t h e r m a l m e a s u r e m e n t s o n s e l e c t e d f i l m s (TABLE I I I ) . This d a t a i s t y p i c a l o f t h e m e t a l i o n f i l l e d BTDA + p,p -DABP p o l y i m i d e s w h i c h we h a v e e x a m i n e d . No c h a n g e s i n c h e m i c a l f u n c t i o n a l i t y i n the p o l y i m i d e - m e t a l f i l m were apparent as judged by i n f r a r e d s p e c t r a l comparisons o f p o l y i m i d e a l o n e and p o l y i m i d e plus metal r e g a r d l e s s o f the m e t a l employed. f


T

Table I I I Isothermal Studies MATERIAL

%Weight

f

m,m -DABP m,m -DABP Polymer + Polymer + Polymer + Polymer + Polymer + T

65 h o u r s

C b

Al(acac)3 ' CaCl > LiClc,d Cr(acac)3 > Co(acac)3 >d b

d

2

C

d

c

Loss

3 4 5 7 13 52 13

@ 316°C

^ S o l v e n t = DMAC "Solvent *0.1

=Diglyme

g o f m e t a l complex ( s a l t ) p e r 4 g o f polymer

(20%

solids)

The b e s t s y s t e m s t u d i e d i n r e g a r d t o enhancement o f p o l y m e r properties while maintaining excellent film quality involves t r i ( a c e t y l a c e t o n a t o ) a l u m i n u m ( I I I ) a d d i t i o n t o t h e m^'-DABP polyimide. An i n s p e c t i o n o f T a b l e s I - I I I r e v e a l s t h a t w i t h A l (acac)^ t h e s o f t e n i n g temperature i s i n c r e a s e d without the l o s s o f a n y p o l y m e r t h e r m a l s t a b i l i t y , F i g u r e 1. The r e m a i n i n g f l e x i b l e f i l m , NiCl2*6H20, has a s l i g h t l y lower d e c o m p o s i t i o n temperat u r e than the "polymer-alone" f i l m although t h e s o f t e n i n g p o i n t has a g a i n been i n c r e a s e d . S i n c e t h e m,m -DABP p o l y i m i d e i s known t o b e a n o u t s t a n d i n g adhesive, l a p shear s t r e n g t h t e s t s employing t i t a n i u m - t i t a n i u m adherends and m e t a l i o n f i l l e d p o l y i m i d e s were c o n d u c t e d . Tests w e r e p e r f o r m e d a t room t e m p e r a t u r e , 250°C and 275°C e m p l o y i n g e i t h e r DMAC o r DMAC/Diglyme a s t h e s o l v e n t . A t room t e m p e r a t u r e r e g a r d l e s s o f the m e t a l i o n employed a d h e s i v e s t r e n g t h i s d e T


Metal Ions in

Polyimides


TAYLOR ET AL.



78

creased r e l a t i v e t o the "polymer-alone" case. Again the choice of m e t a l i o n i s c r i t i c a l . The two b e s t c a s e s , i . e . , A l ( a c a c ) ^ and N i C l ^ H ^ O w e r e s u b j e c t e d t o a d h e s i v e t e s t i n g a t e l e v a t e d temperatures. Under t h e s e c o n d i t i o n s the m e t a l i o n f i l l e d p o l y i m i d e s were s u p e r i o r . The A l ( a c a c ) ^ c a s e p r o v e d t o b e e x c e p t i o n a l i n that i t e x h i b i t e d approximately f o u r times t h e l a p shear s t r e n g t h o f " p o l y m e r - a l o n e " a t 275°C. We f e e l t h a t t h i s e n h a n c e d a d h e s i v e n e s s i s due i n p a r t t o t h e i n c r e a s e d s o f t e n i n g t e m p e r a t u r e o f t h e Al(acac)« f i l l e d p o l y i m i d e . T h e s e r e s u l t s a r e somewhat a n a l o g o u s t o d a t a c o l l e c t e d b y S t . C l a i r and P r o g a r e a r l i e i E L ^ ) r e g a r d i n g t h e u s e o f aluminum m e t a l as a f i l l e r w i t h v a r i o u s p o l y imides. L a p s h e a r s t r e n g t h was f o u n d t o d o u b l e a t 250°C w i t h 7 9 % Al f i l l e d polyimide versus theu n f i l l e d polyimide. #


2

Table IV Lap S h e a r T e s t s T i t a n i u m - T i t a n i u m Adherend BTDA-m,m'-DABP M e t a l I o n Added

25°C No

Metal

Al(acac)^

C

N i C l ^ 6H 0

C

2

LiCl

C

Cr(acac)^

3

L a p Shear

0

Strength* ( p s i )

250°C

275°C

2966 (3138)

1573

438 (496)

2378 (2400)

1891

1641 (1348)

1800

1332

608

781

—

—

830

—

—

Numbers i n p a r e n t h e s i s c o r r e s p o n d t o DMAC/Diglyme s o l v e n t m i x ture. ^Average o f f o u r 0.1

tests.

g o f m e t a l c o m p l e x ( s a l t ) p e r 4g o f p o l y m e r

(20%

solids)

S u r f a c e a n d v o l u m e r e s i s t i v i t y measurements h a v e b e e n p e r formed o n f i l m s o f p o l y m e r a l o n e a n d p o l y m e r w i t h A l ( a c a c ) ^ a d d e d . S p e c i a l c a r e was t a k e n t o i n s u r e t h a t o n l y f i l m s o f u n i f o r m l y h i g h q u a l i t y were measured. Regardless of the f i l m pret r e a t m e n t , v o l u m e r e s i s t i v i t i e s o n two i n d e p e n d e n t l y c a s t f i l m s of p o l y m e r a l o n e f a l l i n t h e l O ^ ohm-cm r a n g e . No p r e v i o u s l y p u b l i s h e d r e s i s t i v i t y i s a v a i l a b l e on t h i s p a r t i c u l a r polymer a l t h o u g h upon s u r v e y i n g s e v e r a l e t h e r p o l y i m i d e s f r o m i n d e p e n d e n t s o u r c e s we m e a s u r e d s i m i l a r v o l u m e r e s i s t i v i t i e s . 1


6.

TAYLOR ET AL.

Metal Ions in

79

Polyimides

Incorporation of A l ( a c a c ) into thepolyimide disappointingly shows no s i g n i f i c a n t r e d u c t i o n i n v o l u m e r e s i s t i v i t y r e l a t i v e to t h e polymer alone. R e p l i c a t e m e a s u r e m e n t s (1.59 x 1 0 - ^ and 1.12 x 1016 ohm-cm) o n two i n d e p e n d e n t l y c a s t f i l m s s u p p o r t t h i s conclusion. R e o r i e n t a t i o n o f t h e same f i l m i n t h e e l e c t r o d e assembly y i e l d e d i d e n t i c a l r e s u l t s s u g g e s t i n g u n i f o r m behavior t h r o u g h o u t t h e f i l m c o n t a i n i n g Al(acac)«. S i m i l a r r e s u l t s w e r e o b t a i n e d o n NiCl«6H 0 f i l l e d p o l y i m i d e s . ( T a b l e V) 3

2


Table V 1

R e s i s t i v i t y D a t a o n BTDA-m,m -DABP P o l y i m i d e Film

Volume R e s i s t i v i t y

(ohms-cm) ,

Polymer

1

,

J

P o l y m e r + N i C l • 6H 0

Metal

Content

6

1.36 x 10,16 2.32 x 10

Polymer + A l ( a c a c )

Films

-

15

1.59 x 10,16 1.92 x 10

1.8% A l 2.9% A l

1.66 x 10, 1.27 x 10,16

0.9% N I

1

6

E l e c t r i f i c a t i o n P e r i o d = 1 m i n u t e @ 500 v o l t s ' S o l v e n t = DMAC S u r f a c e r e s i s t i v i t y measurements w e r e c a r r i e d o u t , b u t t h e r e i s c o n s i d e r a b l e s c a t t e r i n t h e measurements. Other w o r k e r s have a l s o noted greater u n c e r t a i n t i e s a s s o c i a t e d w i t h surface r e s i s t i v i t y measurements r e l a t i v e t o volume r e s i s t i v y measurements A g a i n , t h e A l ( a c a c ) ^ and NiCl »6H 0 c o n t a i n i n g f i l m s e x h i b i t a s u r f a c e r e s i s t i v i t y s i m i l a r t o t h e average o f t h e three data p o i n t s o b t a i n e d f o r "polymer alone" f i l m s . Numerous e f f o r t s t o prepare high q u a l i t y f i l m s i n c o r p o r a t i n g other metal ions i n t o BTDA + m,m -DABP o r p,p -DABP w e r e n o t s a t i s f a c t o r y b e c a u s e m e t a l i o n a d d i t i o n r e s u l t e d i n a decrease i n s o l u t i o n v i s c o s i t y l e a d i n g t o u n s a t i s f a c t o r y f i l m s i n s o f a r as r e s i s t i v i t y measurements a r e c o n c e r n e d . These r e s u l t s s u g g e s t t h a t d u r i n g t h e f i l m c u r i n g p r o c e s s , t h e n o n - c o n d u c t i n g A l ( a c a c ) ^ and N i C l ^ m a i n t a i n t h e i r i n t e g r i t y r a t h e r t h a n b e i n g c o n v e r t e d t o t h e more c o n d u c t i v e a l u m i n u m o r n i c k e l metal as o r i g i n a l l y e n v i s i o n e d . X-ray p h o t o e l e c t r o n s p e c t r o s c o p i c (XPS) d a t a o n t h e A l ( a c a c ) ^ c o n t a i n i n g p o l y i m i d e e m p l o y i n g a magnesium anode s u g g e s t s one t y p e o f a l u m i n u m s p e c i e s , F i g u r e 2. A b i n d i n g e n e r g y o f 118.4 eV f o r A l 2si/2 i s determined based on an ' i n t e r n a l carbon c a l i b r a t i o n C l s - ^ ^ assumed t o be 284.0 eV. T h i s v a l u e o f 118.4 eV c o u p l e d w i t n t h e f a c t s t h a t ( 1 ) no change i n b i n d i n g e n e r g y i s f o u n d f o r 2

f

2

!



80


123

121

119

117

BINDING

115

113

ENERGY

III

(ev)

AI(Qcac) + BTDA +m,m'- DABP 3

Figure 2.

X-ray photoelectron spectrum (Al 2s ) of BTDA + m,m -DABP Al(acac) polymer film (B.E. = 118.4 eV) 1/2

f

3


+


6.

TAYLOR ET AL.

•

1

878

i

1

876

•

874

Metal Ions in

i

i

872

i

i

i

870

i

868

81

Polyimides

i

i

866

i

i

i

864

i

862

i

1

860

1

I

858

I

1 L

856

BINDING ENERGY (ev) Figure 3. X-ray photoelectron spectrum (Ni 2p / ) of BTDA + mjm'-DABP + NiCl • 6 H 0 polymer film (B.E. = 855.7 eV, 873.3 eV) 1/2

2

3

2

2



82


oxygen or nitrogen in the polyimide and (2) the binding energy of Al 2si/2 in Al(acac)3 * s H7.9 e V indicates that aluminum continues to be bound to acetylacetone in the polyimide. An examination of XPS data obtained on the MCI2 containing polyimide, Figure 3, leads to a similar conclusion (Ni 2p^/2 = 854.2 eV in the polyimide, Ni 2p3/2 = 855.0 eV in NiCl 2 . The smaller intensity peak centered around 862 eV is the 2p^/2 satellite photopeak which again is indicative of nickel(II) . Further work in this area is underway employing polyamic acid systems which are known to produce higher viscosity solutions (e.g. polyimides derived from 4,4f-oxydianiline and either BTDA or pyromellitic dianhydride). This is being carried out in the belief that higher viscosity solutions will give rise to higher quality, less brittle films and will, thereby, enable a broader spectrum of metal systems to be studied regarding the adhesive and electrical conductance properties of metal ion filled polyimides. Acknowledgment - Informative discussions regarding this work with T. L. St. Clair are gratefully appreciated. We also wish to thank Robert Ely for technical assistance. References 1. 2. 3.

E. P. Otocha, J. Macromol. Sci., Sci., C5, 275 (1971). A. Eisenbert, Macromolecules, 4 125 (1971). J. Moacanin and E. F. Cuddihy, J. Polym. Sci. C, 14, 313 (1966). 4. M. Yokoyama, H. Ishihara, R. Iwamoto and H. Tadokoro, Macromolecules, 2, 184 (1969). 5. M. J. Hannon and K. F. Wissbrun, J. Polym. Sci. Polym. Phys. Ed., 13, 113 (1975). 6. M. J. Hannon and K. F. Wissburn, J. Polym. Sci. Polym., Phsy. Ed., 13, 223 (1975). 7. B. Valenti, E. Bianchi, G. Greppi, A. Tealdi and A. Ciferri, J. Phys. Chem. 77, 389 (1973). 8. D. Acierno, E. Bianchi, A. Ciferri, B. DeCindio, C. Migliaresi and L. Nicolais, J. Polym. Sci., Symposium No. 54, 259 (1976). 9. R. E. Wetton, D. B. James and W. Whiting, Polym. Letters Ed., 14, 577 (1976). 10. R. J. Angelo and E. I. duPont deNemours & Co., U.S. Patent, No. 3, 073, 785 (1959). 11. Private Communication, R. J. Angelo. 12. H. A. Burgman, J. H. Freeman, L. W. Frost. G. M. Bower, E. J. Traynor and C. R. Ruffing, J. Appl. Polym. Sci., 12, 805 (1968). 13. T. L. St. Clair and D. J. Progar, Polymer Preprints, 16(1) 538 (1975). 14. D. J. Progar and T. L. St. Clair, 7th National SAMPE Technical Conference, Albuquerque, NM Oct., 1975. RECEIVED

July 12, 1979.


Modification of Polymers - American Chemical Society

Recommend Documents