PREFACE
TODAY'S P O L Y M E R S C I E N T I S T makes use of a large a r r a y of c h a r a c t e r i z a t i o n -•-methods
to
develop
data relating the performance
of
polymeric
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m a t e r i a l s to c h e m i c a l a n d p h y s i c a l structure. P o l y m e r a p p l i c a t i o n s
de-
m a n d c o n f l i c t i n g p e r f o r m a n c e characteristics: strong a d h e s i o n w i t h easy p e e l , hardness w i t h r e s i l i e n c y , f l e x i b i l i t y w i t h d i m e n s i o n a l s t a b i l i t y , i n e r t ness w i t h m i s c i b i l i t y , smoothness w i t h p a i n t a b i l i t y , r i g i d i t y w i t h l a c k of brittleness, a n d c r a c k resistance. T h e d e s i r e d properties are o b t a i n e d b y t h e selection of c h e m i c a l c o m p o s i t i o n , i n c l u d i n g r e s i d u a l or g r a f t e d f u n c t i o n a l groups. C o n t r o l of properties c a n be exercised b y a l t e r n a t i n g structures, b y a l t e r n a t i n g c l u m p s of
f u n c t i o n a l groups
or b y
synthesizing
i n t e r p e n e t r a t i n g p o l y m e r n e t w o r k s . S o m e properties a r e c o n t r o l l e d
by
m o l e c u l a r d i m e n s i o n s : l i n e a r , b r a n c h e d , c r o s s - l i n k e d . O t h e r s are c o n t r o l l e d by molecular
size, b y
c u r i n g conditions
a n d c r o s s - l i n k i n g agents,
by
b l e n d i n g a n d b y a d d i t i v e s i n c l u d i n g p l a s t i c i z e r s , a n t i o x i d a n t s , surfactants, stabilizers, a n d The
fillers.
characterization
and
resultant
systems r e q u i r e i n p u t f r o m m a n y
fields:
understanding chromatography,
r h e o l o g y , surface c h e m i s t r y , e l e c t r o n m i c r o s c o p y ,
of
polymeric
spectroscopy,
t h e r m a l analysis, a n d
p h y s i c a l testing. O t h e r h i g h l y s p e c i a l i z e d techniques i n v o l v e l i g h t scatt e r i n g , n e u t r o n scattering, e x c i m e r
fluorescence,
photoacoustic
copy,
w i t h exact
i d e n t i f i c a t i o n of
and
pyrolytic
degradation,
m o l e c u l a r subunits b y c h r o m a t o g r a p h y
combined
spectros-
w i t h I R and
small mass
spectrometry. I n d r a w i n g u p o n so m a n y diverse a n d s p e c i a l i z e d
fields,
polymer
c h a r a c t e r i z a t i o n has p r o f i t e d b y t h e c r o s s - f e r t i l i z a t i o n of ideas that o c c u r w h e n specialists m e e t a n d c o m m u n i c a t e w i t h one another. S e r v i n g this p u r p o s e , the A m e r i c a n C h e m i c a l Society D i v i s i o n s of O r g a n i c C o a t i n g s and
Plastics Chemistry, P o l y m e r Chemistry, R u b b e r Chemistry, C o l l o i d
Chemistry, and Cellulose and Paper Chemicals
h o l d cosponsored sym-
p o s i a at the N a t i o n a l A C S meetings. T h e M a c r o m o l e c u l a r
Secretariat,
a p r o g r a m m i n g g r o u p c o m p o s e d of a l l five d i v i s i o n s , d e s i g n a t e d P o l y m e r C h a r a c t e r i z a t i o n as its t o p i c for 1981, a n d w i t h the p a r t i c i p a t i o n of the D i v i s i o n of A n a l y t i c a l C h e m i s t r y , p r o g r a m m e d a f u l l week's organized
a n d c h a i r e d b y the editor. T h i s book, c o v e r i n g
symposium significant
advances i n p o l y m e r c h a r a c t e r i z a t i o n , is b a s e d o n t h a t s y m p o s i u m . I t is xi Craver; Polymer Characterization Advances in Chemistry; American Chemical Society: Washington, DC, 1983.
o r g a n i z e d a r o u n d seven m a j o r m e t h o d s w i t h single chapters o n a
few
n e w or h i g h l y s p e c i a l i z e d t e c h n i q u e s . C o m p r e h e n s i v e c o v e r a g e of d y n a m i c m e c h a n i c a l m e t h o d s is p r o v i d e d i n n i n e c h a p t e r s b y experts selected b y t h e 1978 B o r d e n A w a r d w i n n e r , J o h n K . G i l l h a m , of P r i n c e t o n U n i v e r s i t y . T h e latest d e v e l o p m e n t s
in
a u t o m a t i o n of e q u i p m e n t for d y n a m i c m e c h a n i c a l spectroscopy, t o r s i o n p e n d u l u m a n d t o r s i o n a l b r a i d analyses, a n d shear i n p o l y m e r melts are reported. Applications include impregnated
c l o t h analysis, m e c h a n i c a l
analysis of o r g a n i c coatings, a n d strength a n d viscoelastic c h a r a c t e r i z a t i o n of p o l y m e r i c solids.
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T h e t h e r m a l characteristics of p o l y m e r s bear i m p o r t a n t r e l a t i o n s h i p s to t h e i r p e r f o r m a n c e . T h e r m a l g r a v i m e t r i c analysis ( T G A ) m a y b e u s e d for
identification or
determination
of
p u r i t y of
polymers.
TGA
can
m e a s u r e solvent r e t e n t i o n a n d p r o v i d e a c t i v a t i o n energies a n d heats of reactions. describes
B e r n h a r d W u n d e r l i c h , of
Rensselaer
Polytechnic
Institute,
sources of e x p e r i m e n t a l errors i n d i f f e r e n t i a l s c a n n i n g c a l o r i -
m e t r y ( D S C ) a n d s u m m a r i z e s the state of the art i n i n s t r u m e n t a t i o n . T h e t r e a t m e n t of k i n e t i c d a t a a n d k i n e t i c m o d e l i n g , i n c l u d i n g a p p l i c a t i o n s to p o l y m e r d e g r a d a t i o n , is r e p o r t e d b y J . F l y n n a n d B . D i c k e n s of N a t i o n a l B u r e a u of S t a n d a r d s . A p p l i c a t i o n to coatings investigators
from
Glidden
Coatings
and
Resins
is r e p o r t e d
D i v i s i o n of
the by
SCM
Corporation. C h r o m a t o g r a p h i c m e t h o d s of p o l y m e r f r a c t i o n a t i o n a n d the resultant c o r r e l a t i o n of c h r o m a t o g r a m s w i t h p o l y m e r c o m p o s i t i o n a n d
performance
are a m o n g t h e most w i d e l y u s e d methods of c h a r a c t e r i z a t i o n . H o w e v e r , the d a t a m u s t be i n t e r p r e t e d c a u t i o u s l y because m a n y v a r i a b l e s affect p o l y m e r d i s t r i b u t i o n as reflected b y c h r o m a t o g r a m s .
A m o n g these
are
n o n u n i f o r m i t y of c h e m i c a l c o m p o s i t i o n of the v a r i o u s p a r t i c l e size ranges w h i c h i n t u r n affect s o l u b i l i t i e s a n d d e t e c t o r response. T h e c o v e r a g e of this subject as a r r a n g e d b y
T h e o d o r e P r o v d e r , of
S C M Corporation,
i n c l u d e s the t h e o r y a n d u n d e r s t a n d i n g of c a l i b r a t i o n p r o b l e m s of p o l y m e r chromatography
a n d techniques
for m i n i m i z i n g them. N o v e l partition
m e t h o d s s u c h as f o a m f r a c t i o n a t i o n are also p r e s e n t e d . Studies of p o l y m e r surfaces b y s c a n n i n g electron m i c r o s c o p y
alone
a n d i n c o m b i n a t i o n w i t h x-ray analysis a n d m i c r o - R a m a n t e c h n i q u e s is especially
useful
i n organic
coatings
analysis
and
research.
Results
r e p o r t e d here i n c l u d e i n v e s t i g a t i o n of m i l d e w attack o n p a i n t surfaces a n d c o r r o s i o n of m e t a l substrates i n m i c r o s c o p i c - s i z e d c o a t i n g - m e t a l interface. R a m a n m i c r o p r o b e ,
blisters at t h e
M O L E , permits
chemical
analysis of microareas. A n e x a m p l e of its usefulness is the i d e n t i f i c a t i o n of "fisheyes"
i n a copolymer
sheet as b e i n g h o m o p o l y m e r
impurities.
T h e c a p a b i l i t y of c o r r e l a t i n g m e t a l analysis f r o m x-ray m a p s of with
organic
analysis b y
R a m a n microprobe
makes
these
surfaces combined
xii Craver; Polymer Characterization Advances in Chemistry; American Chemical Society: Washington, DC, 1983.
techniques a p o w e r f u l research tool. L . H . P r i n c e n , U S D A ,
organized
a n a p p l i c a t i o n - o r i e n t e d r e p o r t o n these significant i n s t r u m e n t a l advances. N e a r l y h a l f of the chapters i n this b o o k r e p o r t o n advances i n t h e use of spectroscopy for p o l y m e r c h a r a c t e r i z a t i o n . T h e s e tools are o f t e n c o m b i n e d , not o n l y w i t h e a c h other, b u t w i t h t h e r m a l a n d m e c h a n i c a l t e c h n i q u e s to r e l a t e m o l e c u l a r s t r u c t u r e to p o l y m e r p e r f o r m a n c e
and
stability. E . B r a m e , d u P o n t , has p r o v i d e d a n o v e r v i e w of N M R a p p l i c a t i o n s . Advances i n
1 3
C N M R , m a d e p o s s i b l e b y the i n c r e a s e d s e n s i t i v i t y of
pulsed F o u r i e r transform instruments, provide i m p r o v e d determination Downloaded by 80.82.77.83 on December 27, 2017 | http://pubs.acs.org Publication Date: June 1, 1983 | doi: 10.1021/ba-1983-0203.pr001
of t a c t i c i t y , c o m o n o m e r s e q u e n c e a n d b r a n c h i n g of s y n t h e t i c p o l y m e r s . T h e r e are five f u l l chapters r e p o r t i n g o n advances i n p o l y m e r s t r u c t u r e determination by N M R including Ή ,
1 3
C , and
1 9
F . T h e chapter authored
b y F r a n k B o v e y , of B e l l L a b o r a t o r i e s , is r i c h i n i n t e r p r e t a t i o n of
the
significance of N M R d a t a as a p p l i e d to p o l y m e r synthesis, s t a b i l i t y , a n d m o r p h o l o g y . P r a c t i c a l use of s o p h i s t i c a t e d s t r u c t u r a l analysis arises f r o m such
findings
as t h e d e t e c t i o n of t e r t i a r y c h l o r i d e atoms i n p o l y ( v i n y l
c h l o r i n e ) w h i c h m a y c o n t r i b u t e to its t h e r m a l i n s t a b i l i t y . N M R is u s u a l l y c a r r i e d out o n p o l y m e r s i n s o l u t i o n or i n t h e m o l t e n state. O n l y l o w r e s o l u t i o n or b r o a d l i n e N M R has b e e n a t t a i n a b l e o n solids. R e c e n t advances i n m a g i c - a n g l e s p i n n i n g a n d d i p o l a r d e c o u p l i n g a l o n g w i t h m u l t i p u l s e N M R h a v e m a d e i t possible to resolve i n d i v i d u a l resonances of s o l i d state samples. R e s e a r c h d i r e c t e d t o w a r d d e s c r i b i n g the s e g m e n t a l m o t i o n s i n a m o r p h o u s a n d s e m i c r y s t a l l i n e p o l y m e r s a n d u n d e r s t a n d i n g secondary transitions makes use of these N M R t e c h n i q u e s a p p l i e d to samples at v a r y i n g temperatures. I R spectroscopy has l o n g b e e n a v a l u a b l e t o o l f o r c h e m i c a l c h a r a c t e r i z a t i o n of p o l y m e r s a n d for f o l l o w i n g t h e c h e m i c a l changes i n c u r i n g o r d e g r a d a t i o n reactions. T h e i n c r e a s e d s e n s i t i v i t y n o w o b t a i n a b l e f r o m c o m p u t e r a v e r a g i n g of d a t a a n d the i n c r e a s e d s p e e d of d e t e r m i n i n g a s p e c t r u m m a d e possible b y F o u r i e r t r a n s f o r m are e x p a n d i n g the a p p l i c a tions of I R to m i n o r c o m p o s i t i o n surfaces
differences
a n d to c o n f o r m a t i o n
a n d i n b u l k samples u n d e r stress. J . K o e n i g , C a s e
at
Western
R e s e r v e U n i v e r s i t y , a r r a n g e d the coverage of this subject a n d i n c l u d e d advances i n the t h e o r y of I R intensities a n d d e v e l o p m e n t s i n p h o t o a c o u s t i c spectroscopy. A d v a n c e s i n t h e t e c h n i q u e s f o r o b s e r v i n g m i c r o s t r u c t u r a l changes b y I R d a t a s i m u l t a n e o u s l y w i t h s t r e s s - s t r a i n d a t a are d e s c r i b e d b y S. L . H s u a n d D . J . B u r c h e l l , U n i v e r s i t y of Massachusetts. D e g r a d a t i o n studies of p o l y ( e t h y l e n e t e r e p h t h a l a t e )
a n d p o l y a c r y l o n i t r i l e p o l y m e r s are r e
p o r t e d b y B . B u l k i n , E . P e a r c e , a n d C . C h e n , of t h e P o l y t e c h n i c I n s t i t u t e of N e w Y o r k , a n d M . C o l e m a n a n d G . S i v y of P e n n s y l v a n i a State U n i versity, respectively. James B o e r i o , U n i v e r s i t y of C i n c i n n a t i , xiii Craver; Polymer Characterization Advances in Chemistry; American Chemical Society: Washington, DC, 1983.
describes
r e f l e c t i o n / a b s o r p t i o n spectra s h o w i n g p o l y m e r o r i e n t a t i o n at interfaces of u l t r a t h i n coatings o n p o l i s h e d m e t a l surfaces. A d v a n c e s i n the a p p l i c a t i o n of p h o t o a c o u s t i c F o u r i e r t r a n s f o r m I R to p o l y m e r analysis is discussed b y W a r r e n V i d r i n e of N i c o l e t Instruments. M a j o r advances h a v e b e e n m a d e i n the last f e w years i n t h e t h e o r y of I R a n d R a m a n intensities. A w e a l t h of m o l e c u l a r structure i n f o r m a t i o n is a v a i l a b l e f r o m
absolute
b a n d intensities, b u t spectroscopists
have
l a c k e d the t h e o r e t i c a l tools to i n t e r p r e t the significance of these intensities. The manuscript contributed by
G i u s e p p e Z e r b i , of
Istituto C h i m i c a ,
M i l a n , I t a l y , describes advances i n this field. T h i s c o n t r i b u t i o n p r o v i d e s Downloaded by 80.82.77.83 on December 27, 2017 | http://pubs.acs.org Publication Date: June 1, 1983 | doi: 10.1021/ba-1983-0203.pr001
examples t h a t demonstrate the significance of the b r e a k t h r o u g h i n t h e o r y to the u n d e r s t a n d i n g of m o l e c u l a r structure of p o l y m e r s . O t h e r
new
areas r e p o r t e d b y D r . Z e r b i d e a l w i t h t h e c a l c u l a t i o n of v i b r a t i o n a l frequencies of v e r y large m o l e c u l e s w i t h no s y m m e t r y a n d the d e t e r m i n a t i o n of c h a i n lengths f r o m the L o n g i t u d i n a l A c o u s t i c M o d e
(LAM).
I m p r o v e m e n t s i n t e c h n i q u e s for p y r o l y t i c d e g r a d a t i o n of p o l y m e r s into r e p r o d u c i b l e fragments t h a t c a n be a n a l y z e d b y gas c h r o m a t o g r a p h y a n d mass spectrometry p e r m i t a t o m - b y - a t o m m o l e c u l a r arrangements to be i d e n t i f i e d . T h e coverage of a n a l y t i c a l p y r o l y s i s w a s o r g a n i z e d
by
S h i r l e y L i e b m a n , of C h e m i c a l D a t a Systems, I n c . S. T s u g e , of N a g o y a U n i v e r s i t y , J a p a n , discusses t h e f u n d a m e n t a l c o n d i t i o n s for o b t a i n i n g characteristic a n d r e p r o d u c i b l e h i g h - r e s o l u t i o n p y r o g r a m s a n d the a p p l i c a t i o n to sequence d i s t r i b u t i o n i n v e s t i g a t i o n i n c o p o l y m e r s . T h e specificity of laser sources a n d the usefulness of b e i n g able to v a r y p o w e r densities is d e m o n s t r a t e d i n the r e p o r t b y D a v i d H e r c u l e s et a l . , U n i v e r s i t y of P i t t s b u r g h , o n laser m i c r o p r o b e mass analysis ( L A M M A ) . T h e s e t e c h n i q u e s are a p p l i c a b l e to d i v e r s e m a c r o m o l e c u l e s . C o a l c h a r a c t e r i z a t i o n is r e p o r t e d b y K . V o o r h e e s a n d c o w o r k e r s , C o l o r a d o S c h o o l of M i n e s . F o r r e s t B a y e r p r o v i d e s a n o v e r v i e w of the specificity a n d s e n s i t i v i t y of these t e c h n i q u e s to a w i d e r a n g e of b i o p o l y m e r s . E . R e i n e r a n d F . M o r a n , of G e o r g i a I n s t i t u t e of T e c h n o l o g y , c h a r a c t e r i z e details of
pathogenic
m i c r o o r g a n i s m s a n d m a m m a l i a n cells i n c l u d i n g ones reflecting defects w h i c h m a y p r o d u c e disease s u c h as cystic
genetic
fibrosis.
L a r r y B r y d i a , of U n i o n C a r b i d e , r e p r e s e n t e d the A n a l y t i c a l D i v i s i o n a n d served as c h a i r m a n for s p e c i a l i z e d t e c h n i q u e s . T w o subjects
from
that s y m p o s i u m t h a t are c o v e r e d i n single chapters are advances i n scattering t e c h n i q u e s b y R . S. S t e i n , U n i v e r s i t y of Massachusetts, a n d the use of e x c i m e r
fluorescence
as a p r o b e of p o l y m e r structure b y C . W .
F r a n k of S t a n f o r d U n i v e r s i t y . I a m i n d e b t e d to t h e subject c h a i r m e n a n d the authors for p r o v i d i n g w e l l - b a l a n c e d c o v e r a g e i n e a c h field. T h e y h a v e i n c l u d e d advances i n t h e o r y a l o n g w i t h e x p e r i m e n t a l details essential for o b t a i n i n g g o o d d a t a . T h e p r a c t i c a l v a l u e of the results f r o m these m a j o r m e t h o d s of c h e m i c a l xiv Craver; Polymer Characterization Advances in Chemistry; American Chemical Society: Washington, DC, 1983.
a n d p h y s i c a l c h a r a c t e r i z a t i o n of p o l y m e r s has b e e n i n t e r p r e t e d i n terms of s t a b i l i t y a n d p e r f o r m a n c e of the m a n y p o l y m e r s w h i c h w e r e i n v e s t i g a t e d . I a m e s p e c i a l l y g r a t e f u l to a l l o f t h e m f o r t h e i r c o o p e r a t i o n a n d p a t i e n c e w h i c h m a d e this b o o k possible.
CLARA
D.
CRAVER
Chemir Laboratories
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G l e n d a l e , MO 63122 N o v e m b e r 1982
xv Craver; Polymer Characterization Advances in Chemistry; American Chemical Society: Washington, DC, 1983.
