Gas Permeation Chromatography—Viscometry of Polystyrene

Oct 2, 1987 - An IBM PC data system with software is also provided (5). The software acquires data from both detectors, and performs. View: Hi-Res PDF...
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Chapter 7

Gas Permeation Chromatography—Viscometry of Polystyrene Standards in Tetrahydrofuran 1

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M . A . Haney , John E. Armonas , and L Rosen

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Viscotek Corporation, 1030 Russell Drive, Porter, T X 77365 Modchrom, Inc., 8666 Tyler Boulevard, Mentor, OH 44060 Pressure Chemical Company, 3419 Smallman, Pittsburgh, PA 15201 2

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Studies of polystyrene standards in THF solvent are not uncommon. However, bothersome discrepancies still exist in the literature and in practice. For example, the published Mark-Houwink parameters are in wide disagree­ ment (1). The purpose of this work is to examine a large number of PS standards from multiple suppliers, covering a wide range of molecular weights. The i n t r i n s i c v i s c o s i t i e s and GFC retention volumes have been measured and used independently to correlate and crosscheck the molecular weights provided by the suppliers. EXPERIMENTAL

The size exclusion chromatography for this study was done in the routine manner execept for the inclusion of an on­ line viscosity detector called a Differential Viscometer (3) (Viscotek Corp., Porter, Texas, USA). This instru­ ment together with an R1 concentration detector permits the calculation of intrinsic viscosities across the chromatogram. An IBM PC data system with software is also provided (5). The software acquires data from both detectors, and performs calculations of intrinsic viscosity and molecular weight distributions using the Universal Calibration Method. Columns: So1 v e n t : Flow r a t e : Temperature : Pump : Injector :

Two M o d c h r o m M i x e d B e d S t y r e n e d i ν i n y 1benzene 5 m i c r o n G e l THF (stabilized) .1.5 m 1 / m i η 30 C K n a u e r M o d e l 64 Rheodyne M 7 1 2 5 , f i x e d 50 u l l o o p

0097-6156/87/0352-0119$06.00/0 © 1987 American Chemical Society

Provder; Detection and Data Analysis in Size Exclusion Chromatography ACS Symposium Series; American Chemical Society: Washington, DC, 1987.

d e t e c t i o n and

120

Sample? Cone

Co ne

for M , for

De t e c t ο r :

Viscosity

Detector :

D a t. a A c g u ι s ι t ι ο η :

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Provder; Detection and Data Analysis in Size Exclusion Chromatography ACS Symposium Series; American Chemical Society: Washington, DC, 1987.

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DETECTION A N D DATA ANALYSIS IN SIZE EXCLUSION CHROMATOGRAPHY

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Table

III.

Effect Wat r o w

Sample: one

(% w/v)

0.50 0,25 0.10 0.05 0.025

o f Sample C o n c e n t r a t i o n Standards

PC-30126 Pet.Vol.

M =

on

Retentioi

168,000

(ml)

13.03 12.91 12.85 12.82 12.82

Provder; Detection and Data Analysis in Size Exclusion Chromatography ACS Symposium Series; American Chemical Society: Washington, DC, 1987.

H A N E Y ET A L .

GPC- Viscometry of Polystyrene Standards

129

Standards frοm 3 d i f f e r e n t sources c ο r r e l a t e with each other f a i r l y w e l l . C a r e must be t a k e n n o t to r e 1 y ο η 1 y ο n t h e b o t t l e ν a 1 u e s f o r s t - « r-, d a r" d mo 1 e c u I a r we ι q h t s . intrinsic v i s c o s i t y d e t e r m i n a t i o n s n o u 1 -Λ b e a q u ι c ia n d r e 1 ι a b 1 e m e t h o d f o r d e t e r m ι η ι n g t h e? m ο 1 e c u i a r w e ι g n t s ο f n a r r ο w ρ ο 1 y s t y r e n e s t a n d a r- d s . r

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C a u t i ο n m u s t b e e χ e r c ι s e d ι n m a k i r. rj u ρ n a r ο w s t a n d a r d s t ο a v o i d c ο n c. e n t r a t. ι ο n e f f e c t s υ ρ ο n r e t en t ι ο n . T h e Un ι ν e r s a i C a l .i b r a r. ι ο n m e t h ο d ι s c. a ρ a b 1 e ο f ρ r ο ν ι d ι ri g a c c u r a t e ν a 1 u e s ο f m ο 1 e c u 1 a r w e ι g h t d ι -s t r i b ». t i o n a s w e l l a s l i a r k - H o u w i nk p a r aine t e r s f r o m b r o a d d ι s t r ι bu t i ο n sa mρ 1 e s .

REFERENCES

1.

Yau, W.W., Kirkland, J . J . , and Bly, D.D., "Modern Size-Εxclusiοn Liquid Chrοmatοgraρhy". John Wiley & Sons (1979), p. 2 5 2 .

2.

Haney, M.Α., J.Appl.Poly.Sci., 30, 3023-3036

3.

Haney, M.A., J.Appl.Poly.Sci., 30, 3037-3049 (1985).

4.

Bohdanecky, M., and Koνar, J., "Viscosity of Polymer Solutions", Elsevier (1982), p. 9 5 .

5.

Styring, M.G., Armonas, J . E . , and Hamielec, A.E., J.Liq.Chrom., to be published (1987).

RECEIVED

April 22, 1987

Provder; Detection and Data Analysis in Size Exclusion Chromatography ACS Symposium Series; American Chemical Society: Washington, DC, 1987.

(1985).