Molecular weights of styrene–maleic anhydride copolymers

Abstract

SynopsisA dual-calibration method for the determination of molecular weights and molecular weight distribution of styrene-maleic anhydride copolymers (S/MA) by gel permeation chromatography (GPC) is introduced. It might be applicable to copolymers of other type. A linear relationship of intrinsic viscosity [77] and weight-average molecular weight (a,) for unfractionated S/MA in tetrahydrofuran (THF) a t 25OC can be expressed by the equationThe maleic anhydride content of the copolymers ranges from 5 to 50 mole-%, and the a, range is from 2 X lo4 to 7 x 106. The plot of log [q] A?, versus GPC elution volume of the S/MA copolymers falls on the same curve as that of the polystyrene standards in THF.

Amphiphilic maleic acid‐containing alternating copolymers—2. Dilute solution characterization by light scattering, intrinsic viscosity, and PGSE NMR spectroscopy

“…The value obtained for M w = 350 kg/mol, is somewhat larger than the M PEOeq = 280 kg/mol determined by SEC (PEO equivalent molecular weight of the parent anhydride polymer listed in Table I). However, considering the fact that SEC in THF is known to give erroneous results for SMA28 and our measured intrinsic viscosity of SMA in THF (0.79 dL/g) suggests a molecular weight of 340 kg/mol for the parent anhydride polymer based on the Mark‐Houwink equation for SMA in THF,27 we would conclude that SMA‐Na does not aggregate in 0.1 N NaAc.…”

“… g The molecular weight in parentheses was calculated from the measured intrinsic viscosity of 0.79 dL/g for SMA‐hmw in THF using the Mark‐Houwink equation for SMA in THF 27. The SEC equivalent molecular weight for SMA‐hmw is most likely erroneous due to the known difficulties with SEC of SMA in THF 28…”

Copolymer analysis

“…[11] = 1.42 x 10-5 M~·9636 (for the copolymer) (S. 26) A dual-calibration method for the determination of molecular mass (M) and MMD of styrene-maleic anhydride copolymers by SEC has been reported [24]. This method was applicable without preparative fractionation for copolymers of broad composition and M ranges.…”

“…Viscosity data and SEC data for these fractions in THF at 20°C were obtained. The Mark-Houwink constants were calculated using eqn (S.24) [21]: 24) where W; and J j are the mass fraction and the product [l1]jMj of the ith species, respectively. When the value of a is correct, a plot of [11] v. Za will lead to a straight line for each value of a.…”

Synthesis and characterization of alkali‐modified styrene‐maleic anhydride copolymer for dispersion of TiO2

“…Chow et al 21 have determined the molecular weight and molecular weight distribution of styrene-maleic anhybride copolymers using gel-permeation chromotography, light-scattering photometry, membrane osmometry, and intrinsic viscosity and have proposed a dual-calibration method for SMA copolymers. According to them, a linear relationship of intrinsic viscosity (Z) and weight average molecular weight (Mw) can be expressed for unfractionated SMA in THF at 258C by the equation Z ¼ 3.98 Â 10 À4 Mw 0.596 , which is valid for SMA having anhydride content in the range of 5-50 mol %.…”