Thin-Layer Chromatographic Identification of Chain Architectures of Styrene—Butadiene Copolymers

Abstract

ABSTRACT:The feasibilities of thin-layer chromatography as a tool to identify the chain architecture of given copolymer samples have been investigated. To this end, styrene-butadiene (SB) block copolymers with known chain architecture were prepared and used as reference samples. Preliminary TLC experiments on these samples indicated that the random, tapered, diblock and triblock SB-samples could be chromatographically distinguished from one another under suitable development conditions. By applying the procedures thus established, the chain architecture of various commercial SB-products could be identified without appreciable interference from the molecular weight and composition.

Real-time spectral acquisition and size exclusion chromatography combined to give verification of copolymerization and analysis of composition, all as a function of molecular size

“…"This is the expected concentration that should result from 100% hydrolysis. 6 Absorbance of methanol solution after being diluted by a factor of 2.50. c % Yield = [concentration recovered / concentration expected] X 100. "Monomer mole ratio was 0.0504 (this is the ratio of moles of N-substituted amide repeat units to moles of 1-amidoethylene repeat units in the copolymer).…”

“…The hydroperoxide was produced by irradiating oxygen-saturated, 1,4-dioxacyclohexane with a 1000-W Xe lamp. 6 Moles of N-substituted amide/moles, total amide; mole fraction of N-substituted monomer in the reaction mixture.…”

Rubber

“…TLC (thin-layer chromatography) distinguishes styrenebutadiene random, tapered, diblock, and triblock copolymers (55,88). Gradient elution with CHCI3 in CCI4 gives separation according to styrene content while elution mixtures of polar solvent and nonsolvent give separation according to molecular weight (107).…”