title: Characterization of poly(methyl methacrylate)-graft-poly(styrene)s using various chromatographic techniques.
abstract: Two graft copolymer samples of identical average composition were synthesized by grafting living polystyrene anions onto a broadly distributed PMMA backbone. Size exclusion chromatography (SEC) with only RI-detection, SEC with viscometry and light scattering detection, SEC with UV and RI dual detection, gradient chromatography and 2-dimensional chromatography were applied to compare the information that can be obtained by the different techniques. While only limited information was retrieved by conventional SEC or SEC with molar mass sensitive detection, SEC with UV and RI revealed different chemical heterogeneity of the samples. Using gradient chromatography and 2-dimensional chromatography it was possible to identify non-grafted side chains and unreacted parent PMMA besides the actual graft copolymer molecules. While in one sample a heavily grafted product was formed besides non-grafted PMMA, the second sample did not contain ungrafted PMMA but a graft product of lower grafting density. The different product distributions were explained by the different synthetic procedures.
authors: PSS Polymer Standards Service GmbH, 55128 Mainz, Germany.
authors: Ralf
authors: R
authors: Leinweber
authors: PSS Polymer Standards Service GmbH, 55128 Mainz, Germany.
authors: Peter
authors: P
authors: Montag
authors: PSS Polymer Standards Service GmbH, 55128 Mainz, Germany.
authors: Jasmin
authors: J
authors: Preis
authors: PSS Polymer Standards Service GmbH, 55128 Mainz, Germany. Electronic address: wradke@pss-polymer.com.
authors: Wolfgang
authors: W
authors: Radke
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000379:methods*; D002850:Chromatography, Gel; D008970:Molecular Weight; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry*
chemical_list: D011137:Polystyrenes; D019904:Polymethyl Methacrylate
keywords: 2-dimensional chromatography; GPC; Gradient chromatography; Graft-copolymers; SEC; SEC-viscosity