Utility of chromatographic and spectroscopic techniques for a detailed characterization of poly(styrene-b-isoprene) miktoarm star copolymers with complex architecture

Handle URI:
http://hdl.handle.net/10754/562332
Title:
Utility of chromatographic and spectroscopic techniques for a detailed characterization of poly(styrene-b-isoprene) miktoarm star copolymers with complex architecture
Authors:
Šmigovec Ljubič, Tina; Rebolj, Katja; Pahovnik, David; Hadjichristidis, Nikolaos ( 0000-0003-1442-1714 ) ; Žigon, Majda; Žagar, Ema
Abstract:
We analyzed various miktoarm star copolymers of the PS(PI) x type (x = 2, 3, 5, 7), which consist of one long polystyrene (PS) arm (82 or 105 kDa) and various numbers of short polyisoprene (PI) arms (from 11.3 to 39.7 kDa), prepared by anionic polymerization and selective chlorosilane chemistry. The length of the PI arm in stars decreases with the number of arms, so that the chemical compositions of all PS(PI) x samples were comparable. Our aim was to determine the purity of samples and to identify exactly the constituents of individual samples. For this purpose we used a variety of separation techniques (size-exclusion chromatography (SEC), reversed-phase liquid-adsorption chromatography (RP-LAC), and two-dimensional liquid chromatography (2D-LC)) and characterization techniques (UV-MALS-RI multidetection SEC system, NMR, and MALDI-TOF MS). The best separation and identification of the samples' constituents were achieved by RP-LAC, which separates macromolecules according to their chemical composition, and a subsequent analysis of the off-line collected fractions from the RP-C18 column by SEC/UV-MALS-RI multidetection system. The results showed that all PS(PI) x samples contained the homo-PS and homo-PI in minor amounts and the high-molar-mass (PS) y(PI) z (y > 1) species, the content of which is higher in the samples PS(PI) 5 and PS(PI) 7 than in the samples PS(PI) 2 and PS(PI) 3. The major constituent of the PS(PI) 2 sample was the one with the predicted structure. On the other hand, the major components of the PS(PI) x (x = 3, 5, and 7) samples were the stars consisting of a smaller number of PI arms than predicted from the functionalities of chlorosilane coupling agents. These results are in agreement with the average chemical composition of samples determined by proton NMR spectroscopy and characterization of the constituents by MALDI-TOF MS. © 2012 American Chemical Society.
KAUST Department:
Biological and Environmental Sciences and Engineering (BESE) Division; KAUST Catalysis Center (KCC); Physical Sciences and Engineering (PSE) Division; Chemical Science Program; Polymer Synthesis Laboratory
Publisher:
American Chemical Society (ACS)
Journal:
Macromolecules
Issue Date:
25-Sep-2012
DOI:
10.1021/ma3012366
Type:
Article
ISSN:
00249297
Sponsors:
The authors gratefully acknowledge the financial support of the Ministry of Higher Education, Science and Technology of the Republic of Slovenia through (a) the Slovenian Research Agency (Program P2-0145) and (b) the Centre of Excellence - Polymer Materials and Technologies for MALDI-TOF MS analysis.
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Chemical Science Program; KAUST Catalysis Center (KCC); Biological and Environmental Sciences and Engineering (BESE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorŠmigovec Ljubič, Tinaen
dc.contributor.authorRebolj, Katjaen
dc.contributor.authorPahovnik, Daviden
dc.contributor.authorHadjichristidis, Nikolaosen
dc.contributor.authorŽigon, Majdaen
dc.contributor.authorŽagar, Emaen
dc.date.accessioned2015-08-03T10:01:14Zen
dc.date.available2015-08-03T10:01:14Zen
dc.date.issued2012-09-25en
dc.identifier.issn00249297en
dc.identifier.doi10.1021/ma3012366en
dc.identifier.urihttp://hdl.handle.net/10754/562332en
dc.description.abstractWe analyzed various miktoarm star copolymers of the PS(PI) x type (x = 2, 3, 5, 7), which consist of one long polystyrene (PS) arm (82 or 105 kDa) and various numbers of short polyisoprene (PI) arms (from 11.3 to 39.7 kDa), prepared by anionic polymerization and selective chlorosilane chemistry. The length of the PI arm in stars decreases with the number of arms, so that the chemical compositions of all PS(PI) x samples were comparable. Our aim was to determine the purity of samples and to identify exactly the constituents of individual samples. For this purpose we used a variety of separation techniques (size-exclusion chromatography (SEC), reversed-phase liquid-adsorption chromatography (RP-LAC), and two-dimensional liquid chromatography (2D-LC)) and characterization techniques (UV-MALS-RI multidetection SEC system, NMR, and MALDI-TOF MS). The best separation and identification of the samples' constituents were achieved by RP-LAC, which separates macromolecules according to their chemical composition, and a subsequent analysis of the off-line collected fractions from the RP-C18 column by SEC/UV-MALS-RI multidetection system. The results showed that all PS(PI) x samples contained the homo-PS and homo-PI in minor amounts and the high-molar-mass (PS) y(PI) z (y > 1) species, the content of which is higher in the samples PS(PI) 5 and PS(PI) 7 than in the samples PS(PI) 2 and PS(PI) 3. The major constituent of the PS(PI) 2 sample was the one with the predicted structure. On the other hand, the major components of the PS(PI) x (x = 3, 5, and 7) samples were the stars consisting of a smaller number of PI arms than predicted from the functionalities of chlorosilane coupling agents. These results are in agreement with the average chemical composition of samples determined by proton NMR spectroscopy and characterization of the constituents by MALDI-TOF MS. © 2012 American Chemical Society.en
dc.description.sponsorshipThe authors gratefully acknowledge the financial support of the Ministry of Higher Education, Science and Technology of the Republic of Slovenia through (a) the Slovenian Research Agency (Program P2-0145) and (b) the Centre of Excellence - Polymer Materials and Technologies for MALDI-TOF MS analysis.en
dc.publisherAmerican Chemical Society (ACS)en
dc.titleUtility of chromatographic and spectroscopic techniques for a detailed characterization of poly(styrene-b-isoprene) miktoarm star copolymers with complex architectureen
dc.typeArticleen
dc.contributor.departmentBiological and Environmental Sciences and Engineering (BESE) Divisionen
dc.contributor.departmentKAUST Catalysis Center (KCC)en
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentChemical Science Programen
dc.contributor.departmentPolymer Synthesis Laboratoryen
dc.identifier.journalMacromoleculesen
dc.contributor.institutionLaboratory for Polymer Chemistry and Technology, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Sloveniaen
dc.contributor.institutionCentre of Excellence for Polymer Materials and Technologies, Tehnološki Park 24, SI-1000 Ljubljana, Sloveniaen
kaust.authorHadjichristidis, Nikolaosen
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