Two-Dimensional Chromatography of Complex Polymers, 7 - Detailed Study of Polystyrene-block-Polyisoprene Diblock Copolymers Prepared by Sequential Anionic Polymerization and Coupling Chemistry

2008 ◽  
Vol 209 (19) ◽  
pp. 2026-2039 ◽  
Author(s):  
Valentina Mass ◽  
Vasilios Bellas ◽  
Harald Pasch
Keyword(s):  
Anionic Polymerization ◽  
Diblock Copolymers ◽  
Two Dimensional ◽  
Complex Polymers

scholarly journals Two-dimensional chromatography of complex polymers. 3. Full analysis of polystyrene-poly(methyl methacrylate) diblock copolymers

e-Polymers ◽  
2002 ◽  
Vol 2 (1) ◽  
Author(s):  
Harald Pasch ◽  
Kibret Mequanint ◽  
Adrian Jörg
Keyword(s):  
Block Copolymers ◽  
Methyl Methacrylate ◽  
Diblock Copolymers ◽  
Size Exclusion ◽  
Molecular Heterogeneity ◽  
Two Dimensional ◽  
Poly Methyl Methacrylate ◽  
Mass Distributions ◽  
Exclusion Chromatography ◽  
Complex Polymers

AbstractPoly(styrene-block-methyl methacrylate)s were fully analyzed by liquid chromatography at the critical point of adsorption (LC-CC) and two-dimensional chromatography. Operating at chromatographic conditions corresponding to the critical points of the homopolymers polystyrene and poly(methyl methacrylate), the block lengths distributions for the different blocks of the block copolymers were determined quantitatively. Information on the amounts and molar mass distributions of homopolymers and coupling products that were identified in the samples as by-products was obtained by on-line coupled 2D chromatography. It was shown that a complete picture of the molecular heterogeneity of block copolymers can be obtained only when information from different chromatographic experiments is combined. Size exclusion chromatography alone is inappropriate for evaluating the molecular heterogeneity of such samples.

scholarly journals A controlled synthesis method of alkyl methacrylate block copolymers via living anionic polymerization at ambient temperature

RSC Advances ◽  
2019 ◽  
Vol 9 (28) ◽  
pp. 16049-16056 ◽  
Author(s):  
Zheng Li ◽  
Jianding Chen ◽  
Guijin Zou ◽  
Tongyuan Zhang ◽  
Dafu Wei ◽  
...  
Keyword(s):  
Block Copolymers ◽  
Ambient Temperature ◽  
Anionic Polymerization ◽  
Diblock Copolymers ◽  
Synthesis Method ◽  
Controlled Synthesis ◽  
Living Anionic Polymerization ◽  
Alkyl Methacrylate ◽  
High Yields

A series of well-defined diblock copolymers containing PMMA, PEMA and PBMA blocks were synthesized with narrow MWDs and high yields via anionic polymerization, while t-BuOK was selected as initiator in THF at 0 °C. .

Side-Chain LC Block Copolymers with Well Defined Structures Prepared by Living Anionic Polymerization. 2: Effect of the Glass Transition Temperature of Amorphous Segments on the Phase Behaviour and Structure of the LC Segment

1998 ◽  
Vol 10 (1) ◽  
pp. 131-138 ◽  
Author(s):  
Masayuki Yamada ◽  
Tomomichi Itoh ◽  
Akira Hirao ◽  
Sei-Ichi Nakahama ◽  
Junji Watanabe
Keyword(s):  
Glass Transition ◽  
Anionic Polymerization ◽  
Diblock Copolymers ◽  
Domain Size ◽  
Phase Behaviour ◽  
Side Chain ◽  
Isotropic Phase ◽  
Transition Temperatures ◽  
Living Anionic Polymerization ◽  
Methyl Styrene

We have prepared two classes of LC diblock copolymers, OcSt-b-LC and MeStb-LC, by living anionic polymerization. These are composed of the side-chain LC polymer as one segment and two different amorphous polymers, poly(octyl styrene) (OcSt) and poly(α-methyl styrene) (MeSt), as the other segment. OcSt and MeSt segments have glass transition temperatures of −60 °C and 160 °C respectively, which are relatively lower and higher than the transition temperatures of crystal–SA (∼90 °C) and SA–isotropic (∼130 °C) in the LC segment. In OcSt-b-LC the lamellar domain size decreases gradually from that of the crystal phase to that of the isotropic phase, indicating that the global conformation of the backbone changes throughout the SA temperature region. In MeSt-b-LC, in contrast, no change in the lamellar size is observed and the crystallinity of the LC segment is reduced in comparison with that in OcSt-b-LC while the liquid crystal is well formed. Such a distinction between two copolymer systems, arising from an interplay between the LC and amorphous segments, shows that the global conformation of the backbone is significant for understanding the phase behaviour and structure of side-chain LC polymers.

Crystallization-Driven Two-Dimensional Nanosheet from Hierarchical Self-Assembly of Polypeptoid-Based Diblock Copolymers

2018 ◽  
Vol 51 (16) ◽  
pp. 6344-6351 ◽  
Author(s):  
Zhekun Shi ◽  
Yuhan Wei ◽  
Chenhui Zhu ◽  
Jing Sun ◽  
Zhibo Li
Keyword(s):  
Self Assembly ◽  
Diblock Copolymers ◽  
Two Dimensional

Two‐dimensional chromatography of complex polymers, 8. Separation of fatty alcohol ethoxylates simultaneously by end group and chain length

2010 ◽  
Vol 33 (10) ◽  
pp. 1375-1381 ◽  
Author(s):  
Jacques‐Antoine Raust ◽  
Adele Bruell ◽  
Pritish Sinha ◽  
Wolf Hiller ◽  
Harald Pasch
Keyword(s):  
Chain Length ◽  
Fatty Alcohol ◽  
Alcohol Ethoxylates ◽  
Two Dimensional ◽  
Complex Polymers ◽  
End Group

scholarly journals Phosphonium-containing diblock copolymers from living anionic polymerization of 4-diphenylphosphino styrene

2016 ◽  
Vol 52 (5) ◽  
pp. 950-953 ◽  
Author(s):  
Alison R. Schultz ◽  
Gregory B. Fahs ◽  
Chainika Jangu ◽  
Mingtao Chen ◽  
Robert B. Moore ◽  
...  
Keyword(s):  
Block Copolymers ◽  
Anionic Polymerization ◽  
Diblock Copolymers ◽  
Living Anionic Polymerization ◽  
Molecular Weights

Living anionic polymerization of 4-diphenylphosphino styrene (DPPS) achieved well-defined homopolymers, poly(DPPS-b-S) styrenic block copolymers, and poly(I-b-DPPS) diene-based diblock copolymers with predictable molecular weights and narrow polydispersities.

Side Chain Liquid Crystalline Block Copolymers With Chiral Smectic C* Mesogens

1996 ◽  
Vol 425 ◽  
Author(s):  
Wen Yue Zheng ◽  
Paula T. Hammond
Keyword(s):  
Glass Transition ◽  
Block Copolymers ◽  
Anionic Polymerization ◽  
Liquid Crystalline ◽  
Diblock Copolymers ◽  
Side Chain ◽  
Synthesis And Characterization ◽  
Glass Transition Temperatures ◽  
Smectic C

AbstractA new series of side chain liquid crystalline-amorphous diblock copolymers has been successfully synthesized using chiral mesogens. Anionic polymerization techniques have been used to make these monodisperse diblock materials. Preliminary studies suggest that these microphase segregated diblock copolymers exhibit a smectic C* phase. This mesophase exists between and above the glass transition temperatures of the two polymer blocks. Synthesis and characterization of these novel materials are discussed.

Sign in / Sign up

Export Citation Format

Share Document