Tuning the synthesis of fully conjugated block copolymers to minimize architectural heterogeneity

2017 ◽  
Vol 5 (38) ◽  
pp. 20412-20421 ◽  
Author(s):  
Youngmin Lee ◽  
Melissa P. Aplan ◽  
Zach D. Seibers ◽  
S. Michael Kilbey ◽  
Qing Wang ◽  
...  
Keyword(s):  
Block Copolymers ◽  
Group Composition ◽  
Feed Ratio ◽  
End Group

Control of conversion, end group composition, and feed ratio is crucial to minimize homopolymer impurities in the synthesis of conjugated block copolymers for photovoltaics.

Double Thermoresponsive Block Copolymers Featuring a Biotin End Group

2010 ◽  
Vol 11 (9) ◽  
pp. 2432-2439 ◽  
Author(s):  
Florian D. Jochum ◽  
Peter J. Roth ◽  
Daniel Kessler ◽  
Patrick Theato
Keyword(s):  
Block Copolymers ◽  
End Group

RAFT Polymerization of Monomers with Highly Disparate Reactivities: Use of a Single RAFT Agent and the Synthesis of Poly(styrene-block-vinyl acetate)

2013 ◽  
Vol 66 (12) ◽  
pp. 1564 ◽  
Author(s):  
Lily A. Dayter ◽  
Kate A. Murphy ◽  
Devon A. Shipp
Keyword(s):  
Block Copolymers ◽  
Vinyl Acetate ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Good Control ◽  
Scanning Calorimetry ◽  
Styrene Polymerization ◽  
Reversible Addition ◽  
Raft Agent ◽  
End Group

A single reversible addition–fragmentation chain transfer (RAFT) agent, malonate N,N-diphenyldithiocarbamate (MDP-DTC) is shown to successfully mediate the polymerization of several monomers with greatly differing reactivities in radical/RAFT polymerizations, including both vinyl acetate and styrene. The chain transfer constants (Ctr) for MDP-DTC for both these monomers were evaluated; these were found to be ~2.7 in styrene and ~26 in vinyl acetate, indicating moderate control over styrene polymerization and good control of vinyl acetate polymerization. In particular, the MDP-DTC RAFT agent allowed for the synthesis of block copolymers of these two monomers without the need for protonation/deprotonation switching, as has been previously developed with N-(4-pyridinyl)-N-methyldithiocarbamate RAFT agents, or other end-group transformations. The thermal properties of the block copolymers were studied using differential scanning calorimetry, and those with sufficiently high molecular weight and styrene composition appear to undergo phase separation. Thus, MDP-DTC may be useful for the production of other block copolymers consisting of monomers with highly dissimilar reactivities.

Block copolymers and telechelic oligomers by end group reaction of polymethacrylates

1996 ◽  
Vol 102 (1) ◽  
pp. 91-98 ◽  
Author(s):  
Eberhard Esselbom ◽  
Jürgen Fock ◽  
Arno Knebelkamp
Keyword(s):  
Block Copolymers ◽  
Group Reaction ◽  
End Group

scholarly journals A systematic study of the effect of the hard end-group composition on the microphase separation, thermal and mechanical properties of supramolecular polyurethanes

Polymer ◽  
2016 ◽  
Vol 107 ◽  
pp. 368-378 ◽  
Author(s):  
Daniel Hermida Merino ◽  
Antonio Feula ◽  
Kelly Melia ◽  
Andrew T. Slark ◽  
Ioannis Giannakopoulos ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Systematic Study ◽  
Group Composition ◽  
Microphase Separation ◽  
Thermal And Mechanical Properties ◽  
End Group

scholarly journals Supramolecular Networks from Block Copolymers Based on Styrene and Isoprene Using Hydrogen Bonding Motifs—Part 1: Synthesis and Characterization

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1608 ◽  
Author(s):  
Elaine Rahmstorf ◽  
Volker Abetz
Keyword(s):  
Hydrogen Bonding ◽  
Block Copolymers ◽  
Ester Group ◽  
The Novel ◽  
Temperature Dependent ◽  
Scanning Calorimetry ◽  
Different Types ◽  
Supramolecular Networks ◽  
Subsequent Introduction ◽  
End Group

The combination of controlled anionic polymerization and subsequent introduction of hydrogen bonding groups was established to form thermo-reversible, supramolecular networks. Several polyisoprene-block-polystyrene-block-polyisoprene (ISI) copolymers—with polystyrene (PS) as the main block, and consequently giving the decisive material characteristics—were synthesized. The novel modification approach to post-functionalize the polyisoprene (PI) end-blocks and to introduce different motifs, which are able to form self-complementary hydrogen bonds, was attained. In the first step, hydroxylation was accomplished using 9-borabicyclo[3.3.1]nonane. Starting from the hydroxylated polymer, esterification with succinic anhydride was implemented to form an ester group with carboxylic end-group (-O-CO-CH2-CH2-COOH). In a second approach, 1,1’-carbonyldiimidazole was used as coupling agent to introduce various types of diamines (diethylenetriamine, triethylentetramine, and 2,6-diaminopyridine) to prepare urethane groups with amine end-group (-O-CO-NH-R-NH2). 1H NMR spectroscopy was used to confirm the successful synthesis and to calculate the degree of functionalization Df. Differential scanning calorimetry (DSC) showed a difference of the glass transition temperature Tg between unfunctionalized and functionalized block copolymers, but no greater influence between the different types of modification, and thus, on the Tg of the PS block. In temperature dependent FTIR spectroscopy, reversible processes were observed.

End group polarity and block symmetry effects on cloud point and hydrodynamic diameter of thermoresponsive block copolymers

2015 ◽  
Vol 53 (24) ◽  
pp. 2838-2848 ◽  
Author(s):  
Xu Xiang ◽  
Xiaochu Ding ◽  
Ning Chen ◽  
Beilu Zhang ◽  
Patricia A. Heiden
Keyword(s):  
Block Copolymers ◽  
Cloud Point ◽  
Hydrodynamic Diameter ◽  
End Group
Sign in / Sign up

Export Citation Format

Share Document