Next Article in Journal
Membrane Disintegration Caused by the Steroid Saponin Digitonin Is Related to the Presence of Cholesterol
Next Article in Special Issue
Microwave-Assisted Superheating and/or Microwave-Specific Superboiling (Nucleation-Limited Boiling) of Liquids Occurs under Certain Conditions but is Mitigated by Stirring
Previous Article in Journal
Design and Synthesis of New 2-Aryl-4,5-Dihydro-thiazole Analogues: In Vitro Antibacterial Activities and Preliminary Mechanism of Action
Previous Article in Special Issue
Synthetic Development of New 3-(4-Arylmethylamino)butyl-5-arylidene-rhodanines under Microwave Irradiation and Their Effects on Tumor Cell Lines and against Protein Kinases
Article Menu

Export Article

Open AccessArticle
Molecules 2015, 20(11), 20131-20145; doi:10.3390/molecules201119681

Molecular Differentiated Initiator Reactivity in the Synthesis of Poly(caprolactone)-Based Hydrophobic Homopolymer and Amphiphilic Core Corona Star Polymers

1
Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, Nottingham NG7 2RD, UK
2
School of Chemistry, University of Nottingham, Nottingham NG7 2RD, UK
3
Department of Chemical and Environmental Engineering, University of Nottingham Malaysia Campus, Jalan Broga, Semenyih 43500, Selangor Darul Ehsan, Malaysia
Current address: School of Biotechnology, International University, Vietnam National University, Ho Chi Minh City, Vietnam
*
Author to whom correspondence should be addressed.
Academic Editor: Marilena Radoiu
Received: 7 October 2015 / Revised: 26 October 2015 / Accepted: 27 October 2015 / Published: 9 November 2015
(This article belongs to the Special Issue Microwave-Assisted Organic Synthesis)
View Full-Text   |   Download PDF [3156 KB, uploaded 9 November 2015]   |  

Abstract

Macromolecules that possess three-dimensional, branched molecular structures are of great interest because they exhibit significantly differentiated application performance compared to conventional linear (straight chain) polymers. This paper reports the synthesis of 3- and 4-arm star branched polymers via ring opening polymerisation (ROP) utilising multi-functional hydroxyl initiators and Sn(Oct)2 as precatalyst. The structures produced include mono-functional hydrophobic and multi-functional amphiphilic core corona stars. The characteristics of the synthetic process were shown to be principally dependent upon the physical/dielectric properties of the initiators used. ROP’s using initiators that were more available to become directly involved with the Sn(Oct)2 in the “in-situ” formation of the true catalytic species were observed to require shorter reaction times. Use of microwave heating (MWH) in homopolymer star synthesis reduced reaction times compared to conventional heating (CH) equivalents, this was attributed to an increased rate of “in-situ” catalyst formation. However, in amphiphilic core corona star formation, the MWH polymerisations exhibited slower propagation rates than CH equivalents. This was attributed to macro-structuring within the reaction medium, which reduced the potential for reaction. It was concluded that CH experiments were less affected by this macro-structuring because it was disrupted by the thermal currents/gradients caused by the conductive/convective heating mechanisms. These gradients are much reduced/absent with MWH because it selectively heats specific species simultaneously throughout the entire volume of the reaction medium. These partitioning problems were overcome by introducing additional quantities of the species that had been determined to selectively heat. View Full-Text
Keywords: ring opening polymerisation; microwaves; star polymer; core corona star; dielectric properties ring opening polymerisation; microwaves; star polymer; core corona star; dielectric properties
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Supplementary material

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Deng, E.; Nguyen, N.T.; Hild, F.; Hamilton, I.E.; Dimitrakis, G.; Kingman, S.W.; Lau, P.-L.; Irvine, D.J. Molecular Differentiated Initiator Reactivity in the Synthesis of Poly(caprolactone)-Based Hydrophobic Homopolymer and Amphiphilic Core Corona Star Polymers. Molecules 2015, 20, 20131-20145.

Show more citation formats Show less citations formats

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]

Molecules EISSN 1420-3049 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top