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Special Issue "Polymer Entanglement"

A special issue of Molecules (ISSN 1420-3049).

Deadline for manuscript submissions: 30 September 2020.

Special Issue Editor

Dr. Sara Ronca
Website
Guest Editor
Department of Materials, Loughborough University, Leicestershire, LE11 3TU, United Kingdom
Interests: polymer; catalysis; polyolefins; organometallic chemistry
Special Issues and Collections in MDPI journals

Special Issue Information

Dear Colleagues,

Polymeric materials, either synthetic or natural, are nowadays ubiquitous in our daily life thanks to the large variety of properties that can be realised by modification of their structure, architecture, and assembly. Since the pioneering work of Pierre de Gennes, Sam Edwards, and Masao Doi, we know that the thermal motion of polymers, either in bulk or in concentrated solutions, is governed by the topological restriction induced by neighbouring chains, i.e., by the presence of entanglements.

The presence (or even absence!) of entanglements between macromolecules will affect chain dynamics in melt and/or solution, thus influencing the response of the material during processing, the formation and stability of micelles, and the elasticity of polymeric gels. Understanding how entanglements form with respect to the polymer’s microstructure/architecture, and how they evolve as a function of thermal or mechanical stresses, is then pivotal for the design of new and improved materials.

The present Special Issue will showcase a selection of articles reporting on recent developments in, and the current standing of, the topic of polymer entanglements, covering both experimental research and theoretical modelling aspects.

Dr. Sara Ronca
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Molecules is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2000 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • polymer
  • reptation
  • entanglements
  • chain dynamic
  • rheology

Published Papers

This special issue is now open for submission, see below for planned papers.

Planned Papers

The below list represents only planned manuscripts. Some of these manuscripts have not been received by the Editorial Office yet. Papers submitted to MDPI journals are subject to peer-review.

Type of paper: Article
Tentative title: Role of Entanglements on the Performance of Branched Polymers as Aqueous Adhesives in Binder Jetting Additive Manufacturing of Pharmaceuticals
Authors: Emily Wilts, Da Ma, Christopher Williams, and Timothy Long
Affiliations: Department of Chemistry, Macromolecules Innovation Institute, Virginia Tech, Blacksburg, VA 2406, Department of Mechanical Engineering, Macromolecules Innovation Institute, Virginia Tech, Blacksburg, VA 24061
Abstract: Personalized dosage pharmaceuticals provide patients with exact dosing based on metabolic and genomic screenings with the avoidance of multi-drug interactions and incorrect dosing. Additive manufacturing facilitates the production of oral tablets and implantable devices capable of personalized dosage through its inherently tunable process. Binder jetting provides an advantageous method of creating oral tablets because of the ability to deliver very small doses, usage of common excipients in the pharmaceutical industry, and the versatility of a multi-material system. Polymers as adhesives for binders sustain limitations, where the viscosity constraints of binder jetting limit the molecular weight and polymer concentration in the binder. To ameliorate this problem, this manuscript describes designed graft copolymers with low or nonexistent entanglements as polymeric binders, which provided decreased solution viscosity at higher concentrations compared to linear polymers at the same molecular weight. Higher concentrations of polymer fill in interstitial voids and increases the strength of binder jetted parts. Previously, 4-arm star poly(vinyl pyrrolidone) (PVP) demonstrated an increase in compressive strength compared to linear analogs at the same molecular weight. This manuscript aims to use graft PVP (PMeOx-g-PVP), strategically designed to obtain an even lower solution viscosity compared to previous examples. In this study, PMeOx-g-PVP in DI water printed at a higher wt%, 14 wt%, compared to linear and 4-arm star analogs, which produced the strongest tablet of the architecture series, 1.6 MPa. Increased critical overlap concentrations (C*) enabled solutions of PMeOx-g-PVP to print at a higher wt% compared to linear and 4-arm star analogs, which also predicted the maximum jettable wt% in these systems printed on a thermal printhead.
Submission Date: March 15th to 31st
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