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Polymers
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Polymerization Kinetics
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Polymerization Kinetics

A special issue of Polymers (ISSN 2073-4360).

Deadline for manuscript submissions: closed (20 May 2018) | Viewed by 37552

Special Issue Editor

Dr. Simon Harrisson

E-Mail Website
Guest Editor
Laboratoire des IMRCP, Université de Toulouse, CNRS UMR 5623, Université Paul Sabatier, 31062 Toulouse, France
Interests: polymerization kinetics and mechanisms; self assembly of block and gradient copolymers

Special Issue Information

Dear Colleagues,

The study of polymerization kinetics is fundamental to the production of polymers. While thermodynamic considerations determine whether or not a given monomer will polymerize, the properties of the resulting polymer depend on kinetic parameters. These properties include the chain length distribution, tacticity, and composition (in the case of copolymers). The last 25 years have seen a revitalization of polymer chemistry, with the development of many new polymerization techniques. Most recently, the concept of precision polymer synthesis has emerged, which seeks to control all aspects of polymer structure. Accompanying these developments has been a resurgence of interest in polymerization kinetics. The interplay of synthesis and kinetic analysis has allowed the development of new structures and architectures which were previously impossible. This Special Issue of Polymers is dedicated to current efforts in the study of polymerization kinetics. Of particular interest are the application of kinetic studies to precision polymerization, and the use of insights derived from polymerization kinetics to the synthesis of new polymers and copolymers.

Dr. Simon Harrisson
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 submissions that pass pre-check are 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. Polymers 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 2700 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

  • Precision polymerization
  • Reversible Deactivation Radical Polymerization
  • Living/controlled polymerization
  • Step polymerization
  • Copolymerization
  • Branching

Published Papers (7 papers)

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Research

9 pages, 920 KiB  
Article
The Chain Length Distribution of an Ideal Reversible Deactivation Radical Polymerization
by Simon Harrisson
Polymers 2018, 10(8), 887; https://doi.org/10.3390/polym10080887 - 08 Aug 2018
Cited by 14 | Viewed by 5869
Abstract
The chain length distribution (CLD) of a reversible deactivation radical polymerization at full conversion is shown to be a negative binomial distribution with parameters that are simple functions of the number-average degree of polymerization and either the chain transfer constant (in the case [...] Read more.
The chain length distribution (CLD) of a reversible deactivation radical polymerization at full conversion is shown to be a negative binomial distribution with parameters that are simple functions of the number-average degree of polymerization and either the chain transfer constant (in the case of polymerizations that incorporate a reversible chain transfer step) or the concentrations of dormant polymer chains and deactivating agent and the rate constants of propagation and deactivation (other types of RDRP). Expressions for the CLD at intermediate conversions are also derived, and shown to be consistent with known expressions for the number-average degree of polymerization and dispersity. It is further demonstrated that these CLDs are well-approximated by negative binomial distributions with appropriate choice of parameters. The negative binomial distribution is thus a useful model for CLDs of reversible deactivation radical polymerizations. Full article
(This article belongs to the Special Issue Polymerization Kinetics)
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16 pages, 2235 KiB  
Article
Mid-Chain Radical Migration in the Radical Polymerization of n-Butyl Acrylate
by Nicholas Ballard, Antonio Veloso and José M. Asua
Polymers 2018, 10(7), 765; https://doi.org/10.3390/polym10070765 - 12 Jul 2018
Cited by 17 | Viewed by 4389
Abstract
The occurrence of intramolecular transfer to polymer in the radical polymerization of acrylic monomers has been extensively documented in the literature. Whilst it has been largely assumed that intramolecular transfer to polymer leads to short chain branches, there has been some speculation over [...] Read more.
The occurrence of intramolecular transfer to polymer in the radical polymerization of acrylic monomers has been extensively documented in the literature. Whilst it has been largely assumed that intramolecular transfer to polymer leads to short chain branches, there has been some speculation over whether the mid-chain radical can migrate. Herein, by the matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry (MS) of poly(n-butyl acrylate) synthesized by solution polymerization under a range of conditions, it is shown that this mid-chain radical migration does occur in the radical polymerization of acrylates conducted at high temperatures, as is evident from the shape of the molecular weight distribution. Using a mathematical model, an initial approximation of the rate at which migration occurs is made and the distribution of branching lengths formed in this scenario is explored. It is shown that the polymerizations carried out under a low monomer concentration and at high temperatures are particularly prone to radical migration reactions, which may affect the rheological properties of the polymer. Full article
(This article belongs to the Special Issue Polymerization Kinetics)
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14 pages, 2133 KiB  
Article
Investigating the Mechanism of Horseradish Peroxidase as a RAFT-Initiase
by Alex P. Danielson, Dylan Bailey Van-Kuren, Joshua P. Bornstein, Caleb T. Kozuszek, Jason A. Berberich, Richard C. Page and Dominik Konkolewicz
Polymers 2018, 10(7), 741; https://doi.org/10.3390/polym10070741 - 05 Jul 2018
Cited by 20 | Viewed by 6185
Abstract
A detailed mechanistic and kinetic study of enzymatically initiated RAFT polymerization is performed by combining enzymatic assays and polymerization kinetics analysis. Horseradish peroxidase (HRP) initiated RAFT polymerization of dimethylacrylamide (DMAm) was studied. This polymerization was controlled by 2-(propionic acid)ylethyl trithiocarbonate (PAETC) in the [...] Read more.
A detailed mechanistic and kinetic study of enzymatically initiated RAFT polymerization is performed by combining enzymatic assays and polymerization kinetics analysis. Horseradish peroxidase (HRP) initiated RAFT polymerization of dimethylacrylamide (DMAm) was studied. This polymerization was controlled by 2-(propionic acid)ylethyl trithiocarbonate (PAETC) in the presence of H2O2 as a substrate and acetylacetone (ACAC) as a mediator. In general, well controlled polymers with narrow molecular weight distributions and good agreement between theoretical and measured molecular weights are consistently obtained by this method. Kinetic and enzymatic assay analyses show that HRP loading accelerates the reaction, with a critical concentration of ACAC needed to effectively generate polymerization initiating radicals. The PAETC RAFT agent is required to control the reaction, although the RAFT agent also has an inhibitory effect on enzymatic performance and polymerization. Interestingly, although H2O2 is the substrate for HRP there is an optimal concentration near 1 mM, under the conditions studies, with higher or lower concentrations leading to lower polymerization rates and poorer enzymatic activity. This is explained through a competition between the H2O2 acting as a substrate, but also an inhibitor of HRP at high concentrations. Full article
(This article belongs to the Special Issue Polymerization Kinetics)
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15 pages, 7507 KiB  
Article
Kinetic Prediction of Fast Curing Polyurethane Resins by Model-Free Isoconversional Methods
by Michael Stanko and Markus Stommel
Polymers 2018, 10(7), 698; https://doi.org/10.3390/polym10070698 - 23 Jun 2018
Cited by 44 | Viewed by 6983
Abstract
In this work, the characterisation of reaction kinetics of a methylene diphenyl diisocyanate (MDI)-based fast curing polyurethane resin (PUR) and the mathematical description of its curing process are presented. For the modelling of the reaction process isoconversional methods, which are also called model-free [...] Read more.
In this work, the characterisation of reaction kinetics of a methylene diphenyl diisocyanate (MDI)-based fast curing polyurethane resin (PUR) and the mathematical description of its curing process are presented. For the modelling of the reaction process isoconversional methods, which are also called model-free approaches, are used instead of model-based approaches. One of the main challenges is the characterisation of a reactive system with a short pot life, which already starts to crosslink below room temperature. The main focus is the evaluation of the applicability of isoconversional methods for predicting the reaction kinetics of fast curing polyurethane resins. In order to realise this, a repeatable methodology for the determination of time- and temperature-dependent reaction curves using differential scanning calorimetry (DSC) is defined. The cure models defined by this method serve as the basis for process simulations of PUR processing technologies such as resin transfer moulding (RTM) or reactive injection moulding (RIM) and reactive extrusion (REX). The characterisation of the reaction kinetics using DSC measurements is carried out under isothermal and non-isothermal conditions. Within this work isoconversional methods have been applied successfully to experimentally determined DSC data sets. It is shown that the reaction kinetics of fast curing polyurethane resins can be predicted using this methods. Furthermore, it is demonstrated that the time-dependent change of conversion of the considered polyurethane under isothermal curing conditions can also be predicted using isoconversional methods based on non-isothermal DSC measurements. This results in a significant reduction in the experimental effort required to characterise and model the curing process of polyurethanes. Full article
(This article belongs to the Special Issue Polymerization Kinetics)
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9 pages, 1488 KiB  
Communication
Size-Controllable Enzymatic Synthesis of Short Hairpin RNA Nanoparticles by Controlling the Rate of RNA Polymerization
by Hyejin Kim, Dajeong Kim, Jaepil Jeong, Hyunsu Jeon and Jong Bum Lee
Polymers 2018, 10(6), 589; https://doi.org/10.3390/polym10060589 - 28 May 2018
Cited by 8 | Viewed by 4439
Abstract
Thanks to a wide range of biological functions of RNA, and advancements in nanotechnology, RNA nanotechnology has developed in multiple ways for RNA-based therapeutics. In particular, among RNA engineering techniques, enzymatic self-assembly of RNA structures has gained great attention for its high packing [...] Read more.
Thanks to a wide range of biological functions of RNA, and advancements in nanotechnology, RNA nanotechnology has developed in multiple ways for RNA-based therapeutics. In particular, among RNA engineering techniques, enzymatic self-assembly of RNA structures has gained great attention for its high packing density of RNA, with a low cost and one-pot synthetic process. However, manipulation of the overall size of particles, especially a reduction in size, has not been studied in depth. Here, we reported the enzymatic self-assembly of short hairpin RNA particles for the downregulation of target genes, and a rational approach to the manipulation of the resultant particle size. This is the first report of the size-controllable enzymatic self-assembly of short hairpin RNA nanoparticles. While keeping all the benefits of an enzymatic approach, the overall size of the RNA particles was controlled on a scale of 2 μm to 100 nm, falling within the therapeutically applicable size range. Full article
(This article belongs to the Special Issue Polymerization Kinetics)
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10 pages, 3107 KiB  
Article
A Highly Efficient Aromatic Amine Ligand/Copper(I) Chloride Catalyst System for the Synthesis of Poly(2,6-dimethyl-1,4-phenylene ether)
by Kisoo Kim, Min Jae Shin, Yong Tae Kim, Joong-In Kim and Young Jun Kim
Polymers 2018, 10(4), 350; https://doi.org/10.3390/polym10040350 - 22 Mar 2018
Cited by 2 | Viewed by 4489
Abstract
Highly active catalyst systems for polymerizing 2,6-dimethylphenol were studied by using aromatic amine ligands and copper(I) chloride. The aromatic amine ligands employed were pyridine, 1-methylimidazole, 2-aminopyridine, 3-aminopyridine, and 4-aminopyridine. A mixture of chloroform and methanol (9:1, v/v) was used as [...] Read more.
Highly active catalyst systems for polymerizing 2,6-dimethylphenol were studied by using aromatic amine ligands and copper(I) chloride. The aromatic amine ligands employed were pyridine, 1-methylimidazole, 2-aminopyridine, 3-aminopyridine, and 4-aminopyridine. A mixture of chloroform and methanol (9:1, v/v) was used as a polymerization solvent. All experiments were performed with oxygen uptake measurement apparatus, while the reaction rate for each aromatic amine ligand-Cu catalyst system and the amount of by-product, 3,3′,5,5′-Tetramethyl-4,4′diphenoquinone (DPQ), were measured to determine the efficiency of the catalyst systems. The 4-aminopyridine/Cu (I) catalyst system was found to be extremely efficient in poly(2,6-dimethyl-1,4-phenylene ether) (PPE) synthesis; it had the fastest reaction rate of 6.98 × 10−4 mol/L·s and the lowest DPQ production. The relatively high basicity of 4-aminopyridne and the less steric hindrance arising from a coordination of Cu and 4-aminopyridine in this catalyst are responsible for the fast polymerization rate. When 2-aminoprydine (an isomer of 4-aminopyridine) was used as a ligand, however, no polymerization occurred probably due to steric hindrance. Full article
(This article belongs to the Special Issue Polymerization Kinetics)
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23 pages, 3900 KiB  
Article
Effect of the Configuration of a Bulky Aluminum Initiator on the Structure of Copolymers of l,l-Lactide with Symmetric Comonomer Trimethylene Carbonate
by Marta Socka, Ryszard Szymanski, Stanislaw Sosnowski and Andrzej Duda
Polymers 2018, 10(1), 70; https://doi.org/10.3390/polym10010070 - 13 Jan 2018
Cited by 2 | Viewed by 3817
Abstract
The effect of configuration of an asymmetric bulky initiator 2,2′-[1,1′-binaphtyl-2,2′-diyl- bis-(nitrylomethilidyne)]diphenoxy aluminum isopropoxide (Ini) on structure of copolymer of asymmetric monomer l,l-lactide (Lac) with symmetric comonomer trimethylene carbonate (Tmc) was studied using polarimetry, dilatometry, [...] Read more.
The effect of configuration of an asymmetric bulky initiator 2,2′-[1,1′-binaphtyl-2,2′-diyl- bis-(nitrylomethilidyne)]diphenoxy aluminum isopropoxide (Ini) on structure of copolymer of asymmetric monomer l,l-lactide (Lac) with symmetric comonomer trimethylene carbonate (Tmc) was studied using polarimetry, dilatometry, Size Exclusion Chromatography (SEC), and Carbon Nuclear Magnetic Resonance (13C NMR). When the S-enantiomer of Ini was used the distribution in copolymer chains at the beginning of polymerization is statistical, with alternacy tendency, changing next through a gradient region to homoblocks of Tmc. However, when R-Ini was used, the product formed was a gradient oligoblock one, with Tmc blocks prevailing at the beginning, changing to Lac blocks dominating at the end part of chains. Initiation of copolymerization with the mixture of both initiator enantiomers (S:R = 6:94) gave a multiblock copolymer of similar features but shorter blocks. Analysis of copolymerization progress required complex analysis of dilatometric data, assuming different molar volume contraction coefficients for units located in different triads. Comonomer reactivity ratios of studied copolymerizations were determined. Full article
(This article belongs to the Special Issue Polymerization Kinetics)
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