Analysis of the Competition between Cyclization and Linear Chain Growth in Kinetically Controlled A 2  + B 2 Step‐Growth Polymerizations Using Modeling Tools

2020 ◽  
Vol 29 (6) ◽  
pp. 2000050
Author(s):  
Juan Enrique Romero‐Hernández ◽  
Alfredo Cruz‐Rosado ◽  
Eduardo Vivaldo‐Lima ◽  
Joaquín Palacios‐Alquisira ◽  
Mikhail G. Zolotukhin
Keyword(s):  
Linear Chain ◽  
Chain Growth ◽  
Modeling Tools ◽  
Kinetically Controlled ◽  
Step Growth

Polymer Chemistry

2004 ◽  
Keyword(s):  
Conducting Polymers ◽  
Liquid Crystalline ◽  
Polymer Chemistry ◽  
Chain Growth ◽  
Crystalline Polymers ◽  
Wide Range ◽  
Cyclic Oligomers ◽  
Step Growth

Polymer Chemistry: A Practical Approach in Chemistry has been designed for both chemists working in and new to the area of polymer synthesis. It contains detailed instructions for preparation of a wide-range of polymers by a wide variety of different techniques, and describes how this synthetic methodology can be applied to the development of new materials. It includes details of well-established techniques, e.g. chain-growth or step-growth processes together with more up-to-date examples using methods such as atom-transfer radical polymerization. Less well-known procedures are also included, e.g. electrochemical synthesis of conducting polymers and the preparation of liquid crystalline elastomers with highly ordered structures. Other topics covered include general polymerization methodology, controlled/"living" polymerization methods, the formation of cyclic oligomers during step-growth polymerization, the synthesis of conducting polymers based on heterocyclic compounds, dendrimers, the preparation of imprinted polymers and liquid crystalline polymers. The main bulk of the text is preceded by an introductory chapter detailing some of the techniques available to the scientist for the characterization of polymers, both in terms of their chemical composition and in terms of their properties as materials. The book is intended not only for the specialist in polymer chemistry, but also for the organic chemist with little experience who requires a practical introduction to the field.

General procedures in chain-growth polymerization

2004 ◽  
Author(s):  
Najib Aragrag ◽  
Dario C. Castiglione
Keyword(s):  
Free Radical ◽  
Ring Opening ◽  
Point Of View ◽  
Polymerization Process ◽  
Undergraduate Teaching ◽  
Chain Growth ◽  
Reaction Conditions ◽  
Growth Processes ◽  
Reagent Purity ◽  
Step Growth

This chapter is intended to provide a general introduction to the laboratory techniques used in polymer synthesis, by focusing on some relatively well-known polymerizations that occur by chain-growth processes. In this way some of the more commonly used procedures in polymer chemistry are described. Due to the nature of the intermediates produced, such as free radicals, carbanions, carbocations, together with a range of organometallic species, the techniques often involve handling compounds in the complete absence of oxygen and moisture. Because of this the best results may require quite sophisticated equipment and glassware; however, it is our intention to show that the general procedures are accessible to any reasonably equipped laboratory, and indeed some of the techniques are suitable for use in an undergraduate teaching laboratory. Chain-growth polymerization involves the sequential step-wise addition of monomer to a growing chain. Usually, the monomer is unsaturated, almost always a derivative of ethene, and most commonly vinylic, that is, a monosubstituted ethane, 1 particularly where the growing chain is a free radical. For such monomers, the polymerization process is classified by the way in which polymerization is initiated and thus the nature of the propagating chain, namely anionic, cationic, or free radical; polymerization by coordination catalyst is generally considered separately as the nature of the growing chain-end may be less clear and coordination may bring about a substantial level of control not possible with other methods. Ring-opening polymerizations exhibit many of the features of chain-growth polymerization, but may also show some of the features expected from stepgrowth polymerizations. However, it is probably fair to say that from a practical point of view the techniques involved are rather similar or the same as those used in chain-growth processes and consequently some examples of ring-opening processes are provided here. It is particularly instructive to consider the requirements of chain-growth compared to step-growth processes in terms of the demands for reagent purity and reaction conditions.

The High Temperature Gel Permeation Chromatography Study on Poly (Phenylene Sulfide) Linear Chain Propagation

2010 ◽  
Vol 139-141 ◽  
pp. 661-665
Author(s):  
Yu Zhou ◽  
Bo Wen Cheng ◽  
Zhen Huan Li ◽  
De Xin Shen ◽  
Sheng Zhang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Temperature ◽  
Sodium Sulfide ◽  
Linear Chain ◽  
Gel Permeation Chromatography ◽  
Chain Propagation ◽  
Chain Growth ◽  
Gel Permeation ◽  
Methyl Pyrrolidone ◽  
Phenylene Sulfide

A linear and high molecular weight poly(phenylene sulfide) (PPS) was synthesized from P-dichlorobenzene (P-DCB) and anhydrous sodium sulfide in N-methyl pyrrolidone (NMP), and the High Temperature Gel Permeation Chromatography (HTGPC) technique was utilized to investigate the effects of reaction condition on PPS chain propagation. The experiment results indicated that the high pro-reaction temperature or high post-temperature would interfere with PPS chain propagation, and post-reaction time was another important factor to influence PPS molecular weight (Mw) extension. Furthermore, the optimized ratio of high Mw PPS polymer synthesis was typically at 3-6% molar excess of Na2S over p-dichlorobenzene, and N-methyl-2-pyrrolidone (NMP) were beneficial to the production of high Mw PPS due to the formation of sodium 4-(N-methylamino) butanoate (SMAB). The alkaline reagents such as Na3PO4 and K3PO4 et al could capture the H of -SH, which changed -SH into -SNa and promoted the chain growth of PPS to achieve extension.

Amphiphilic poly(disulfide) micelles and a remarkable impact of the core hydrophobicity on redox responsive disassembly

2015 ◽  
Vol 6 (36) ◽  
pp. 6465-6474 ◽  
Author(s):  
Dipankar Basak ◽  
Raju Bej ◽  
Suhrit Ghosh
Keyword(s):  
Triblock Copolymers ◽  
Triethylene Glycol ◽  
Monomethyl Ether ◽  
Chain Growth ◽  
Glycol Monomethyl Ether ◽  
The Core ◽  
Redox Responsive ◽  
Step Growth

Redox-responsive amphiphilic triblock copolymers based on poly(triethylene glycol monomethyl ether)methacrylate-b-poly(disulfide)-b-poly(triethylene glycol monomethyl ether)methacrylate (PTEGMA-b-PDS-b-PTEGMA) with different hydrophobicities of the PDS block were synthesized by step-growth followed by chain-growth polymerization.

Simultaneous step-growth and chain-growth cationic polymerization of styrenic monomers bearing carbazolyl groups

Polymer ◽  
2017 ◽  
Vol 129 ◽  
pp. 83-91 ◽  
Author(s):  
Irina V. Vasilenko ◽  
Aliaksei A. Vaitusionak ◽  
Jurgita Sutaite ◽  
Ausra Tomkeviciene ◽  
Jolita Ostrauskaite ◽  
...  
Keyword(s):  
Cationic Polymerization ◽  
Chain Growth ◽  
Step Growth

Brownian dynamics simulation of linear chain growth

2000 ◽  
Vol 98 (15) ◽  
pp. 1011-1023 ◽  
Author(s):  
M. C. Bujan-Nunez ◽  
B. Vazquez-Varela
Keyword(s):  
Brownian Dynamics ◽  
Linear Chain ◽  
Dynamics Simulation ◽  
Chain Growth ◽  
Brownian Dynamics Simulation
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