DBU and TU Synergistically Induced Ring-Opening Polymerization of Phosphate Esters: A Mechanism Study

2021 ◽  
Author(s):  
Shuang Li ◽  
Han Lu ◽  
Xiaohui Kang ◽  
Pan Wang ◽  
Yi Luo
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Phosphate Esters ◽  
Phosphate Ester ◽  
Mechanism Study ◽  
Potential Applications

Biocompatible and biodegradable polyphosphoesters derived from ring-opening polymerization (ROP) of phosphate ester have drawn increasing attention because of their potential applications in clinical and therapeutic fields. The related knowledge of...

Poly(ω-pentadecalactone)-b-poly(l-lactide) Block Copolymers via Organic-Catalyzed Ring Opening Polymerization and Potential Applications

2015 ◽  
Vol 4 (4) ◽  
pp. 408-411 ◽  
Author(s):  
Richard Todd ◽  
Sarah Tempelaar ◽  
Giada Lo Re ◽  
Stephen Spinella ◽  
Scott A. McCallum ◽  
...  
Keyword(s):  
Block Copolymers ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Potential Applications

Properties of polylactide, obtained from lactic acid in the process of lactic fermentation of lactose in whey post production (waste)

2018 ◽  
Vol 2 (90) ◽  
pp. 58-68
Author(s):  
S. Maślanka ◽  
J. Juszczyński ◽  
T. Kraszewski ◽  
W. Oleksy
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Ring Opening ◽  
Fermentation Process ◽  
Ring Opening Polymerization ◽  
Decomposition Temperature ◽  
Raw Material ◽  
Thermal Methods ◽  
Lactic Fermentation ◽  
Potential Applications

Purpose: This publication provides a description of RDC Glokor’s own research into the effectiveness of the lactic fermentation process of lactose, lactic acid concentration and polylactide (PLA) production by ring-opening polymerization obtained from the condensation of two molecules of lactic acid. Furthermore, this publication sets out to determine potential applications of the PLA as a commercial material with a selection of thermal properties. Design/methodology/approach: In the described research works, a lactic fermentation process was used in which lactose is converted to lactic acid with the participation of Lactic Acid Bacteria. Polylactide was obtained indirectly by Ring Opening Polymerization and by direct polymerization, straight from lactic acid, omitting the intermediate stages. Next, the obtained lactide and polylactide were examined by spectroscopic methods (IR, NMR) to determine their purity. Thermal methods (TG, DSC) to determine thermoplastic properties, i.e. softening point, decomposition temperature and glass transition temperature. Findings: Obtained from waste whey, PLA and its copolymers are excellent biodegradable polymers that have the potential to be used in medicine as resorbable surgical strands, biopolymers for implant production, as well as in many industries including for the production of biodegradable bottles and disposable packaging, 3D printer cartridges. Research limitations/implications: The research on lactic acid and lactide polymerization described in this article is still a new issue that requires further research to optimize PLA processes with industry-specific thermoplastic and physicochemical properties. Originality/value: In the basic waste processing of milk, there is a large volume of whey sour, which is ecologically dangerous for waste treating. Due to the high content of lactose (up to 6%) this waste can be used as a raw material in the lactic fermentation process in which lactose is converted to lactic acid with the participation of lactic acid bacteria. Lactic acid can be concentrated and subjected to a dehydration process to lactide, which in the final stage is subjected to the process of ring-opening polymerization in order to produce biodegradable polylactide. The described process of carrying out the lactose contained in PLA whey is an innovative way to obtain a biodegradable usable polymer, which can be used to replace plastics such as polypropylene and polyethylene.

scholarly journals Effect on electrospun fibres by synthesis of high branching polylactic acid

2018 ◽  
Vol 5 (9) ◽  
pp. 180134 ◽  
Author(s):  
Wen Shen ◽  
Guanghua Zhang ◽  
Xuemei Ge ◽  
Yali Li ◽  
Guodong Fan
Keyword(s):  
Tissue Engineering ◽  
Molecular Weight ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Tissue Engineering Scaffolds ◽  
Polar Property ◽  
Strong Adsorption ◽  
Potential Applications ◽  
Ultra High Molecular Weight ◽  
Fibre Preparation

Polylactic electrospun porous fibres have been widely used in tissue engineering scaffolds. However, the application of linear polylactic is limited due to its poor hydrophilicity, which leads to phase separation and has been seldom used in porous fibre preparation. Instead, branching polylactic acts as a new effective method to prepare porous fibres because it can increase polylactic polar property and make it easy to be formulated in the following application. In the current study, we prepared an ultra-high molecular weight of high branching polylactic with glycerol as the initiator by controlling the ring-opening polymerization time, adding amount of catalyst and glycerol. The structure, molecular weight and thermal properties of copolymers were tested subsequently. The result showed that the surface of the high branching polylactic films is smooth, hydrophilic and porous. This branching polylactic formed electrospun porous fibres and possessed a strong adsorption of silver ion. Our study provided a simple and efficient way to synthesize branching polylactic polymer and prepare electrospun porous fibres, which may provide potential applications in the field of biomaterials for tissue engineering or antibacterial dressing compared with the application of linear polylactic and 3-arm polylactic materials.

Structures and potential applications of multihydroxyl branched polyethers obtained by cationic ring-opening polymerization involving activated monomer mechanism

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Melania Bednarek
Keyword(s):  
Ring Opening ◽  
Star Polymers ◽  
Ring Opening Polymerization ◽  
Cyclic Ethers ◽  
Low Molecular Weight ◽  
Hydroxyl Groups ◽  
Potential Applications ◽  
Cationic Ring Opening Polymerization ◽  
Highly Strained ◽  
Thermodynamic Restrictions

AbstractThe synthesis and potential applications of functional, branched polyethers prepared by cationic ring-opening polymerization is reviewed, mainly on the base of the work from the author’s laboratory. Polymerization of cyclic monomers of ABx type, including highly strained 3- and 4-membered as well as weakly strained 5-membered cyclic ethers substituted with hydroxyl groups is discussed. Cationic polymerization of such monomers proceeds with participation of activated monomer mechanism which leads to the formation of branches. Hydroxy-substituted 4-membered cyclic ethers are highly strained; thus there are no thermodynamic restrictions for their polymerization, but these monomers are not easily available. Thus the possibility of using easily accessible 5-membered hydroxy-substituted cyclic ethers as monomers for cationic ring-opening polymerization was explored in spite of expected thermodynamic limitations due to low ring strain of those monomers. It was found that 5-membered hydroxysubstituted cyclic ethers undergo polymerization; however only low molecular weight products may be obtained from these monomers. It is shown in this review that such products may be useful and some examples of their applications in further synthesis e.g. in the preparation of star polymers and as surface modifying agents in the synthesis of organic/inorganic hybrid materials are described.

Controlled ring-opening polymerization of lactide by group 3 metal complexes

2007 ◽  
Vol 79 (11) ◽  
pp. 2013-2030 ◽  
Author(s):  
Abderramane Amgoune ◽  
Christophe M. Thomas ◽  
Jean-François Carpentier
Keyword(s):  
Lactic Acid ◽  
Metal Complexes ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Agricultural Fields ◽  
Research Results ◽  
Potential Applications ◽  
Group 3 ◽  
Biodegradable Properties

In this review, attention is focused on the use of group 3 metal complexes for the ring-opening polymerization (ROP) of lactide to give polylactides (PLAs). Synthesis of PLAs has been studied intensively due to their biocompatible and biodegradable properties and their potential applications in medical and agricultural fields. ROP of lactide, a cyclic diester of lactic acid, provides PLA. This review includes our recent research results and implications in developing new amino-bis(phenolate) group 3 initiators for the synthesis of polyesters.

Substituent Effects on the Thermal Decomposition of Phosphate Esters on Ferrous Surfaces

2019 ◽  
Author(s):  
James Ewen ◽  
Carlos Ayestaran Latorre ◽  
Arash Khajeh ◽  
Joshua Moore ◽  
Joseph Remias ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Film Formation ◽  
Substituent Effects ◽  
Vapour Phase ◽  
Industrial Applications ◽  
Phosphate Esters ◽  
Antiwear Additives ◽  
Formation Mechanisms ◽  
Phosphate Ester ◽  
Wide Range

<p>Phosphate esters have a wide range of industrial applications, for example in tribology where they are used as vapour phase lubricants and antiwear additives. To rationally design phosphate esters with improved tribological performance, an atomic-level understanding of their film formation mechanisms is required. One important aspect is the thermal decomposition of phosphate esters on steel surfaces, since this initiates film formation. In this study, ReaxFF molecular dynamics simulations are used to study the thermal decomposition of phosphate esters with different substituents on several ferrous surfaces. On Fe<sub>3</sub>O<sub>4</sub>(001) and α-Fe(110), chemisorption interactions between the phosphate esters and the surfaces occur even at room temperature, and the number of molecule-surface bonds increases as the temperature is increased from 300 to 1000 K. Conversely, on hydroxylated, amorphous Fe<sub>3</sub>O<sub>4</sub>, most of the molecules are physisorbed, even at high temperature. Thermal decomposition rates were much higher on Fe<sub>3</sub>O<sub>4</sub>(001) and particularly α-Fe(110) compared to hydroxylated, amorphous Fe<sub>3</sub>O<sub>4</sub>. This suggests that water passivates ferrous surfaces and inhibits phosphate ester chemisorption, decomposition, and ultimately film formation. On Fe<sub>3</sub>O<sub>4</sub>(001), thermal decomposition proceeds mainly through C-O cleavage (to form surface alkyl and aryl groups) and C-H cleavage (to form surface hydroxyls). The onset temperature for C-O cleavage on Fe<sub>3</sub>O<sub>4</sub>(001) increases in the order: tertiary alkyl < secondary alkyl < primary linear alkyl ≈ primary branched alkyl < aryl. This order is in agreement with experimental observations for the thermal stability of antiwear additives with similar substituents. The results highlight surface and substituent effects on the thermal decomposition of phosphate esters which should be helpful for the design of new molecules with improved performance.</p>

A Recommender System for Inverse Design of Polycarbonates and Polyesters

2020 ◽  
Author(s):  
Nathaniel Park ◽  
Dmitry Yu. Zubarev ◽  
James L. Hedrick ◽  
Vivien Kiyek ◽  
Christiaan Corbet ◽  
...  
Keyword(s):  
Ring Opening ◽  
High Performance ◽  
Recommendation System ◽  
Polymeric Materials ◽  
Monomer Conversion ◽  
Design Strategy ◽  
Ring Opening Polymerization ◽  
Inverse Design ◽  
False Negatives ◽  
Accelerate Development

The convergence of artificial intelligence and machine learning with material science holds significant promise to rapidly accelerate development timelines of new high-performance polymeric materials. Within this context, we report an inverse design strategy for polycarbonate and polyester discovery based on a recommendation system that proposes polymerization experiments that are likely to produce materials with targeted properties. Following recommendations of the system driven by the historical ring-opening polymerization results, we carried out experiments targeting specific ranges of monomer conversion and dispersity of the polymers obtained from cyclic lactones and carbonates. The results of the experiments were in close agreement with the recommendation targets with few false negatives or positives obtained for each class.<br>

Bisurea and Bisthiourea H-Bonding Organocatalysts for Ring-Opening Polymerization: Cues for the Catalyst Design

2019 ◽  
Vol 52 (23) ◽  
pp. 9232-9237 ◽  
Author(s):  
Rukshika S. Hewawasam ◽  
U. L. D. Inush Kalana ◽  
Nayanthara U. Dharmaratne ◽  
Thomas J. Wright ◽  
Timothy J. Bannin ◽  
...  
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Catalyst Design
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