scholarly journals A machine-readable online database for rate coefficients in radical polymerization

2021 ◽  
Author(s):  
Joren Van Herck ◽  
Simon Harrisson ◽  
Robin Hutchinson ◽  
Gregory Thomas Russell ◽  
Tanja Junkers
Keyword(s):  
Radical Polymerization ◽  
Kinetic Data ◽  
Access Point ◽  
Rate Coefficients ◽  
Online Database ◽  
Central Access ◽  
Radical Polymerizations ◽  
Machine Readable

An online database created and curated by an IUPAC subcommittee is introduced. It is designed to act as central access point for finding reliable kinetic data on radical polymerizations. The...

Modeling of Free Radical Polymerization of Azobenzene-based Linear Polymers

2012 ◽  
Vol 1403 ◽  
Author(s):  
Danish Iqbal ◽  
C. Melchert ◽  
M. Behl ◽  
A. Lendlein ◽  
S. Beuermann
Keyword(s):  
Free Radical ◽  
Radical Polymerization ◽  
Butyl Acrylate ◽  
Software Package ◽  
Kinetic Data ◽  
Liquid Crystalline ◽  
Linear Polymers ◽  
Reasonable Approximation ◽  
Radical Polymerizations ◽  
Remarkable Agreement

ABSTRACTModeling of free radical polymerizations of the liquid-crystalline monomer 6-[4-(4-heptyloxyphenylazo)phenoxy]hexylacrylate using the PREDICI software package is reported. The model accounts for all elemental reactions that were identified to be important for radical polymerizations of acrylate-type monomers. On the basis of butyl acrylate kinetic data a remarkable agreement between number average molar masses from modelling (Mn,sim) and from experiments (Mn,exp) is observed: Mn,sim = 17800 g·mol−1 and Mn,exp = 17400 g·mol−1. Similarly, dispersity values of 1.8 and 1.6 were determined via modelling and experiments, respectively. It is shown that the assumption of butyl acrylate kinetics provides a reasonable approximation even for acrylate-based monomers having mesogenic substituents.

Chain-Length-Dependent Termination in Acrylate Radical Polymerization Studied via Pulsed-Laser-Initiated RAFT Polymerization

2007 ◽  
Vol 60 (10) ◽  
pp. 779 ◽  
Author(s):  
Michael Buback ◽  
Pascal Hesse ◽  
Thomas Junkers ◽  
Thomas Theis ◽  
Philipp Vana
Keyword(s):  
Radical Polymerization ◽  
Chain Length ◽  
Near Infrared ◽  
Pulsed Laser ◽  
Monomer Concentration ◽  
Nir Spectroscopy ◽  
Single Pulse ◽  
Rate Coefficients ◽  
Radical Chain ◽  
Chain Flexibility

The chain-length dependence of the termination rate coefficient, kt, in methyl acrylate (MA) and dodecyl acrylate (DA) radical polymerization has been determined via the single pulse pulsed-laser polymerization near-infrared reversible addition–fragmentation chain transfer (SP-PLP-NIR-RAFT) technique. Polymerization is induced by a laser SP and the resulting decay in monomer concentration, cM, is monitored via NIR spectroscopy with a time resolution of microseconds. A RAFT agent ensures the correlation of radical chain length and monomer-to-polymer conversion. The obtained rate coefficients for termination of two radicals of approximately the same chain length, i, are represented by power-law expressions, kt(i,i) ∝ i–α. For both monomers, composite model behaviour of kt(i,i) showing two distinct chain length regimes is observed. The exponent αs referring to short chain lengths is close to unity, whereas the exponent αl, which characterizes the chain-length dependency of large radicals, is slightly above the theoretical value for coiled chain-end radicals. The crossover chain length, ic, which separates the two regions, decreases from MA (ic = 30) to DA (ic = 20). The results for MA and DA are consistent with earlier data reported for butyl acrylate. There appears to be a correlation of αs and ic with chain flexibility.

scholarly journals COVID-19 preVIEW: Semantic Search to Explore COVID-19 Research Preprints

2021 ◽  
Author(s):  
Lisa Langnickel ◽  
Roman Baum ◽  
Johannes Darms ◽  
Sumit Madan ◽  
Juliane Fluck
Keyword(s):  
Search Engine ◽  
Access Point ◽  
Semantic Search ◽  
Web Interface ◽  
Disease Trajectory ◽  
Human Genes ◽  
Central Access ◽  
Semantic Information Retrieval ◽  
User Friendly ◽  
Semantic Search Engine

During the current COVID-19 pandemic, the rapid availability of profound information is crucial in order to derive information about diagnosis, disease trajectory, treatment or to adapt the rules of conduct in public. The increased importance of preprints for COVID-19 research initiated the design of the preprint search engine preVIEW. Conceptually, it is a lightweight semantic search engine focusing on easy inclusion of specialized COVID-19 textual collections and provides a user friendly web interface for semantic information retrieval. In order to support semantic search functionality, we integrated a text mining workflow for indexing with relevant terminologies. Currently, diseases, human genes and SARS-CoV-2 proteins are annotated, and more will be added in future. The system integrates collections from several different preprint servers that are used in the biomedical domain to publish non-peer-reviewed work, thereby enabling one central access point for the users. In addition, our service offers facet searching, export functionality and an API access. COVID-19 preVIEW is publicly available at https://preview.zbmed.de.

scholarly journals Specifications of Standards in Systems and Synthetic Biology

2015 ◽  
Vol 12 (2) ◽  
pp. 1-3 ◽  
Author(s):  
Falk Schreiber ◽  
Gary D. Bader ◽  
Martin Golebiewski ◽  
Michael Hucka ◽  
Benjamin Kormeier ◽  
...  
Keyword(s):  
Synthetic Biology ◽  
Information Exchange ◽  
Computational Models ◽  
Access Point ◽  
Economic Benefits ◽  
Special Issue ◽  
Community Initiative ◽  
Central Access ◽  
Oral Presentations ◽  
Modeling In Biology

Summary Standards shape our everyday life. From nuts and bolts to electronic devices and technological processes, standardised products and processes are all around us. Standards have technological and economic benefits, such as making information exchange, production, and services more efficient. However, novel, innovative areas often either lack proper standards, or documents about standards in these areas are not available from a centralised platform or formal body (such as the International Standardisation Organisation).Systems and synthetic biology is a relatively novel area, and it is only in the last decade that the standardisation of data, information, and models related to systems and synthetic biology has become a community-wide effort. Several open standards have been established and are under continuous development as a community initiative. COMBINE, the ‘COmputational Modeling in BIology’ NEtwork [1] has been established as an umbrella initiative to coordinate and promote the development of the various community standards and formats for computational models. There are yearly two meeting, HARMONY (Hackathons on Resources for Modeling in Biology), Hackathon-type meetings with a focus on development of the support for standards, and COMBINE forums, workshop-style events with oral presentations, discussion, poster, and breakout sessions for further developing the standards. For more information see http://co.mbine.org/.So far the different standards were published and made accessible through the standards’ web-pages or preprint services. The aim of this special issue is to provide a single, easily accessible and citable platform for the publication of standards in systems and synthetic biology. This special issue is intended to serve as a central access point to standards and related initiatives in systems and synthetic biology, it will be published annually to provide an opportunity for standard development groups to communicate updated specifications.

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