A comparative study of structure–property relationships in highly oriented thermoplastic and thermotropic polyesters with different chemical structures

2006 ◽  
Vol 100 (1) ◽  
pp. 142-160 ◽  
Author(s):  
Ismail Karacan
Keyword(s):  
Comparative Study ◽  
Structure Property ◽  
Chemical Structures ◽  
Structure Property Relationships

scholarly journals A general approach for retrosynthetic molecular core analysis

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
J. Jesús Naveja ◽  
B. Angélica Pilón-Jiménez ◽  
Jürgen Bajorath ◽  
José L. Medina-Franco
Keyword(s):  
Single Molecule ◽  
Chemical Space ◽  
Significant Proportion ◽  
Bipartite Network ◽  
Data Sets ◽  
Structure Property ◽  
Data Set ◽  
Chemical Structures ◽  
Structure Property Relationships ◽  
Analog Series

Abstract Scaffold analysis of compound data sets has reemerged as a chemically interpretable alternative to machine learning for chemical space and structure–activity relationships analysis. In this context, analog series-based scaffolds (ASBS) are synthetically relevant core structures that represent individual series of analogs. As an extension to ASBS, we herein introduce the development of a general conceptual framework that considers all putative cores of molecules in a compound data set, thus softening the often applied “single molecule–single scaffold” correspondence. A putative core is here defined as any substructure of a molecule complying with two basic rules: (a) the size of the core is a significant proportion of the whole molecule size and (b) the substructure can be reached from the original molecule through a succession of retrosynthesis rules. Thereafter, a bipartite network consisting of molecules and cores can be constructed for a database of chemical structures. Compounds linked to the same cores are considered analogs. We present case studies illustrating the potential of the general framework. The applications range from inter- and intra-core diversity analysis of compound data sets, structure–property relationships, and identification of analog series and ASBS. The molecule–core network herein presented is a general methodology with multiple applications in scaffold analysis. New statistical methods are envisioned that will be able to draw quantitative conclusions from these data. The code to use the method presented in this work is freely available as an additional file. Follow-up applications include analog searching and core structure–property relationships analyses.

Structure–property relationships of PCGTA welds of Inconel X750 in as-welded and post-weld heat treated conditions—A comparative study

2015 ◽  
Vol 20 ◽  
pp. 1-14 ◽  
Author(s):  
K. Devendranath Ramkumar ◽  
S. Rahul Krishnan ◽  
R. Ramanand ◽  
S. Logesh ◽  
Tushar Satyandas ◽  
...  
Keyword(s):  
Comparative Study ◽  
Structure Property ◽  
Structure Property Relationships ◽  
Heat Treated ◽  
Inconel X750 ◽  
Weld Heat

scholarly journals Surface Modification by Polyzwitterions of the Sulfabetaine-Type, and Their Resistance to Biofouling

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1014 ◽  
Author(s):  
Eric Schönemann ◽  
André Laschewsky ◽  
Erik Wischerhoff ◽  
Julian Koc ◽  
Axel Rosenhahn
Keyword(s):  
Structural Diversity ◽  
Negative Control ◽  
Butyl Methacrylate ◽  
Structure Property ◽  
High Molar Mass ◽  
Zwitterionic Polymers ◽  
Chemical Structures ◽  
Structure Property Relationships ◽  
Repeat Units ◽  
The Individual

Films of zwitterionic polymers are increasingly explored for conferring fouling resistance to materials. Yet, the structural diversity of polyzwitterions is rather limited so far, and clear structure-property relationships are missing. Therefore, we synthesized a series of new polyzwitterions combining ammonium and sulfate groups in their betaine moieties, so-called poly(sulfabetaine)s. Their chemical structures were varied systematically, the monomers carrying methacrylate, methacrylamide, or styrene moieties as polymerizable groups. High molar mass homopolymers were obtained by free radical polymerization. Although their solubilities in most solvents were very low, brine and lower fluorinated alcohols were effective solvents in most cases. A set of sulfabetaine copolymers containing about 1 mol % (based on the repeat units) of reactive benzophenone methacrylate was prepared, spin-coated onto solid substrates, and photo-cured. The resistance of these films against the nonspecific adsorption by two model proteins (bovine serum albumin—BSA, fibrinogen) was explored, and directly compared with a set of references. The various polyzwitterions reduced protein adsorption strongly compared to films of poly(n‑butyl methacrylate) that were used as a negative control. The poly(sulfabetaine)s showed generally even somewhat higher anti-fouling activity than their poly(sulfobetaine) analogues, though detailed efficacies depended on the individual polymer–protein pairs. Best samples approach the excellent performance of a poly(oligo(ethylene oxide) methacrylate) reference.

A Comparative Study of the Structure/Property Relationships of Langmuir-Blodgett and Spin-Cast Films of an Amphiphilic, Regioregular Polythiophene Polymer

2006 ◽  
Vol 949 ◽  
Author(s):  
Jusroop Mattu ◽  
Thomas Johansson ◽  
Steven Holdcroft ◽  
Gary W. Leach
Keyword(s):  
Thin Films ◽  
Comparative Study ◽  
Conjugated Polymer ◽  
Structure Property ◽  
Materials Properties ◽  
Langmuir Blodgett ◽  
Thermal Reactivity ◽  
Structure Property Relationships ◽  
Structural Conformation ◽  
Cast Films

ABSTRACTThe effects of structural conformation and order on materials properties and reactivity in thin films of an amphiphilic, regioregular polythiophene π-conjugated polymer (πCP) derivative are presented. Thin films deposited by the Langmuir Blodgett technique provide highly ordered anisotropic films compared to those deposited by spin cast methods. Large differences in both the thermal reactivity and physical properties of the films are observed.

The Relation between Structure and Physical Properties in Polyurethans

1962 ◽  
Vol 35 (4) ◽  
pp. 970-1012 ◽  
Author(s):  
Takehide Tanaka ◽  
Tetsuo Yokoyama
Keyword(s):  
Physical Properties ◽  
Polymer Structure ◽  
Structure And Properties ◽  
Structure Property ◽  
Chemical Structures ◽  
Structure Property Relationships ◽  
Polymer Properties ◽  
Wide Range ◽  
Number Of Publications ◽  
Broad Region

Abstract The field of polyurethans is rapidly growing in commercial importance, especially in form and elastomer applications. This group of polymers includes a very broad region of chemical structures and chain length. In many cases polyurethans are synthesized from polyester glycols or polyether glycols and diisocyanates so that the urethan groups are even fewer in number than other functional groups. This process of synthesis enables us to deal with a very wide range of polymer properties, adding interest to the studies of relation between structure and properties. Though a considerable number of publications dealing primarily with the properties of urethan polymers have been published, few of them contribute to better understanding of the relation between these properties and the corresponding polymer structure. Within the last few years information of value has become available, and Saunders has established some semi-quantitative relations by the use of such data. He also discusses in his reports general considerations concerning structure-property relationships. Although his considerations and conclusions show a marked progress, they are not theoretically satisfactory yet, especially from a quantitative viewpoint. The authors have investigated structure-property relationships in polyurethans for a few years and written some papers concerning synthesis, reaction kinetics, some physical properties, network structure, and dynamic behavior of polyurethans.

scholarly journals Relationships between chemical structure, mechanical properties and materials processing in nanopatterned organosilicate fins

2017 ◽  
Vol 8 ◽  
pp. 863-871 ◽  
Author(s):  
Gheorghe Stan ◽  
Richard S Gates ◽  
Qichi Hu ◽  
Kevin Kjoller ◽  
Craig Prater ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Structure ◽  
Electrical Characterization ◽  
Inverse Correlation ◽  
Structure Characterization ◽  
Structure Property ◽  
Chemical Structures ◽  
Structure Property Relationships ◽  
Nanoscale Characterization ◽  
20 Nm

The exploitation of nanoscale size effects to create new nanostructured materials necessitates the development of an understanding of relationships between molecular structure, physical properties and material processing at the nanoscale. Numerous metrologies capable of thermal, mechanical, and electrical characterization at the nanoscale have been demonstrated over the past two decades. However, the ability to perform nanoscale molecular/chemical structure characterization has only been recently demonstrated with the advent of atomic-force-microscopy-based infrared spectroscopy (AFM-IR) and related techniques. Therefore, we have combined measurements of chemical structures with AFM-IR and of mechanical properties with contact resonance AFM (CR-AFM) to investigate the fabrication of 20–500 nm wide fin structures in a nanoporous organosilicate material. We show that by combining these two techniques, one can clearly observe variations of chemical structure and mechanical properties that correlate with the fabrication process and the feature size of the organosilicate fins. Specifically, we have observed an inverse correlation between the concentration of terminal organic groups and the stiffness of nanopatterned organosilicate fins. The selective removal of the organic component during etching results in a stiffness increase and reinsertion via chemical silylation results in a stiffness decrease. Examination of this effect as a function of fin width indicates that the loss of terminal organic groups and stiffness increase occur primarily at the exposed surfaces of the fins over a length scale of 10–20 nm. While the observed structure–property relationships are specific to organosilicates, we believe the combined demonstration of AFM-IR with CR-AFM should pave the way for a similar nanoscale characterization of other materials where the understanding of such relationships is essential.

The Effect of Graphene Oxide Dispersion on Structure-Property Relationships in Graphene-Based Polymer Nanocomposites

2020 ◽  
Vol 65 ◽  
pp. 97-121
Author(s):  
Haia Aldosari
Keyword(s):  
Graphene Oxide ◽  
Polymer Nanocomposites ◽  
Degree Of Crystallinity ◽  
Structure Property ◽  
Initial State ◽  
Host Matrix ◽  
Property Relations ◽  
Chemical Structures ◽  
Structure Property Relationships ◽  
Nanoparticles Dispersion

The performance of graphene/polymer nanocomposites depends on many factors but the major factor is a nanoparticles dispersion and distribution into the host matrix. The present work investigates the effect of the dispersion of graphene oxide upon the structure-property relations in metallocene linear low density polyethylene (PE), homo polypropylene (PP), and blends thereof. These nanocomposites were prepared by solvent processing, where DMF and o-xylene were used as solvents for Graphene Oxide (GO) powder and the polymers respectively, before the two components were combined to form a well-mixed initial state. Characterization of the structure and crystallization of the nanocomposites was carried out by small- and wide-angle X-ray scattering and diffraction (SAXS and WAXD). The chemical structures were characterized by Fourier transform infrared spectroscopy (FTIR) and by Raman spectroscopy, and the latter used to calculate the ID/IG value for a pure GO samples. The thermal properties of the resulting nanocomposites were investigated by DSC and TGA in order to obtain Melting temperature ( ), crystallization temperature ( ) and degree of crystallinity ( ) as well as a range of degradation temperatures. The effect of GO on the mechanical properties was studied via the ultimate tensile strength and elastic modulus.

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