scholarly journals Temperature-dependent modulation by biaryl-based monomers of the chain length and morphology of biphenyl-based supramolecular polymers

2021 ◽  
Author(s):  
E. W. Meijer ◽  
Lafayette L.N.J. De Windt ◽  
Brigitte Lamers ◽  
Elisabeth E. Weyandt ◽  
Mark Antonius Johannes Koenis ◽  
...  
Keyword(s):  
Chain Length ◽  
Functional Diversity ◽  
Polymer Materials ◽  
Supramolecular Polymers ◽  
Supramolecular Polymer ◽  
Structure Property ◽  
Temperature Dependent ◽  
Structure Property Relationships

Supramolecular copolymerizations offer attractive options to introduce structural and functional diversity in supramolecular polymer materials. Yet, general principles and structure-property relationships for rational comonomer design remain lacking. Here, we report...

Structure-property relationships of PE/PP sandwiched films

1987 ◽  
Vol 45 ◽  
pp. 454-455
Author(s):  
J. Petermann ◽  
G. Broza ◽  
U. Rieck ◽  
A. Jaballah ◽  
A. Kawaguchi
Keyword(s):  
Mechanical Tests ◽  
Polymer Materials ◽  
Ionic Crystals ◽  
Structure Property ◽  
Polymer Systems ◽  
Structure Property Relationships ◽  
Oriented Films ◽  
Materials Used ◽  
Polymer Laminates ◽  
Heated Glass

Oriented overgrowth of polymer materials onto ionic crystals is well known and recently it was demonstrated that this epitaxial crystallisation can also occur in polymer/polymer systems, under certain conditions. The morphologies and the resulting physical properties of such systems will be presented, especially the influence of epitaxial interfaces on the adhesion of polymer laminates and the mechanical properties of epitaxially crystallized sandwiched layers.Materials used were polyethylene, PE, Lupolen 6021 DX (HDPE) and 1810 D (LDPE) from BASF AG; polypropylene, PP, (PPN) provided by Höchst AG and polybutene-1, PB-1, Vestolen BT from Chemische Werke Hüls. Thin oriented films were prepared according to the method of Petermann and Gohil, by winding up two different polymer films from two separately heated glass-plates simultaneously with the help of a motor driven cylinder. One double layer was used for TEM investigations, while about 1000 sandwiched layers were taken for mechanical tests.

On the nature of the phase transitions of aluminosilicate perrhenate sodalite

2020 ◽  
Vol 235 (6-7) ◽  
pp. 213-223
Author(s):  
Hilke Petersen ◽  
Lars Robben ◽  
Thorsten M. Gesing
Keyword(s):  
Raman Spectroscopy ◽  
Phase Transitions ◽  
Decomposition Temperature ◽  
Second Phase ◽  
Structure Property ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Two Phase ◽  
Structure Property Relationships ◽  
Heat Capacity Measurements

AbstractThe temperature-dependent structure-property relationships of the aluminosilicate perrhenate sodalite |Na8(ReO4)2|[AlSiO4]6 (ReO4-SOD) were analysed via powder X-ray diffraction (PXRD), Raman spectroscopy and heat capacity measurements. ReO4-SOD shows two phase transitions in the investigated temperature range (13 K < T < 1480 K). The first one at 218.6(1) K is correlated to the transition of dynamically ordered $P\overline{4}3n$ (> 218.6(1 K) to a statically disordered (<218.6(1) K) SOD template in $P\overline{4}3n$. The loss of the dynamics of the template anion during cooling causes an increase of disorder, indicated by an unusual intensity decrease of the 011-reflection and an increase of the Re-O2 bond length with decreasing temperature. Additionally, Raman spectroscopy shows a distortion of the ReO4 anion. Upon heating the thermal expansion of the sodalite cage originated in the tilt-mechanism causes the second phase transition at 442(1) K resulting in a symmetry-increase from $P\overline{4}3n$ to $Pm\overline{3}n$, the structure with the sodalites full framework expansion. Noteworthy is the high decomposition temperature of 1320(10) K.

Elastomeric Polyether-Ester Block Copolymers. I. Structure-Property Relationships of Tetramethylene Terephthalate/Polyether Terephthalate Copolymers

1977 ◽  
Vol 50 (4) ◽  
pp. 688-703 ◽  
Author(s):  
J. R. Wolfe
Keyword(s):  
Phase Separation ◽  
Melting Point ◽  
Block Copolymers ◽  
Low Temperature ◽  
Chain Length ◽  
Chemical Structure ◽  
High Water ◽  
Structure Property ◽  
Tear Strength ◽  
Structure Property Relationships

Abstract The properties of elastomeric tetramethylene terephthalate/polyether terephthalate copolymers have been related to the chemical structure, chain length, and concentration in the copolymers of the PTMEG-, PEG-, and PPG-derived polyether units. Low-temperature properties and tear strength are dependent on all three polyether-related variables. Melting point, hardness, and stress at 100% elongation appear to be independent of polyether structure. Polyether glycols of low MW volatilize during copolymer preparation. High-MW polyethers tend to crystallize when present in the copolymers. Polyether glycols of intermediate MW (∼ 1000) yield copolymers with the best resistance to low-temperature stiffening. Copolymer synthesis is most difficult with PPG as the polyether glycol. Inherent viscosities are low, and phase separation occurs at lower polyether MW than with PTMEG or PEG. The PEG-based copolymers exhibit high water swell, particularly at intermediate and high PEG MW. The PTMEG-based copolymers are easiest to synthesize and exhibit the best overall combination of properties.

scholarly journals Yellow electrochromic polymer materials with fine tuning electrofluorescences by adjusting steric hindrance of side chains

RSC Advances ◽  
2017 ◽  
Vol 7 (41) ◽  
pp. 25444-25449 ◽  
Author(s):  
Jian Liu ◽  
Yuchen Shi ◽  
Jingchuan Wu ◽  
Mei Li ◽  
Jianming Zheng ◽  
...  
Keyword(s):  
Steric Hindrance ◽  
External Potential ◽  
Polymer Materials ◽  
Fine Tuning ◽  
Side Chains ◽  
Structure Property ◽  
Structure Property Relationships ◽  
Electrochromic Polymer

A series of novel conducting conjugated yellow-to-transmissive electrochromic (EC) polymers were designed to research their structure–property relationships, achieving electrofluorescent (EF) switching with applied external potential.

scholarly journals Mapping Temperature-Dependent Energy-Structure-Property Relationships for Solid Solutions of Inorganic Halide Perovskites

2020 ◽  
Author(s):  
Jack Yang
Keyword(s):  
Solid Solutions ◽  
Band Gaps ◽  
Energy Structure ◽  
Material Research ◽  
Structure Property ◽  
Temperature Dependent ◽  
Orbital Interactions ◽  
Structure Property Relationships ◽  
Data Driven Approach ◽  
Halide Perovskites

Formation of solid solutions with complex compositions has been exhaustively adopted in material research for improving chemical and physical properties. This is also the true for halide perovskites, in the hope of further enhancing their stabilities and reducing the toxicities in lead-containing compounds. Replacement of lead with tin, even partially, is a route to achieve the latter goal. However, this has to be compromised with reduction in band gaps as well as structural stabilities. High-throughput statistical samplings over different configurations for random solid solutions have played pivotal roles in guiding the chemical designs of halide perovskite with better stabilities while retaining high photovoltaic efficiencies, but it remains challenging to intuitively and comprehensively understand the intriguing energy-structure-property (ESP) relationships in solid solutions encompassing multiple degrees-of-freedoms. In this work, first--principle dynamic and electronic structure calculations are performed across 51 different compositions of Cs(Pb$_{x}$Sn$_{1-x}$)X$_{3}$ (X=Cl, Br and I), to systematically reveal the compositional and temperature dependent stabilities, vibrational anharmonicities and band gaps in solid solutions of halide perovskites. This is enabled, in particular, by applying a recently proposed `anharmonicity score' that provides a single numerical metric to characterise the structural dynamics in a multi-atomic system. Further combination with unsupervised machine-learning enable us to produce an ESP map to visually correlate the anharmonicity score with structural distortions and energies. However, temperature-dependent variations in band gap energies, which strongly depend on orbital interactions in metal-halide octrahedra, do not necessarily follow the same trend as anharmonicity scores. This work represents our latest developments in applying data--driven approach to establish ESP relationships for guiding the future designs of functional perovskites.

Structure-property relationships in ILs: A study of the alkyl chain length dependence in vaporisation enthalpies of pyridinium based ionic liquids

2012 ◽  
Vol 55 (8) ◽  
pp. 1525-1531 ◽  
Author(s):  
Dzmitry H. Zaitsau ◽  
Andrei V. Yermalayeu ◽  
Vladimir N. Emel’yanenko ◽  
Sergey P. Verevkin ◽  
Urs Welz-Biermann ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Chain Length ◽  
Alkyl Chain ◽  
Alkyl Chain Length ◽  
Structure Property ◽  
Length Dependence ◽  
Structure Property Relationships

scholarly journals Mapping temperature-dependent energy–structure–property relationships for solid solutions of inorganic halide perovskites

2020 ◽  
Vol 8 (47) ◽  
pp. 16815-16825
Author(s):  
Jack Yang
Keyword(s):  
Machine Learning ◽  
Solid Solutions ◽  
Finite Temperature ◽  
Energy Structure ◽  
Structure Property ◽  
Temperature Dependent ◽  
Unsupervised Machine Learning ◽  
Structure Property Relationships ◽  
Electronic Dynamics ◽  
Halide Perovskites

We explored how lead/tin mixing affects the finite-temperature stabilities, atomistic and electronic dynamics of inorganic halide perovskites, with the aid of unsupervised machine learning and the recently devised anharmonicity score.

scholarly journals Understanding structure–property relationships of main chain cyclopropane in linear polyesters

2020 ◽  
Vol 11 (39) ◽  
pp. 6251-6258
Author(s):  
Connor J. Stubbs ◽  
Andrew P. Dove
Keyword(s):  
Main Chain ◽  
Effective Means ◽  
Polymer Materials ◽  
Structure Property ◽  
Bulk Properties ◽  
Rigid Ring ◽  
Structure Property Relationships ◽  
Ring Structures

Rigid ring structures have gained increasing interest in the polymer materials community as an effective means to manipulate bulk properties. Here, we investigate structure–property relationships of the smallest ring: cyclopropane.

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