The Characterization of the Structure-Property Relations of Electron Beam Cured Composites

2004 ◽  
Author(s):  
Roger J. Morgan
Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1756
Author(s):  
Yulia I. Denisova ◽  
Georgiy A. Shandryuk ◽  
Marianna P. Arinina ◽  
Ivan S. Levin ◽  
Vsevolod A. Zhigarev ◽  
...  

We investigate the structure–property relations of the multiblock copolymers of norbornene with cyclododecene synthesized via the macromolecular cross-metathesis reaction between amorphous polynorbornene and semicrystalline polydodecenamer in the presence of the first-generation Grubbs catalyst. By adjusting the reaction time, catalyst amount, and composition of the initial system, we obtain a set of statistical multiblock copolymers that differ in the composition and average length of norbornene and dodecenylene unit sequences. Structural, thermal, and mechanical characterization of the copolymers with NMR, XRD, DSC (including thermal fractionation by successive self-nucleation and annealing), and rotational rheology allows us to relate the reaction conditions to the average length of crystallizable unit sequences, thicknesses of corresponding lamellas, and temperatures of their melting. We demonstrate that isolated dodecenylene units can be incorporated into crystalline lamellas so that even nearly random copolymers should retain crystallinity. Weak high-temperature endotherms observed in the multiblock copolymers of norbornene with cyclododecene and other cycloolefins could indicate that the corresponding systems are microphase-separated in the melt state.


Author(s):  
D. Rajaniverma ◽  
D. Jagadeeswara Rao ◽  
P. V. Prasanna Kumar ◽  
V. Seetaramaiah ◽  
Y. Ramakrishna

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Zhen Yang ◽  
Micheal Arockiaraj ◽  
Savari Prabhu ◽  
M. Arulperumjothi ◽  
Jia-Bao Liu

The study of structure-property relations including the transformations of molecules is of utmost importance in correlations with corresponding physicochemical properties. The graph topological indices have been used effectively for such study and, in particular, bond-based indices play a vital role. The bond-additive topological indices of a molecular graph are defined as a sum of edge measures over all edges in which edge measures can be computed based on degrees, closeness, peripherality, and irregularity. In this study, we provide the mathematical characterization of the transformation of a structure that can be accomplished by the novel edge adjacency and incidence relations. We derive the exact expressions of bond type indices such as second Zagreb, sigma indices, and their coindices of total transformation and two types of semitransformations of the molecules which in turn can be used to characterize the topochemical and topostructural properties.


2012 ◽  
Vol 206 (13) ◽  
pp. 3094-3103 ◽  
Author(s):  
Daniel A. Grave ◽  
Zachary R. Hughes ◽  
Joshua A. Robinson ◽  
Thomas P. Medill ◽  
Matthew J. Hollander ◽  
...  

1999 ◽  
Vol 577 ◽  
Author(s):  
William B. Yelon

ABSTRACTNeutron diffraction has been invaluable in the characterization of intermetallic magnetic phases due to the unique properties of the neutron and the availability of high performance powder diffractometers that allow large numbers of samples to be investigated. The structural data derived from these studies serves as fundamental input for theory, and constraints on analyses of data from other methods, such as Mossbauer spectroscopy. The empirical structure-property relations derived from these studies serves to guide synthesis of new compounds and may help to define the next generation of high performance permanent magnets.


Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1912
Author(s):  
Karolina Bujak ◽  
Anna Kozanecka-Szmigiel ◽  
Ewa Schab-Balcerzak ◽  
Jolanta Konieczkowska

This paper describes the synthesis and characterization of new “T-type” azo poly(amide imide)s as well as guest-host systems based on the “T-type” matrices. The matrices possessed pyridine rings in a main-chain and azobenzene moieties located either between the amide or imide groups. The non-covalent polymers contained the molecularly dispersed 4-phenylazophenol or 4-[(4-methyl phenyl)diazinyl]phenol chromophores that are capable of forming intermolecular hydrogen bonds with the pyridine rings. The FTIR spectroscopy and the measurements of the thermal, optical and photoinduced optical birefringence were employed for the determination of the influence of H-bonds and the specific elements of polymer architecture on physicochemical properties. Moreover, the obtained results were compared to those described in our previous works to formulate structure-property relations that may be considered general for the class of “T-type” azo poly(amide imide)s.


Author(s):  
J. I. Bennetch

In a recent study of the superplastic forming (SPF) behavior of certain Al-Li-X alloys, the relative misorientation between adjacent (sub)grains proved to be an important parameter. It is well established that the most accurate way to determine misorientation across boundaries is by Kikuchi line analysis. However, the SPF study required the characterization of a large number of (sub)grains in each sample to be statistically meaningful, a very time-consuming task even for comparatively rapid Kikuchi analytical techniques.In order to circumvent this problem, an alternate, even more rapid in-situ Kikuchi technique was devised, eliminating the need for the developing of negatives and any subsequent measurements on photographic plates. All that is required is a double tilt low backlash goniometer capable of tilting ± 45° in one axis and ± 30° in the other axis. The procedure is as follows. While viewing the microscope screen, one merely tilts the specimen until a standard recognizable reference Kikuchi pattern is centered, making sure, at the same time, that the focused electron beam remains on the (sub)grain in question.


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