scholarly journals Multiblock Copolymers of Norbornene and Cyclododecene: Chain Structure and Properties

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1756
Author(s):  
Yulia I. Denisova ◽  
Georgiy A. Shandryuk ◽  
Marianna P. Arinina ◽  
Ivan S. Levin ◽  
Vsevolod A. Zhigarev ◽  
...  
Keyword(s):  
First Generation ◽  
Average Length ◽  
Chain Structure ◽  
Random Copolymers ◽  
Multiblock Copolymers ◽  
Structure Property ◽  
Reaction Conditions ◽  
Property Relations ◽  
Cross Metathesis

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.

scholarly journals Olefin metathesis in multiblock copolymer synthesis

2019 ◽  
Vol 15 ◽  
pp. 218-235 ◽  
Author(s):  
Maria L Gringolts ◽  
Yulia I Denisova ◽  
Eugene Sh Finkelshtein ◽  
Yaroslav V Kudryavtsev
Keyword(s):  
Olefin Metathesis ◽  
Ring Opening ◽  
Mechanical Characteristics ◽  
Multiblock Copolymers ◽  
Structure Property ◽  
Practical Applications ◽  
Property Relations ◽  
Multiblock Copolymer ◽  
Cross Metathesis ◽  
Synthetic Approaches

Multiblock copolymers constitute a basis for an emerging class of nanomaterials that combine various functional properties with durability and enhanced mechanical characteristics. Our mini-review addresses synthetic approaches to the design of multiblock copolymers from unsaturated monomers and polymers using olefin metathesis reactions and other ways of chemical modification across double C=C bonds. The main techniques, actively developed during the last decade and discussed here, are the coupling of end-functionalized blocks, sequential ring-opening metathesis polymerization, and cross metathesis between unsaturated polymers, or macromolecular cross metathesis. The last topic attracts special interest due to its relative simplicity and broad opportunities to tailor the structure and hence the properties of the copolymer products. Whenever possible, we analyze the structure–property relations for multiblock copolymers and point to their possible practical applications.

scholarly journals Selective Ring Opening Allene Metathesis: Polymerization or Ruthenium Vinylidene Formation

2021 ◽  
Author(s):  
William Neary ◽  
Yunyan Sun ◽  
Jeffrey S. Moore
Keyword(s):  
Ring Opening ◽  
First Generation ◽  
Elevated Temperatures ◽  
Structure Property ◽  
Fluorescent Properties ◽  
Metathesis Polymerization ◽  
Good Thermal Stability ◽  
Isolation And Characterization ◽  
Selective Ring Opening

Selective ring-opening allene metathesis polymerization (ROAlMP) and ruthenium vinylidene formation from 1,2-cyclononadiene (<b>1</b>) by simple catalyst selection are discussed. Grubbs second generation catalyst (G2) favors the formation of an alkylidene leading to the ROAlMP of (<b>1</b>). Grubbs first generation catalyst (G1) favors vinylidene formation and prevents the homopolymerization of (<b>1</b>) even at elevated temperatures. Isolation and characterization of poly(<b>1</b>) by NMR analysis and MALDI-TOF confirms the generation of a well-defined polyallene that exhibits good thermal stability (<i>T</i><sub>D</sub> ca. 400 ºC) and fluorescent properties. Ring-opening metathesis polymerization (ROMP) of a high strained norbornene derivative (NBE-<sup>i</sup>Pr) at 80 ºC using the ruthenium vinylidene generated from (<b>1</b>) is also investigated. The discovery of ROAlMP allows for the simple accesses of well-defined polyallenes from commercially available catalysts and will ultimately guide structure-property determinations of polyallenes.

scholarly journals Catalyst Type Effects on Structure/Property Relations of Polypropylene Random Copolymers

2021 ◽  
pp. 2100302
Author(s):  
Christian Paulik ◽  
Cornelia Tranninger ◽  
Jingbo Wang ◽  
Pavel Shutov ◽  
Daniela Mileva ◽  
...  
Keyword(s):  
Random Copolymers ◽  
Structure Property ◽  
Property Relations ◽  
Catalyst Type

Characterization of Structure-Property Relations and Second Harmonic Generation of 6-Methoxy-2-Naphthaldehyde

2021 ◽  
pp. 1-13
Author(s):  
D. Rajaniverma ◽  
D. Jagadeeswara Rao ◽  
P. V. Prasanna Kumar ◽  
V. Seetaramaiah ◽  
Y. Ramakrishna
Keyword(s):  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Second Harmonic ◽  
Structure Property ◽  
Property Relations

scholarly journals Second Zagreb and Sigma Indices of Semi and Total Transformations of Graphs

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Zhen Yang ◽  
Micheal Arockiaraj ◽  
Savari Prabhu ◽  
M. Arulperumjothi ◽  
Jia-Bao Liu
Keyword(s):  
Physicochemical Properties ◽  
Molecular Graph ◽  
Vital Role ◽  
Topological Indices ◽  
The Novel ◽  
Structure Property ◽  
Bond Type ◽  
Property Relations

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.

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