Chain-length distribution functions of polymers after random degradation and cross-linking, with particular reference to elastomers

1953 ◽  
Vol 49 ◽  
pp. 1369 ◽  
Author(s):  
W. F. Watson
Keyword(s):  
Chain Length ◽  
Length Distribution ◽  
Distribution Functions ◽  
Cross Linking ◽  
Chain Length Distribution

Chain-Length Distribution Functions of Polymers after Random Degradation and Cross-Linking, with Particular Reference to Elastomers

1954 ◽  
Vol 27 (3) ◽  
pp. 629-633
Author(s):  
W. F. Watson
Keyword(s):  
Chain Length ◽  
Statistical Treatment ◽  
Length Distribution ◽  
Distribution Functions ◽  
Average Chain Length ◽  
Cross Linking ◽  
Chain Length Distribution ◽  
Polymer Formation ◽  
Chain Lengths

Abstract The distribution of chain lengths of polymers on formation, random degradation and random cross-linking, have been derived by a simple statistical treatment. Chain-length distribution functions for all cases are represented by special forms of the expression : Nx/N=(α+β+γ)exp[−(α+β+γ)x] where β is the reciprocal of the average chain length on polymer formation, α is the degree of random degradation, and γ is the degree of cross-linking.

Chain-Length Distribution Functions during Polymerization

1954 ◽  
Vol 27 (3) ◽  
pp. 622-628 ◽  
Author(s):  
W. F. Watson
Keyword(s):  
Reaction Mechanism ◽  
Chain Length ◽  
Length Distribution ◽  
Kinetic Scheme ◽  
Distribution Functions ◽  
Average Chain Length ◽  
Chain Length Distribution ◽  
Molecular Weights ◽  
Measurable Rate ◽  
Chain Lengths

Abstract Functions for the distribution of chain lengths of a polymer formed during polymerization have been evaluated in terms of the directly measurable rate and rate of initiation, or the single equivalent measurement of number-average chain length. No details of the reaction mechanism are required, except for the occurrence of termination by combination of polymer radicals. This is in contrast to the usual derivation of distribution functions from the postulated kinetic scheme. The three types of termination are considered, (1) combination absent, (2) combination predominant, and (3) a mixture of combination with other modes of termination. The application to copolymerization is outlined. Relationships between the various average molecular weights are considered.

Direct Observation of Chain Lengths and Conformations in Oligofluorene Distributions from Controlled Polymerization by Double Electron-Electron Resonance

2019 ◽  
Author(s):  
Dennis Bücker ◽  
Annika Sickinger ◽  
Julian D. Ruiz Perez ◽  
Manuel Oestringer ◽  
Stefan Mecking ◽  
...  
Keyword(s):  
Chain Length ◽  
Length Distribution ◽  
Catalyst System ◽  
Chain Conformation ◽  
Controlled Polymerization ◽  
Chain Length Distribution ◽  
Electron Resonance ◽  
Double Electron ◽  
The Individual ◽  
Double Electron Electron Resonance

Synthetic polymers are mixtures of different length chains, and their chain length and chain conformation is often experimentally characterized by ensemble averages. We demonstrate that Double-Electron-Electron-Resonance (DEER) spectroscopy can reveal the chain length distribution, and chain conformation and flexibility of the individual n-mers in oligo-(9,9-dioctylfluorene) from controlled Suzuki-Miyaura Coupling Polymerization (cSMCP). The required spin-labeled chain ends were introduced efficiently via a TEMPO-substituted initiator and chain terminating agent, respectively, with an in situ catalyst system. Individual precise chain length oligomers as reference materials were obtained by a stepwise approach. Chain length distribution, chain conformation and flexibility can also be accessed within poly(fluorene) nanoparticles.

scholarly journals Miniaturized Analysis of Amylopectin Chain Length Distribution by Fluorescence-Assisted Capillary Electrophoresis (FACE) down to Single Starch Granules

2021 ◽  
Author(s):  
amandine pruvost ◽  
stanislas helle ◽  
nicolas szydlowski ◽  
Christian ROLANDO
Keyword(s):  
Capillary Electrophoresis ◽  
Chain Length ◽  
Solid Phase ◽  
Potato Starch ◽  
Relative Proportion ◽  
Length Distribution ◽  
Fluorescence Analysis ◽  
Starch Granules ◽  
Chain Length Distribution ◽  
Single Granule

In the present work, we developed a miniaturized method for determining amylopectin chain length distribution (CLD) by fluorescence-assisted capillary electrophoresis (FACE). The method relies on single granule entrapping into capillaries followed by direct starch gelatinization and amylopectin debranching on carbograph-based solid phase extraction (SPE) cartridges. Sample desalting on HypersepTM tips following APTS-labelling and the use of nanovials allowed for the fluorescence analysis of weakly diluted samples. Consequently, method sensitivity was improved by 500-fold which is compatible with the analysis of single potato starch granules. The method was implemented to determine CLD profiles of single starch granules ranging from 50 to 100 µm in diameter. In these experiments, the relative proportion of starch glucans of up to 30 degrees of polymerization (DP) could be quantified.

Chain Length Distribution of Amylopectins of Double- and Triple-Mutants Containing the Waxy Gene in the Inbred Oh43 Maize Background

1987 ◽  
Vol 39 (9) ◽  
pp. 295-298 ◽  
Author(s):  
H. Fuwa ◽  
D. V. Glover ◽  
K. Miyaura ◽  
N. Inouchi ◽  
Y. Konishi ◽  
...  
Keyword(s):  
Chain Length ◽  
Length Distribution ◽  
Waxy Gene ◽  
Chain Length Distribution
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