18—THE EFFECT OF ALKALIS ON THE MOLECULAR CHAIN LENGTH OF CHEMICALLY MODIFIED COTTON CELLULOSES, AS SHOWN BY FLUIDITY MEASUREMENTS ON THE DERIVED NITROCELLULOSES

1938 ◽  
Vol 29 (9) ◽  
pp. T195-T218 ◽  
Author(s):  
G. F. Davidson
Keyword(s):  
Chain Length ◽  
Molecular Chain ◽  
Chemically Modified

Mechanical Chain-Scission in Rubber Vulcanizate at Low Temperatures

1979 ◽  
Vol 52 (4) ◽  
pp. 773-780 ◽  
Author(s):  
T. Kusano ◽  
K. Kobayashl ◽  
K. Murakami
Keyword(s):  
Free Radicals ◽  
Chain Length ◽  
Low Temperatures ◽  
Crosslink Density ◽  
Glassy State ◽  
Chain Scission ◽  
Molecular Chain ◽  
Yield Strain ◽  
Air Stream ◽  
Intermolecular Reaction

Abstract When vulcanized natural rubbers are forced to extend in the glassy state, free radicals are produced by the scission of the primary chain. The amount of the free radicals increases with the strain. The tensile yield strain decreases with the decrease of the molecular chain length between crosslinks. This behavior is explainable on the basis of the limited chain extensibility. The extended chains are broken with further increases of the strain. The mechanically produced free radicals are quite stable below about −40°C. The crosslink density of the chain-ruptured material increases about 2∼3×10−5 mol/cm3. This fact shows that the free radicals are consumed not only by recombination but by the intermolecular reaction. In both sulfur and DCP vulcanizates, the network chains rather than the crosslinks are broken by stretching. In an air stream, some free radicals react with oxygen and others form crosslinks.

Properties of Cotton Fabrics Crosslinked with Different Molecular Chain Lengths of Aldehyde Agents

1992 ◽  
Vol 62 (9) ◽  
pp. 547-551 ◽  
Author(s):  
Tsang-Yuh Liang ◽  
Jenn-Yann Hwang ◽  
Der-Shiann Ju ◽  
Cheng-Chi Chen
Keyword(s):  
Activation Energy ◽  
Chain Length ◽  
Cotton Fabric ◽  
Crosslinking Agent ◽  
Cotton Fabrics ◽  
Molecular Chain ◽  
Diffusion Resistance ◽  
Adsorption Time ◽  
Untreated Cotton ◽  
Chain Lengths

Adsorption time curves from finite baths have been studied for untreated cotton fabric and cottons treated with differing molecular chain lengths of aldehydes (formaldehyde and glutaraldehyde). Crosslinking reduced the rate constant, structural diffusion resistance constant, and equilibrium adsorption of dyeing. Additionally, these data decreased with increasing agent concentration and with increasing molecular chain length of the crosslinking agent. The dyeing activation energy of the glutaraldehyde treated fabric was lower than that of the formaldehyde treated fabric.

Thermal transport in electrospun vinyl polymer nanofibers: effects of molecular weight and side groups

Soft Matter ◽  
2018 ◽  
Vol 14 (47) ◽  
pp. 9534-9541 ◽  
Author(s):  
Yin Zhang ◽  
Xin Zhang ◽  
Lin Yang ◽  
Qian Zhang ◽  
Matthew L. Fitzgerald ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Molecular Weight ◽  
Chain Length ◽  
Thermal Transport ◽  
Molecular Chain ◽  
Polymer Nanofibers ◽  
Vinyl Polymer

Thermal conductivity increases with molecular chain length for PE nanofibers, and is higher for vinyl polymer nanofibers with lighter and more symmetric side groups.

Development of a novel microviscosity model based on molecular chain length

2014 ◽  
Vol 21 (5) ◽  
pp. 1121-1130 ◽  
Author(s):  
Yan Lou ◽  
Jiulong Pei ◽  
Peiqian He ◽  
Xiaoyu Wu
Keyword(s):  
Chain Length ◽  
Molecular Chain ◽  
Model Based
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