Determination of the Swelling Ratio of Poly(Urea-urethane) Microcapsules by Single-Particle Light Scattering

Langmuir ◽  
2001 ◽  
Vol 17 (15) ◽  
pp. 4525-4528 ◽  
Author(s):  
Toshiaki Dobashi ◽  
Toshiaki Furukawa ◽  
Takayuki Narita ◽  
Shinsuke Shimofure ◽  
Kimio Ichikawa ◽  
...  
Keyword(s):  
Light Scattering ◽  
Single Particle ◽  
Swelling Ratio

Determination of single-particle relaxation time from light scattering spectra in modulation-doped quantum wells

1987 ◽  
Vol 36 (3) ◽  
pp. 1565-1569 ◽  
Author(s):  
G. Fasol ◽  
N. Mestres ◽  
M. Dobers ◽  
A. Fischer ◽  
K. Ploog
Keyword(s):  
Relaxation Time ◽  
Light Scattering ◽  
Quantum Wells ◽  
Single Particle ◽  
Scattering Spectra

Preparation of graft copolymers by the reaction of polymeric acyl chlorides with monohydroxy-terminated polymers: An introductory study

1988 ◽  
Vol 53 (8) ◽  
pp. 1735-1744 ◽  
Author(s):  
Jitka Horská ◽  
Jaroslav Stejskal ◽  
Pavel Kratochvíl ◽  
Aubrey D. Jenkins ◽  
Eugenia Tsartolia ◽  
...  
Keyword(s):  
Light Scattering ◽  
Chemical Composition ◽  
Statistical Model ◽  
Graft Copolymers ◽  
Coupling Reaction ◽  
Molecular Characteristics ◽  
Gel Formation ◽  
Acyl Chlorides ◽  
Molecular Weights

An attempt was made to prepare well-defined graft copolymers by the coupling reaction between acyl chloride groups located along the backbone chain and monohydroxy-terminated grafts prepared separately. The molecular weights and the parameters of heterogeneity in chemical composition of the products were determined by light scattering and osmometry. The determination of molecular characteristics revealed that the degree of grafting was low. The results therefore could not be confronted with a statistical model at this stage. The problems encountered in the synthesis, e.g., gel formation, and the data relating to the soluble products are discussed.

Effect and Detection of Loose Chain Ends in Crosslinked Polyurethane Elastomers

1971 ◽  
Vol 44 (1) ◽  
pp. 152-165 ◽  
Author(s):  
A. E. Oberth
Keyword(s):  
Crosslink Density ◽  
Volume Fraction ◽  
Present Theory ◽  
Swelling Ratio ◽  
Polyurethane Elastomers ◽  
Equilibrium Volume ◽  
Equilibrium Swelling ◽  
Volume Swelling

Abstract The effect of loose chain ends on tensile properties and equilibrium swelling of crosslinked polyurethane rubbers is studied. As in plasticized elastomers, tensile strength and elastic modulus are reduced approximately by a factor (1−νE,P)2, where νE,P is the volume fraction of loose chain ends, plasticizer, or both. This effect is much larger than predicted by present theory. Also the equilibrium volume swelling ratio, V0/V, of rubbers having terminal chains or an equal volume of plasticizer is the same, provided they do not differ in crosslink density. However, the volume fraction of “network rubber” in the equilibrium swollen specimen, ν2, differs owing to the non-extractability of terminal chains. On this basis a method is proposed which allows experimental determination of the volume fraction of loose ends. Elastomers abounding in loose chain ends show markedly less long term stress relaxation. This effect is not clearly understood but is useful to detect the presence of non load-bearing network.

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