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Dynamic viscoelastic measurements of photosensitive polymers
Author(s) -
Watanabe Koichiro,
Amari Takeshi,
Otsubo Yasufumi
Publication year - 1984
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1984.070290106
Subject(s) - benzoin , materials science , viscoelasticity , polymer , curing (chemistry) , acrylate , composite material , irradiation , polymerization , dynamic mechanical analysis , rheometer , rheology , polymer chemistry , copolymer , physics , nuclear physics
A new type of rheometer for measuring the dynamic viscoelastic properties of photosensitive polymers was developed. When the photosensitive polymer is exposed to ultraviolet (UV) irradiation, the dynamic modulus and dynamic viscosity increase with time due to network polymerization. Since the curing is completed within a few seconds, the apparatus is designed to follow the rapid changes in rheological properties. The most significant advantages of this apparatus are as follows: (1) The required amount of sample is extremely small (about 0.01 mg). (2) Although the measurements are carried out with liquid polymer, a cell for sample is not necessary. (3) Since the sample thickness is about 10 μm, the temperature can be easily controlled. (4) By measuring the thickness before and after UV irradiation, the volume contraction of the sample can be determined. The curing behavior is measured for urethane acrylate and epoxy acrylate prepolymers, and the effect of acetophenone and benzoin which act as photoinitiators, is examined. Acetophenone ensures more efficient absorption of UV light than benzoin.