Acrylic acid polymerization and its graft copolymerization to poly(ethylene oxide) by gamma rays
Free radical initiated polymerization of acrylic acid was investigated in methanol-water solutions with and without poly(ethylene oxide) (PEO). The formation of poly(acrylic acid) (PAA) initiated both by gamma irradiation and water soluble azo initiators was found to follow classical free radical kinetics. A significant increase in the rate of the propagation step (together with the degree of polymerization) was observed as the water fraction of the medium increased. During homogeneous polymerization of acrylic acid in methanol-water solutions containing poly(ethylene oxide), PAA grafting efficiency was found to be 67% and independent of initiation rate and yield. A mechanism of grafting to poly(ethylene oxide) was proposed. Chain transfer to PEO (K/sub tr/ = 6.5 x 10/sup -5/) was found to be the dominant mechanism for graft formation. Drag reduction characteristics of these PEO-PAA graft copolymers were measured in dilute aqueous solutions as a function of Reynolds number and solution pH. PEO graft copolymers containing 45% by mole PAA graft had, in neutral and basic solutions, drag reduction characteristics equivalent on a mass basis to the initial PEO. However at low pH, drag reduction characteristics disappeared as the PEO-PAA coacervate formed.
- Research Organization:
- Columbia Univ., New York (USA)
- OSTI ID:
- 6436466
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ACRYLIC ACID
POLYMERIZATION
EPOXIDES
COPOLYMERIZATION
CHEMICAL REACTION KINETICS
EXPERIMENTAL DATA
GAMMA RADIATION
RADIOLYSIS
CARBOXYLIC ACIDS
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
DATA
DECOMPOSITION
ELECTROMAGNETIC RADIATION
INFORMATION
IONIZING RADIATIONS
KINETICS
MONOCARBOXYLIC ACIDS
NUMERICAL DATA
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIATIONS
REACTION KINETICS
400600* - Radiation Chemistry