Radical polymerization of N-vinylpyrrolidone in the presence of syndiotactic poly(methacrylic acid) templates. [Gamma ray]

Journal Article · Sun Jun 01 04:00:00 EDT 1980 · J. Polym. Sci., Polym. Chem. Ed.; (United States)

DOI:https://doi.org/10.1002/pol.1980.170180629· OSTI ID:5101923

Koetsier, D W; Tan, Y Y; Challa, G

Radical polymerization of N-vinylpyrrolidone along poly(methacrylic acid) templates of high syndiotactic content was followed dilatometrically in dimethylformamide, which was used as solvent. The effects of template concentration, template molar mass, and temperature on polymerization rate and average molar mass of the formed polyvinylpyrrolidone (PVP) were examined. Template concentrations were varied around the critical concentration for homogeneous segmental distribution, C. Below this concentration, template coils can act as separate microreactors wherein growing PVP radicals exhibit maximum rate enhancement, i.e., relative rate upsilon/sub R/ = upsilon/sub R max/. In the free solution, blank polymerization occurs, i.e., upsilon/sub R/ = 1. Consequently, upsilon/sub R/ can be approximated by the equation ..nu../sub R/ = phi..nu../sub R/max/ + (1 - phi), where phi represents the volume fraction occupied by template coils. The slight increase in ..nu../sub R/ and PVP molar mass with the template chain length is supposed to be caused by the influence of translational diffusion on the termination step. Over the investigated temperature range of 50 to 70/sup 0/C, the activation energy and entropy were almost identical for blank and template polymerization. An expected decrease of ..delta..E not equal to and ..delta..S not equal to in template systems is supposed to be compensated by the effects of desolvation of the template macromolecules during the propagation step.

• Research Organization: State Univ. of Groningen, Netherlands
• OSTI ID: 5101923
• Journal Information: J. Polym. Sci., Polym. Chem. Ed.; (United States), Journal Name: J. Polym. Sci., Polym. Chem. Ed.; (United States) Vol. 18:6; ISSN JPLCA
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400600* -- Radiation Chemistry
ACTIVATION ENERGY
AMIDES
AZOLES
CARBOXYLIC ACIDS
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
COMPARATIVE EVALUATIONS
DILATOMETRY
ELECTROMAGNETIC RADIATION
ENERGY
ENTROPY
ESTERS
GAMMA RADIATION
HETEROCYCLIC COMPOUNDS
IONIZING RADIATIONS
LACTAMS
MEDIUM TEMPERATURE
METHACRYLIC ACID
MONOCARBOXYLIC ACIDS
MONOMERS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC POLYMERS
PHYSICAL PROPERTIES
PMMA
POLYACRYLATES
POLYMERIZATION
POLYMERS
POLYVINYLS
PYRROLES
PYRROLIDONES
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIATIONS
THERMAL ANALYSIS
THERMODYNAMIC PROPERTIES
VINYL MONOMERS