ISSN:
0887-624X
Schlagwort(e):
amic acid
;
secondary amine
;
maleic anhydride
;
melt reaction kinetics
;
model compounds
;
polymer-bound functional groups
;
Chemistry
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
This study examines the legitimacy of using the reaction kinetics of low molecular weight model compounds in solution to predict the chemical kinetics of polymer-bound species in a homogeneous melt. The reaction under study takes place between an aliphatic secondary amine, diisooctadecylamine (DiOA), and a 5-membered anhydride ring, saturated maleic anhydride (MA), forming an amic acid product. The MA species was present as a pendant graft on either a model compound, dodecane-g-(maleic anhydride) (dodecane-g-MA), or a polymer chain, linear low-density polyethylene-g-(maleic anhydride) (LLDPE-g-MA). Pseudo-second-order kinetics of the anhydride consumption are followed by infrared spectroscopy, either in situ in dodecane solution or by scanning frozen film samples taken from a linear low-density polyethylene melt. It was found that the LLDPE-g-MA/DiOA system reacted at a slightly slower rate than the dodecane-g-MA/DiOA system in the low-viscosity solution at 140°C. In the melt, the dodecane-g-MA/DiOA system experienced a small decrease in the overall reaction rate compared to the same reaction carried out in dodecane. However, the LLDPE-g-MA/DiOA system underwent a 65% decrease in the observed second-order rate constant on going from a solution to the melt. To explain these phenomena, the effects of diffusion, miscibility, and chain entanglements in the melt are examined here. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1573-1582, 1998
Zusätzliches Material:
3 Ill.
Materialart:
Digitale Medien
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