Alder Ene functionalization of polypropylene through reactive extrusion
โ Scribed by Michael R. Thompson; Costas Tzoganakis; Garry L. Rempel
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 227 KB
- Volume
- 71
- Category
- Article
- ISSN
- 0021-8995
No coin nor oath required. For personal study only.
โฆ Synopsis
A commercial isotactic polypropylene was degraded to increase its terminal vinylidene group concentration, and it was subsequently functionalized with maleic anhydride through the Alder Ene reaction at temperatures above 200ยฐC in a co-rotating twin screw extruder. Characterization of the maleated product by Fourier transform infrared spectroscopy, 1 H NMR, differential scanning calorimetry, and gel permeation chromatography showed the anhydride group to be terminally attached, and the degree of functionalization was determined by infrared analysis. Increased temperature and maleic anhydride concentration, as well as improved mixing in the extruder, were found to improve the extent of the reaction. The catalytic contribution of Lewis acid species was evaluated, and ruthenium chloride was found to increase the extent of the reaction by 16% in comparison with stannous chloride as a catalyst in the Alder Ene reaction.
๐ SIMILAR VOLUMES
A kinetic model for the free-radical-initiated molecular weight degradation of polypropylene was further developed. The model has a single variable parameter, the initiator efficiency, f . Assumptions were detailed, new comparisons with experimental data presented, and model sensitivity to the value
Maleic anhydride (MAn) was grafted onto aliphatic and aromatic/aliphatic copolyesters by reactive extrusion in the presence of a free radical initiator using a twin-screw extruder. The grafting reaction was confirmed by spectroscopic analyses. The presence of succinic anhydride groups was shown by F
A study of the parameters that affect the Alder Ene reaction with respect to the synthesis of a terminally anhydride-functionalized polypropylene was carried out over a temperature range of 220 -250ยฐC using maleic anhydride concentrations of 2-12 mol equivalence with respect to the vinylidene group.