PROPENE POLYMERIZATION WITH MAGNESIUM CHLORIDE-SUPPORTED CATALYSTS: EFFECTS OF USING A DIETHER AS EXTERNAL DONOR
Chadwick, JC; Morini, G; Balbontin, G; Mingozzi, I; Albizzati, E
| HERO ID | 1313044 |
|---|---|
| In Press | No |
| Year | 1997 |
| Title | PROPENE POLYMERIZATION WITH MAGNESIUM CHLORIDE-SUPPORTED CATALYSTS: EFFECTS OF USING A DIETHER AS EXTERNAL DONOR |
| Authors | Chadwick, JC; Morini, G; Balbontin, G; Mingozzi, I; Albizzati, E |
| Journal | Macromolecular Chemistry and Physics |
| Abstract | Carbon-13 NMR analysis of PP fractions of differing tacticities, obtained using a catalyst system involving magnesium chloride /titanium tetrachloride/diisobutyl phthalate-triethylaluminium-diether, provided further evidence that the active species in this system were similar to those in which the ether was used as an 'internal' rather than 'external' donor. Chain-end analysis of relatively low molec.wt. polymer fractions indicated, for polymers of similar molec.wt., similar proportions of butyl-terminated chain-ends, indicative of chain transfer with hydrogen following regioirregular (2,1-) insertion. The relatively high hydrogen response of diether-containing catalyst systems could, therefore, be largely ascribed to this phenomenon, irrespective of whether the diether was used as internal or external donor. At relatively low hydrogen concentrations, chain transfer to hydrogen took place predominantly after the occasional secondary insertion, while the additional presence of vinylidene chain ends in certain xylene-soluble fractions indicated that chain transfer via beta-H transfer took place mainly after primary insertion. 17 refs. |
| Is Certified Translation | No |
| Dupe Override | No |
| Is Public | Yes |
| Keyword | POLYPROPYLENE; STEREOSPECIFIC POLYMERIZATION; SUPPORTED CATALYST; EXTERNAL DONOR; SOLUBLE; POLYALKENE; CONCENTRATION; THERMOPLASTIC; TABLES; PP; ITALY; GRAPH; POLYMERISATION MECHANISM; TACTICITY; PLASTIC; EUROPEAN UNION; END-GROUP ANALYSIS; EUROPEAN COMMUNITY; POLYPROPENE; SYNTHESIS; ACTIVE SPECIES; NMR; POLYOLEFIN; POLYMERISATION; ALKENE POLYMER; CATALYST; DATA; NETHERLANDS; MOLEC.WT.; STEREOREGULAR POLYMERISATION; TECHNICAL; OLEFIN POLYMER; ANALYSIS; NUCLEAR MAGNETIC RESONANCE; CHAIN TRANSFER; POLYMERIZATION MECHANISM; STEREOSPECIFIC POLYMERISATION; WESTERN EUROPE; MOLECULAR WEIGHT |