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Volumn 351, Issue 13, 2009, Pages 2168-2177

Silica-Supported zirconium complexes and their polyoligosilsesquioxane analogues in the transesterification of acrylates: Part 2. activity, recycling and regeneration

Author keywords

Acetylacetonate and alkoxy ligands exchange; Catalyst regeneration; Recycling; Silica supported zirconium complexes; Transesterification of (meth)acrylates

Indexed keywords


EID: 70349432314     PISSN: 16154150     EISSN: 15213897     Source Type: Journal    
DOI: 10.1002/adsc.200900274     Document Type: Article
Times cited : (22)

References (62)
  • 34
    • 70349412594 scopus 로고
    • Rohm and Haas Co. , US Patent 5,183,930
    • a) Rohm and Haas Co. , US Patent 5,183,930, 1993;
    • (1993)
  • 35
    • 70349434549 scopus 로고    scopus 로고
    • Rohm and Haas Co. , European Patent 0557131-Bl
    • b) Rohm and Haas Co. , European Patent 0557131-Bl, 1998.
    • (1998)
  • 48
    • 70349412593 scopus 로고    scopus 로고
    • Note
    • Many variations on protocol and analysis were explored in the pre-study. Final choices were based on a minimal condition of demonstrated reproducibility (less than 2% variance in yield at any point over three independent runs) with the objective of minimizing catalyst use and apparatus complexity. Among the factors studied were 1) comparison of batch results to protocols involving the continuous removal of the ethyl acrylate/ethanol azeotrope; 2) scale of the reaction between 8 mL and 100 mL scale; 3) the effect of the addition of molecular sieves (no effect) ; 4) the effect of added solvent (dodecane, no significant advantage); and 5) substrate to catalyst ratio (between 100 and 1000).
  • 49
    • 70349424416 scopus 로고    scopus 로고
    • Note
    • Neither polymerization nor Michael addition products were observed, perhaps due to the low temperature and the presence of a radical trap (hydroquinone stabilizer).
  • 50
    • 70349431818 scopus 로고    scopus 로고
    • Note
    • 4 is represented together with a discussion of its significance in the catalyst regeneration section (see Figure 7 and Figure 8).
  • 51
    • 70349424418 scopus 로고    scopus 로고
    • Note
    • Several different exploratory studies of lixivation were performed. These incomplete studies were all equivalent with the hypothesis that some lixivation was present during catalysis with the monopodal catalyst 1 but very little lixivation was observable for 2 and 3. For example, catalysts 1 and 2 (powders) were tested in the presence of silica beads. Zirconium microanalysis of the beads after reaction showed a similar degree of transfer of zirconium in the case of 1 (-20% transfer), but very little in the case of 2. In another study, catalyst 1 was continuously extracted (Soxhlet) with butanol for three days (the extraction bed temperature was not measured but was clearly superior to the 70°C catalytic test temperature): zirconium microanalysis of the solid showed loss of 28% of the initial zirconium.
  • 52
    • 70349423084 scopus 로고    scopus 로고
    • Note
    • Accurate quantification of the acetylacetonate would have required very careful study, given the relatively low concentration in the solution coupled with the ob- vious possibility of chemisorption and physisorption on the silica surface (which itself is undergoing modification during the reaction). The added value of this quantification was not deemed sufficient for the effort required.
  • 61
    • 70349433214 scopus 로고    scopus 로고
    • Atochem Elf SA, French Patent FR 2747675
    • a) Atochem Elf SA, French Patent FR 2747675, 1997;
    • (1997)
  • 62
    • 70349419175 scopus 로고    scopus 로고
    • Atochem Elf SA, French Patent FR 2747596, A note more fully describing this study is under preparation for publication
    • b) Atochem Elf SA, French Patent FR 2747596, 1997. A note more fully describing this study is under preparation for publication.
    • (1997)


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.