خط مشی دسترسیدرباره ماپشتیبانی آنلاین
ثبت نامثبت نام
راهنماراهنما
فارسی
ورودورود
صفحه اصلیصفحه اصلی
جستجوی مدارک
تمام متن
منابع دیجیتالی
رکورد قبلیرکورد بعدی
Document Type:Latin Dissertation
Language of Document:English
Record Number:55190
Doc. No:TL25144
Call number:‭3242245‬
Main Entry:Jimoh Tijani
Title & Author:Catalytic hydroformylation of alkenes and polyalkenes: Novel approaches to catalyst synthesis, characterization and recyclingJimoh Tijani
College:King Fahd University of Petroleum and Minerals (Saudi Arabia)
Date:2006
Degree:Ph.D.
student score:2006
Page No:232
Abstract:Hydroformylation of olefins is a versatile method and well-established industrial process for the production of aldehydes using transition metal complexes as homogeneous catalysts. Currently, worldwide production of aldehydes exceeded seven million tons/year. Rhodium (I) complexes are the most active and selective catalysts for hydroformylation reaction. For any industrial application of homogeneously catalyzed reaction, a complete recycling of the generally expensive catalyst should be guaranteed. A thermomorphic system is characterized by solvent pairs that reversibly changes from biphasic to monophasic and vice versa as a function of temperature. We have applied the thermomorphic approach to rhodium-catalyzed hydroformylation of higher olefins (C>6). The effect of CO/H2 pressure, ligand/catalyst ratio on activity, selectivity and recycling were studied on 1-octene and other olefins. The impregnation of HRhCO(PPh3)3 on mesoporous materials such as MCM-41, through Phosphotungstic acid (PTA) gives a novel hydroformylation catalyst, which was characterized by XRD, IR, and 31p CP MAS NMR. The activity, selectivity and recycling of this supported catalyst were established by hydroformylation of 1-octene. The catalyst activity was shown by the recycling capability for several times without significant loss of activity. Results are presented on a novel application of catalysis to chemical modification of commercially available polybutadiene polymers. The functionalized polyaldehyde products are key intermediates in the development of various polymer derivatives which form the basis for various novel material and component applications, such as manufacture of automobile body components by reaction injection molding processing. Characterization of the reaction products using 13C and 1H NMR shows that the olefin units in the polybutadiene are selectively hydroformylated to the 1,2-terminal branched and 1,4-internal branched aldehydes products.
Subject:Pure sciences; Alkenes; Catalyst; Hydroformylation; Polyalkenes; Recycling; Chemistry; Organic chemistry; 0490:Organic chemistry; 0488:Chemistry
Added Entry:King Fahd University of Petroleum and Minerals (Saudi Arabia)