Homo- and Copolymerizations of Ethylene and Norbornene Using Bis(β-ketoamino) Titanium Catalysts Containing Pyrazolone Rings
A series of bis(β-ketoamino) titanium complexes containing pyrazolone rings (1–3) have been synthesized, characterized, and used as precursors for homo- and copolymerization of ethylene and norbornene. The titanium complexes activated with methylaluminoxane (MAO) exhibited good activities for homopolymerization of ethylene (E) to produce linear polyethylenes (PEs). Ethylene–norbornene copolymers (E–N) were also prepared by these catalysts with moderate activities, and influences of ligand substituents and norbornene addition on copolymer microstructure were studied in detail. Microstructure analysis of the E–N copolymers by 13C NMR and differential scanning calorimetry (DSC) techniques showed that alternating (ENEN) and isolated (ENEE) norbornene predominately appeared in the copolymer chain, and the NN dyad and NNN triad sequences were also present in the copolymers obtained by the less bulky catalyst 1.
Copolymerization of Norbornene and Styrene Catalyzed by a Series of Bis(β-ketoamine) Nickel(II) Complexes in the Presence of Methylaluminoxane
SummaryRandom copolymerization of norbornene with styrene was studied by using a series of late metal catalysts/MAO. The precatalysts used here are nickel complexes with b-ketoamine ligands based on pyrazolone derivatives. The copolymers obtained here suggest that only one type of active species is present. Copolymers were characterized by 13C NMR, Gel permeation chromatography (GPC), thermogravimetric analysis (TGA) and FT-IR spectra. The analyses of the product by 1H NMR and 13C NMR spectra gave the verification of “true” random vinyl addition copolymer. Varying the monomer feed ratio controlled the composition of the copolymers. A copolymerization reactivity ratio (rNBE = 20.35 and rSty = 0.027) indicates a much higher reactivity of norbornene, which suggests a coordination polymerization mechanism. The solubility and processability of the copolymers are improved relative to polynorbornene and the thermostability of the copolymers is improved relative to polystyrene.
Neurology, psychology, and extraordinary religious experiences
Temporal lobe epilepsy and certain personality disorders often result in experiences described as “religious.” TLE research suggests a possible neurological basis for such experiences. Immediately the question arises about the authenticity of these experiences as religious. An experience is authentic if it furthers the authentic growth of the subject, regardless of what triggered it. So pathology may occasion authentic religious experiences, even as history exemplifies. For practical purposes, the further question about God in religious experience is secondary. The exception, miraculous occurrences, should not be granted without sufficient reason. This approach dissolves all conflict between science and faith.