Ethylene and butadiene are copolymerized with neodymocene catalysts. In this paper, a complete 1H and 13C NMR analysis of ethylene/butadiene copolymers is reported for the first time. The results of this study show that the microstructure of copolymers depends on the cyclopentadienyl ligands of the catalyst. The presence of the trans-1,2-cyclohexane structure, formed by intramolecular cyclization, is detected and fully investigated by 2D NMR 1H/13C direct and long-range correlation.

Novel P,O-chelated Ni(II) catalysts for ethylene and R-olefins polymerization have been used for the copolymerization of ethylene with various long-chain R-olefins in emulsion. Nonfunctionalized R-olefins have been copolymerized with ethylene using miniemulsion to disperse the catalyst at the nanometric level. The influence of the comonomer on catalyst performances as well as latex properties has been analyzed. High comonomer incorporation and stable latex of 30% solid content can be achieved by this method. Other comonomers such as R,ω-dienes, R-olefins bearing a polar functionality in the ω-position, and styrene have also been copolymerized in emulsion. Polymers and latexes have been characterized by an array of techniques including 13 C NMR, TEM, DSC, and GPC. It is shown that this emulsion process is specially adapted for copolymerization of ethylene with polar olefins.

The field of the copolymerization of olefins with conjugated dienes has been investigated. While the insertion of butadiene is often limited with most catalyst systems designed for olefin polymerization, lanthanide metallocene catalysts insert butadiene with good efficiency. In the present paper, the preparation of a vast range of products including new polymers is reviewed.

Functionalized poly(ecapro1actone)s have been easily prepared by using a new heterogeneous catalytic system consisting of aluminium alcoholate supported on porous silica and the corresponding alcohol in excess. The polymers have been fully characterized by 'H and I3C NMR spectroscopy. Oligo(capro1actone-co-ethylene oxide)s have been synthesized by the same catalytic system. The diad comonomer distribution as obtained by 'H NMR suggests a blocky structure. In addition, low degrees of crystallization have been determined by means of DSC.

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This article deals with a new way of improving the melt viscosity of linear poly(ethylene terephthalate) (PET) chains through the reaction of the PET end groups (alcohol and acid) with new chain extenders, 3-(triethoxysilyl)propylsuccinic anhydride (ASSI) and 3-glycidoxypropyltrimethoxysilane, during the melt processing of PET. The reactions, investigated with model compounds monomethylterephthalate and triethylene glycol monomethylether for PETOCOOH and OOH end groups, respectively, by multinuclear NMR spectroscopy ( 1 H, 13 C, and 29 Si), provided evidence of well-known acid-epoxide and alcohol-anhydride reactions, respectively. In addition, numerous other species appeared because of the presence of alkoxysilane groups, such as alcoholalkoxysilane exchange reactions, acyloxysilane formation, and hydrolysis-condensation reactions of alkoxysilane. All these reactions led to the formation of branched chains when transposed to PET melt modification. A size exclusion chromatography analysis and the rheological behavior confirmed the presence of branched structures embedded in shorter linear PET chains. The rheological behavior of this blend was drastically modified in comparison with that of neat PET; consequently, there was an important increase in the zero-shear viscosity, with a maximum concentration of branched structures of about 17 vol % obtained with an ASSI/PET molar ratio of 4.

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Cationic and zwitterionic reactive dialkyl maleates with different hydrophobic chain lengths (R ) C10H21, C12H25, C16H33, and C18H37), and some similar surfactants without double bonds were synthesized with an aim to use them as stabilizers in the batch and seeded emulsion copolymerization of styrene and butyl acrylate (part 2 of this series). Surfactants are obtained in a three-step synthesis, starting from ring opening of maleic anhydride, followed by O alkylation with an aminoalkyl compound, and finishing with quaternization of the amino group in the hydrophilic part of the molecule. The chemical structure of surfactants was confirmed by 1 H NMR. Melting points and critical micelle concentrations of the synthesized surfactants were measured. The specific area per molecule at the air/water interface was calculated for most of the surfactants. The adsorption of the surfactant on the polystyrene (PS) and PS/poly(butyl acrylate) copolymer was also measured, and the specific area occupied by the surfactant molecule was calculated in one example.