Search results for "Macromonomer"
showing 10 items of 32 documents
Amphipolar core-shell cylindrical brushes
1999
Methacryloyl-endfunctionalized block copolymers consisting of styrene and 2-vinylpyridine were polymerized to polyblockcomacromonomers with a much higher main chain than side chain degree of polymerization. Like homopolymacromonomers these molecules exhibit the structure of cylindrical brushes. Since the vinylpyridine block is coupled to the polymerizable group, the resulting cylindrical macromolecules exhibit a core of vinylpyridine and a shell of polystyrene, thus resembling an amphipolar unimolecular micelle of cylindrical shape. The micellar character of the structure is demonstrated by loading the cylindrical brushes with tetrachloroauric acid in toluene. Subsequent reduction leads to …
An All-ROMP Route to Graft Copolymers
2007
A new versatile synthesis strategy for macromonomers has been developed that uses the living ring-opening metathesis polymerization (ROMP) with commercial Grubbs first generation ruthenium initiators. Homopolymers as well as diblock copolymers were end-functionalized with norbornene derivatives to serve as macromonomers. The graft copolymerization of the macromonomers was also carried out employing ROMP. Well-defined and highly functional graft copolymers are accessible by this new synthetic route.
Amphipolar Core−Shell Cylindrical Brushes as Templates for the Formation of Gold Clusters and Nanowires
2002
Methacryloyl end-functionalized block copolymers consisting of styrene and vinyl-2-pyridine were polymerized to poly(block co-macromonomer)s with a much higher main chain than side chain degree of ...
Synthesis of a polystyrene-arm-polybutadiene-arm-poly(methyl methacrylate) triarm star copolymer
1996
The straightforward synthesis of a polystyrene-arm-polybutadiene-arm-poly(methyl methacrylate) triarm star copolymer has been successfully realized by a sequence of reactions which involves the sequential addition of a living polybutadienyllithium to a polystyrene macromonomer with a terminal 1,1-diphenylethylene unit and subsequent polymerization of methyl methacrylate. The high-molecular-weight polystyrene-arm-polybutadiene-arm-poly(methyl methacrylate) star copolymer shows microphase separation into three phases.
Synthesis and degradation of poly (2-hydroxyethyl methacrylate)-graft-poly (ε-caprolactone) copolymers
2004
Abstract Poly (e-caprolactone) macromonomers carrying a methacryloyl end groups were synthesized using different lanthanide derivatives as catalysts, and characterized by SEC and 1 H NMR. Hydrophilic–hydrophobic copolymers from macromonomers and 2-hydroxyethyl methacrylate (HEMA) were obtained by solution free radical polymerization. Depending on the feed ratio of the two components, different copolymer structures were obtained. The expected graft structure of the copolymers was confirmed by 1 H NMR. Thermal properties of the copolymers were determined by DSC and TGA. Hydrolytic and enzymatic degradations of the materials were performed. Poly (2-hydroxyethyl methacrylate)- graft -poly (e-ca…
Polyether Core-Shell Cylinder-Polymerization of Polyglycidol Macromonomers
2005
The synthesis and polymerization of macromonomers containing a polymerizable styrene head group and a tail of ethylene oxide derivatives of different character were investigated. The synthesis of macromonomers was based on living anionic polymerization of oxiranes. Two monomers were used: 1-ethoxyethyl glycidyl ether (glycidol acetal), which after hydrolysis forms hydrophilic glycidol blocks and glycidyl phenyl ether forming hydrophobic blocks. Polymerizable double bonds were introduced by terminating the living chain with p-(chloromethyl)styrene. The radical polymerization of the macromonomers was carried out in water with addition of a non-polar solvent (benzene) and AIBN as initiator. Co…
Some new polyelectrolytes
1989
Revue de methodes de preparation de polyelectrolytes: alkylation du poly(iminohexamethylene), homo- et copolymeres sequences de l'aza-1 bicyclo [4.2.0] octane, polymeres-peignes prepares a partir de macromeres obtenus par polymerisation de la phenyl-2 oxazoline. Preparation de polyampholytes ayant une distribution statistique ou sequencee des motifs ioniques
A continuous reaction system to investigate dispersion polymerization of vinyl monomers in supercritical carbon dioxide
2006
A laboratory-scale continuous reaction system using a stirred tank reac- tor was assembled in our laboratory to study the dispersion polymerization of vinyl monomers in supercritical carbon dioxide (scCO2). The apparatus was equipped with a suitable downstream separation section to collect solid particles entrained in the effluent stream from the reactor, whose monomer concentration could be measured online with a gas chromatograph. The dispersion polymerization of methyl methacry- late in scCO2 was selected as a model process to be investigated in the apparatus. The experiments were performed at 65 8C and 25 MPa with 2,2 0 -azobisisobutyroni- trile as the initiator and a reactive polysilox…
Synthesis of polycaprolactone by microwave irradiation ? an interesting route to synthesize this polymer via green chemistry
2003
Poly(e-caprolactone) has become an important biocompatible and biodegradable polymer. Indeed, due to its multiple biomedical applications, the synthesis of polycaprolactone has received increased attention in the past few decades. Moreover, microwave irradiation is a very clean modern technique widely used for green chemistry. Here, several polymers were synthesized by microwave irradiation, without any solvent, using nontoxic, biologically acceptable lanthanide halides as initiators. Reaction times varied between 2 and 90 min. The molecular weights of the obtained polymer products were between 3,000 and 16,000 g/mol. After polymerization, the polycaprolactone polymers were functionalized b…
An Easy Way Towardɛ-Caprolactone Macromonomers by Microwave Irradiation Using Early Lanthanide Halides as Catalysts
2002
Poly(e-caprolactone) macromonomers were synthesized under microwave irradiation from commercial caprolactone, using commercial hydrated lanthanide halides as catalysts. The molecular weight of the polymers was in the range 3 000–5 000. Higher molecular weights (5 000–20 000) and lower polydispersity indices were obtained with THF adducts of the lanthanide halides as catalysts and also by applying longer reaction times or using diethylene glycol as a coupling reagent.