Search results for "Polymers"

Darstellung und charakterisierung von einigen neuen bis(1-phenylvinyl)-verbindungen

1974

Einige neue Bis(1-phenylvinyl)-Verbindungen (1b, c und 2a–d) wurden aus den entsprechenden Diacetylverbindungen und Phenylmagnesiumbromid dargestellt. Ihre IR-, NMR-und Massenspektren werden diskutiert. Some new bis(1-phenylvinyl) compounds (1b, c and 2a–d) were prepared from the corresponding diacetyl compounds and phenyl magnesium bromide. Their IR, NMR and mass spectra are discussed.

Block copolymers in giant unilamellar vesicles with proteins or with phospholipids

2013

Biocompatible, highly water-soluble, nonionic, amphiphilic block copolymers having different hydrophobic blocks and architectures, but similar molecular size and chemical nature of the hydrophilic blocks, were investigated to check for their ability to form hybrid giant unilamellar vesicles with proteins, and for their interactions with giant unilamellar phospholipid vesicles (GUV). PGM14-b-PPO34-b-PGM14 (PGM-PPO-PGM) consists of a poly(propylene oxide) middle block and outer poly(glycerol monomethacrylate) blocks. Ch-PEG32-b-lPG18 (Ch-PEG-lPG) and Ch-PEG30-b-hbPG17 (Ch-PEG-hbPG) have a linear poly(ethylene glycol) block, linked to a cholesterol end group and to a linear (lPG) or hyperbranc…

Polymerization of ethylene in the presence of organometallic complexes formed by chloroisopropoxytitanium compounds and sesquiethylchloroaluminium

1982

The catalytic activity of organometallic complexes obtained from chloroisopropoxytitanium compounds and sesquiethylchloroaluminium has been studied. The complexes are active as catalysts for polymerization of ethylene, living high molecular weight product with high output. It is found that the molar ratio of catalyst components affects the output and molecular weight of polyethylene. The optimum molar ratiofor three catalytic systems is given.

Preparation and Recycling of Plasticized PLA

2010

Poly(lacticacid)(PLA)hasbeengainingarisinginterestoverthe last years as a biodegradable and environmental-friendly substitute of traditional non-biodegradable poly-mers.Several ways exist to synthesize PLA, however, poly-merization through lactide formation is the most used onindustrial scale, allowing to obtain optimum results interms of mechanical and thermal properties.

Influence of long chain branching on the elongational behaviour of different polyethylenes and their blends

1986

Elongational data on a series of polyethylenes with different structure and on their blends are presented in order to correlate the extensional behaviour with the long chain branching degree.

Hemiesters and hemiamides of maleic and succinic acid: synthesis and application of surfactants in emulsion polymerization with styrene and butyl acr…

1999

Hemiesters and hemiamides of maleic acid with different chain lengths of the hydrophobic alkyl group (R = C8H17, C10H21, C12H25, C16H33) have been synthesized and used as surfactants in the emulsion polymerization of styrene and butyl acrylate. The same polymerization experiments were also carried out using nonreactive surfactants with an analogous succinic structure. The chemical structure of the surfactants was confirmed by 1H nuclear magnetic resonance. The melting point and critical micelle concentration of the reactive surfactants described herein were measured. All of the surfactants studied provided good stability of styrene/butyl acrylate latexes, when compared with a reference late…

Recycling of heterogeneous plastics wastes. II—The role of modifier agents

1993

Abstract Recycling of mixed plastics waste, mainly composed of PEs, PET and PVC has been carried out by blending with recycled polyethylene. Although the extrusion of these blends has been carried out at high temperatures, the degradation of the PVC was modest due to the short residence times. The mechanical properties of these secondary materials, up to about 30% of mixed plastics waste, are very similar to those of the recycled polyethylene, except for the elongation to break. By adding some modifier agents, the elongation at break and especially the impact strength can be further improved.

Methacrylic maleic bifunctional stabilizer in emulsion polymerization

1998

Photoinduced Charge Separation of Self-Organized Semiconducting Superstructures Composed of a Functional Polymer-TiO2 Hybrid

2013

Morphological Characterisation of Bacterial Cellulose-Starch Nanocomposites

2008

Acetobacter sp. growing medium was modified in order to produce bacterial cellulose (BC) nanocomposites using a bottom-up technique that allowed starch to be introduced into the cellulose network. The BC-starch mats were hot-pressed to obtain nanocomposites sheets. Morphological characterisation was carried out using Atomic Force Microscopy and Environmental Scanning Electron Microscopy. The images obtained from microscopy were then processed using image analysis. Network properties, such as mesh size and fibre orientation were characterised. Fracture surfaces of these new nanocomposites were analysed.