摘要:
The reaction cycle time for the copolymerisation of unsaturated esters such as alkyl fumarates and vinyl acetate, and for the polymerisation of methacrylates and acrylates may be dramatically reduced by carrying out the polymerisation at elevated temperatures and pressures. An additional feature is the addition of initiator during polymerisation which leads to improved products especially for lubricating oil pour depressants and fuel and crude oil flow improvers.
摘要:
An improved method for providing acrylic copolymer resins is provided in which the polymerization solvent comprises a blend of methyl isobutyl ketone and alkyl-substituted benzenes. The monomers comprise hydroxy-substituted alkyl (meth)acrylate monomers and non-hydroxy substituted alkyl (meth)acrylate monomers, and the process provides an improved method for forming low molecular weight acrylic resins useful as components in acrylic coatings. The polymerization solvent can remain in the resin to become a solvent employed in the higher solids coating containing the thus-formed acrylic resins and provides improved electrical resistivity, improved solvency and decreased surface tensions over prior art polymerization solvents.
摘要:
Verfahren zur radikalischen Polymerisation von Acrylund Methacrylsäure, deren Estern und Amiden, Acrylnitril und Styrol, unter Verwendung eines flüssigen Mediums, das eine Schmelze von bei Raumtemperatur festen organischen Ver bindungen, vorzugsweise gesättigten oder ungesättigten, geradkettigen oder verzweigten Fettsäuren mit bis zu 30 (8 bis 26) C-Atomen beziehungsweise deren Derivaten (Ester, Amide, Fettalkohole) mit Tropfpunkten zwischen 25 und 120 (40 bis 110)° C ist. Das Gewichtsverhältnis von Monomeren zu den festen organischen Verbindungen soll 10 bis 90 : 90 bis 10 (25 bis75 : 75 bis 25) betragen. Das Verfahren erlaubt die direkte Herstellung von Kunst stoffadditiven für die Kunststoffverarbeitung, speziell für die Verarbeitung von elasomeren, thermoplastischen Polymeri saten und Duroplasten, insbesondere durch Warmverfor mung dar.
摘要:
A method forming shaped hydrogel articles such as soft contact lenses wherein hydrophilic monomers are mixed with an inert diluent prior to polymerization, and the diluent is replaced with water following the polymerization. Diluents yielding optically clear hydrogels with good mechanical properties are selected on the basis of their viscosity and their Hanson cohesion parameters relative to the cohesion parameters of the polymeric component of the hydrogel.
摘要:
Acrylic copolymer resins are provided which are formed by co-polymerization of a monomer mixture comprising hydroxy-substituted alkyl (meth)acrylates, alkyl methacrylates or vinyl aromatics, and higher alpha-olefins. The low molecular weight acrylic resins are especially useful as components in high solids acrylic coatings suitable for electrostatic spraying.
摘要:
Ethylenically unsaturated monomers are grafted on homo- and olefinic co-polymers by means of a radicalic reaction, operating at between 60°C and 160°C, in a solution of the polymer in a solving medium consisting of, or predominantly comprising a mixture of a component (A), chosen between aliphatic hydrocarbons, aromatic hydrocarbons, esters and ethers containing at least one aromatic or cycloaliphatic group, with a component (B) consisting of an aliphatic, cycloaliphatic or aromatic ketone, and by separating at the end of the reaction the grafted polymer, by means of the cooling down of the solution to a temperature below 40°C.
摘要:
Aromatic solvent-soluble linear oligomers or homopolymers of meta- or para-isopropenyl-a,a-dimethylbenzyl- isocyanate characterized by high isocyanate content are disclosed. Such oligomers or homopolymers are made by catalytic solution polymerization of the monomer in methylene chloride and/or toluene solution at a temperature of from about -80°C to about -25°C, followed by low- temperature neutralization of the polymerization catalyst.
摘要:
It has been unexpectedly found that meta-diisopropenyl benzene can be polymerized into poly-m-diisopropenyl benzene with a relatively narrow molecular weight distribution and with only a small degree of crosslinking (gel formation) if done in the presence of at least one alpha-olefin containing from 2 to 12 carbon atoms in tetrahydrofuran (solvent) at low temperatures employing an alkyl lithium initiator. The poly-m-diisopropenyl benzene produced by employing this technique has an isopropenyl moiety on almost every diisopropenyl benzene repeat unit in the polymer. This polymer is particularly useful since its pendant isopropenyl groups can be further reacted with other compounds leading to polymers with various functionalities. This technique can also be employed in the synthesis of copolymers containing repeat units derived from meta-diisopropenyl benzene and one or more other monomers. The copolymers synthesized using the process of this invention contain an essentially quantitative number of unreacted isopropenyl groups on the meta-diisopropenyl benzene repeat units in the polymer chain.
摘要:
An improved process for continuously producing ethylene-vinyl acetate copolymer containing 20 to 50 mol% of ethylene is provided. The process of this invention permits the stable production of the copolymer over a long period of time.