摘要:
The present invention generally relates to the field of conformance control in oil fields, particularly to a re-crosslinkable preformed particle gel system, and composition thereof. The composition of the re-crosslinkable preformed particle gel system contains monomers, crosslinkers, a polymer matrix, and additives. Components in the composition for re- crosslinkable preformed particle gel in the present invention have excellent compatibility with each other, and the obtained gel has excellent long term high-temperature resistance property. Different from prior products, in the re-crosslinkable preformed particle gel compositions according to embodiments of the present invention, the components that are used to re-crosslink the particle gels may be grafted on the polymer chain and will act as initiator or secondary crosslinker in different conditions. During particle injection process, all compositions would move together, thereby avoiding chromatographic problems typical of prior products.
摘要:
Polymerizable compositions comprising a redox initiator system is disclosed. The redox initiator system comprises a photolabile transition metal complex that photolyzes and initiates the redox cycle. Dental compositions comprising dental resins and the photolabile redox initiator system are also described.
摘要:
A vinyl monomer of the structure R-B-Ar(-CH=CH2)n (1) in which Ar is an aromatic ring (arylene group); n is an integer > 0, in particular one or two; B is a bridge structure; R is a (C2-30)-hydrocarbon group carrying two or more protected or unprotected hydroxy groups. The monomer is characterized in that B comprises a chain of atoms linking R to Ar and consisting of 1-10 atoms selected from carbons and the heteroatoms ether oxygen, thioether sulphur or amino nitrogen, with the proviso that the terminal atom in B which is attached to R is one of the heteroatoms. A method for producing a polymer support matrix in which the vinylmonomer is one of the monomeric units. The support matrix as such is also claimed. The preferred method for producing the support matrices involves suspension polymerisation, the preferred form of matrix is beads. The matrix is cross-linked.
摘要:
The invention relates to a retarder composition for the control of unwanted polymerisation reactions during the production and processing of ethylenically unsaturated compounds, the composition comprising at least one di-substituted quinone compound and at least one hydroxylamine compound. Optionally, the composition also comprises at least one stable free radical nitroxyl compound and one or more formulation adjuvants. The invention also envisages a process stream comprising at least one ethylenically unsaturated compound, and a method for the prevention of unwanted polymerisation reactions during the production and processing of ethylenically unsaturated compounds. The composition has been found to be far more effective than expected, given that the individual components show little or no efficacy when used alone, and poses much less hazard to humans than the compositions of the prior art.