摘要:
The invention relates to a novel polymerization method for (meth)acrylates, wherein the polymerization is initiated by isocyanates and special bases having an imine structure. By means of said novel method that can be deliberately employed, even high-molecular-weight poly(meth)acrylates having in part a narrow molecular weight distribution can be produced. Furthermore, a wide variety of polymer architectures, such as block, star or comb polymers, are available using said novel polymerization method.
摘要:
Dental materials based on polymerizable binders, which contain at least one chromophoric xerogel of the formula I: (SiO2)a(SiO1.5-Sp-X-CG)(MenOm)b (I) in which Me represents a main-group metal of the 2nd to 3rd main groups or a transition metal of the 4th sub-group of the periodic table of elements; n being equal to 1 or 2, m being equal to 1 or 2 if n is equal to 1 and m being equal to 3 if n is equal to 2; Sp is a C1 to C10 alkylene radical or C2 to C10 oxyalkylene radical with 1 to 4 oxygen atoms or is absent; X is a compound group, such as CO—O, O—CO, CO—NH, NH—CO, O—CO—NH, NH—CO—O, NR, O or S or is absent, R being hydrogen or a C1 to C5 alkyl radical; CG is a chromophore; a is an integer from 0 to 20 and b is an integer from 0 to 5.
摘要:
The present invention relates to a novel type of grafting or crosslinking method for (meth)acrylates in which the reaction is initiated by isocyanates and specific bases having an imine structure. Using this novel and specifically applicable method, polymers, particularly polyolefins having double bonds, may be grafted or crosslinked in a suitable reaction procedure.Furthermore, these unsaturated polymers may be used, following reaction with (poly)isocyanates, to prepare graft or block copolymers or also for the bonding of the modified unsaturated polyolefins to polyamides, polyesters, polycarbonates, polyimines or polyurethanes.
摘要:
The invention describes novel polymer-functionalized carbon nanotubes. These comprise a carbon nanotube, a first polymer that is adsorbed on the outer surface of a carbon nanotube and comprises amino groups, and a second polymer covalently bonded to the first polymer. The bond between the second polymer and the first polymer is formed by the reaction of amino groups from the first polymer with groups from the second polymer that are reactive with respect to amino groups. The invention further relates to a method for the production thereof, wherein carbon nanotubes are provided in an aqueous solution of a first polymer comprising amino groups and then a solution of a second polymer comprising groups that are reactive with respect to amino groups is added. The invention also relates to the use of the carbon nanotubes in dispersions, polymers and surface coatings.
摘要:
The invention relates to monolithic materials which consist of porous, preferably highly porous, carbon and are suitable, inter alia, for the storage of gases, such as, for example, hydrogen and methane, and for absorptive and adsorptive gas purification.
摘要:
The present invention relates to an innovative polymerization technique for (meth)acrylates or styrenes, in which a special base with imine structure is added as a latent initiator, and the polymerization can be initiated without adding a coinitiator, at high temperatures. With this new and selectively employable technique it is also possible to produce high molecular weight poly(meth)acrylates having in some cases narrow molecular weight distribution. Furthermore, employing this new polymerization technique, a wide variety of different polymer architectures is available, such as block, star, or comb polymers.
摘要:
The present invention provides a polymer laminar composite including a first layer and a second layer at least partially in contact with the first layer. The first layer includes a polyurethane polymer which is the reaction product of a polyisocyanate A) and/or a polyisocyanate prepolymer B) with an at least difunctional, isocyanate-group-reactive compound C) and a monomeric, monofunctional aromatic alcohol. The second layer includes polymeric thiophene of the formula (I), substituted at the 3 and/or 4 position: and polystyrene sulfonate. 2-Hydroxymethyl-3,4-ethylene dioxythiophene is preferably used for the first layer and poly(3,4-ethylene dioxythiophene) for the second layer. The invention further relates to a process for producing such a laminar composite, as well as an electromechanical converter containing this laminar composite.