Abstract:
L'invention concerne un procédé de préparation d'un polymère modifié comprenant : - une étape de polymérisation anionique d'au moins un monomère diénique en présence d'un initiateur de polymérisation difonctionnel, pour obtenir un prépolymère vivant difonctionnel comprenant un site réactif à chacune de ses deux extrémités, puis - une étape de réaction dudit prépolymère vivant difonctionnel comprenant un site réactif à chacune de ses deux extrémités par polycondensation au moyen d'un agent de couplage difonctionnel de formule (I) suivante, où Y, Z désignent indépendamment une fonction réactive vis-à-vis du prépolymère vivant, R1 et R2 désignent indépendamment un groupe hydrocarboné, linéaire, ramifié ou cyclique,saturé ou insaturé,de préférence saturé, pouvant éventuellement contenir un ou plusieurs hétéroatomes, R1 et R2 étant exempts de site réactif vis-à-vis du prépolymère vivant, le rapport molaire r = n(prépolymère vivant difonctionnel)/n(agent de couplage) variant de 0,85 à 1,25.
Abstract:
The present disclosure provides a process for preparing a cured transparent rubber composition containing a synthetic isoprene polymer(s), a transparent polymer(s), a curing agent and additives. The process includes mixing the components at a temperature ranging from 50 to 130C, curing the compound with peroxide and allowing the compound to mature. The maturated compound is fed to an injection moulding machine. The cured transparent rubber composition prepared using the methods described herein has a haze of less than 30% and a total light transmission of more than 80%. The disclosure further provides an article including the cured transparent rubber composition, in particular for medical applications and artificial nipples.
Abstract:
Substituted phenacyl molecules are provided and employed to create molecules and polymers/copolymers that exhibit photoresponsiveness. In some instances, the substituted phenacyl molecule is incorporated into the polymer/copolymer backbone, and photoirradiation of the polymer/copolymer causes the substituted phenacyl group to break down and the polymer/copolymer to undergo degradation. In other instances, the substituted phenacyl molecules extend as a side chain from the polymer/copolymer backbone. In yet other instances the substituted phenacyl molecules extend as a side chain from the polymer/copolymer backbone, and a drug or polymer additive is linked to the photoresponsive substituted phenacyl group such that photoirradiation releases the drug or additive. In yet other embodiments the substituted phenacyl molecules extend as a side chain from the polymer/copolymer backbone, and serve to link the polymer/copolymer to another polymer/copolymer backbone, and photoirradiation breaks the links.
Abstract:
A method for preparing a functionalized polymer, the method comprising the steps of preparing a reactive polymer and reacting the reactive polymer with a heterocyclic nitrile compound.
Abstract:
Embodiments of the present invention are directed generally to methods for producing high purity exo-alkenylnorbornenes from a mixture of conformational isomers thereof.
Abstract:
A functionalized polymer includes a polymer chain and, bonded thereto, an functional group having the general formula -NHAR 1 where A is an oxygen atom, a sulfinyl (thionyl) group, a sulfonyl group, a quaternary phosphonium group, or a secondary amino group and where R 1 is a hydrogen atom or a moiety of the general formula -CH 2 Z where Z is H or a substituted or unsubstituted aryl, alkyl, alkenyl, alkenaryl, aralkenyl, alkaryl, or aralkyl group. The material can be the reaction product of a living polymer and a compound that includes protected imine functionality. The functional group can interact with particulate filler such as, e.g., carbon black.