Abstract:
A variety of graft copolymers can be formed sodium poly (aspartate) with a wide variety of monomers in an aqueous medium by the use of grafting method in the presence of radical initiator at a temperature of from about five degrees Centigrade to about 100 degrees Centigrade. Graft copolymers at high conversion with molecular weight up to millions can be prepared using this method.
Abstract:
A process and apparatus for the (co) polymerization of styrene. The process is carried out by employing a liquid polymerization reaction mixture that includes styrene, in a mechanically stirred reactor in the form of a vessel comprising a side wall having the shape of a cylinder of revolution with a vertical axis (A), a bottom head and a top head that are joined to the side wall, the vessel being provided with a mechanical stirring device comprising (i) a central shaft of vertical axis coincident with the axis (A), connected to a drive system comprising a motor for rotating the central shaft, (ii) at least one baffle attached to the vessel, which process is characterized in that the baffle is away from the side wall of the vessel and takes the form of a cylinder of vertical axis and of rhomboidal cross section.
Abstract:
There are provided a modified natural rubber made from a modified natural rubber latex, in which a polar group-containing monomer is graft-polymerized to natural rubber latex, and a rubber composition comprising such a modified natural rubber and carbon black and/or silica. Also, there are provided a modified natural rubber latex in which a tin-containing monomer or an alkoxysilyl group-containing monomer is graft-polymerized to natural rubber latex and a modified natural rubber made therefrom and a rubber composition comprising such a modified natural rubber.
Abstract:
The present invention provides heterocyclic vinylic compounds that can be used to form biocidal polymers. The polymers thus generated can used alone or can be grafted onto textiles, fabrics and polymers. The polymers are readily converted to N-halamine structures on exposure to a halogen source such as commercially available chlorine bleach. The N-halamine derivatives exhibit potent antibacterial properties against microorganisms and these properties are durable and regenerable.
Abstract:
Modification of polymers of the type including carbon/carbon double bonds is disclosed wherein the polymerisation of at least one monomer of low water solubility within a pre-existing polymer latex yields material containing interlinked polymers. The process includes the steps of (a) taking or making a colloidal dispersion of the polymer in an aqueous medium, (b) swelling the polymer in the colloidal particles with at least one polymerisable monomer having a solubility in water of less than 10 molar; and (c) inducing a free-radical polymerisation of the monomer(s) within the swollen colloidal particles of the polymer. The process is particularly appropriate to preparation of modified natural rubber latex.
Abstract:
A process for producing natural rubber-based acrylonitrile butadiene styrene (ABS) powder. The process comprises introducing a portion of natural rubber, mixing divinylbenzene (DVB) with the portion of natural rubber to produce vulcanized natural rubber, mixing the vulcanized natural rubber with a monomer solution to produce grafted natural rubber, mixing a plurality of grafted polybutadiene rubbers with the grafted natural rubber to produce a latex masterbatch and mixing a coagulant to a portion of the latex masterbatch to produce natural rubber-based ABS powder. By mixing the DVB with the portion of natural rubber, an intermediate step which is required in conventional methods before the polymerization process, can be eliminated. A natural rubber-based acrylonitrile butadiene styrene (ABS) powder produced by the process is also disclosed.
Abstract:
The present invention pertains to a water-redispersible polymer powder based on at least one modified natural latex. The modified natural latex can be obtained by mixing natural latex with at least one radical initiator and/or oxidising agent, by mixing and reacting natural latex with at least one olefinically unsaturated monomer and with at least one radical initiator, and/or by mixing natural latex with at least one filler. Preferably, the polymer powder contains up to about 95 wt.% of least one natural latex, about 0 to 50 wt.% of at least one protective colloid, about 2 to 70 wt.% of at least one filler and/or anti-caking agent, as well as optionally further additives. In addition, the invention pertains to a process for the preparation of the polymer powder, the use thereof as an additive in building material compositions, as well as building material compositions containing the polymer powder.
Abstract:
Tire comprising at least one structural element including a crosslinked elastomeric material obtained by crosslinking a crosslinkable elastomeric composition comprising a crosslinkable elastomeric base comprising at least 30 phr, preferably of from 50 phr to 100 phr, of at least one elastomeric polymer grafted with at least one phenolic resin. Preferably, said structural element is a tire tread band.