Abstract: The present invention describes a hydraulic cement composition, its obtaining process and its use. More precisely, the hydraulic cement composition comprises increased resistance to CO2 for application in subsurface fluid reservoirs.

Abstract: A fiber and a process for obtaining same from a high-modulus polyethylene, extrudable in state-of-the-art equipment and in the absence of previous solubilization in any kind of organic solvent is described, the process comprising providing such a polyethylene, introducing it in a state-of-the-art extruder, extruding it according to a temperature pattern, obtaining an extrudate that is directed to a cooling bath to have its temperature reduced, then directing the extrudate to a first stretcher where it is stretched or drawn into a fiber of improved tenacity, at a first velocity v1, then heating the fiber at nearly 90° C. and then directing said fiber to a second stretcher to be drawn at a final velocity v2, wherein v1<v2, at a draw ratio of 2/1 until 65/1. The tenacity of the polyethylene fiber obtained by the said process attains at least 4 gf/den, which makes it useful to naval and offshore applications.

Abstract: A fiber and a process for obtaining same from a high-modulus polyethylene, extrudable in state-of-the-art equipment and in the absence of previous solubilization in any kind of organic solvent is described, the process comprising providing such a polyethylene, introducing it in a state-of-the-art extruder, extruding it according to a temperature pattern, obtaining an extrudate that is directed to a cooling bath to have its temperature reduced, then directing the extrudate to a first stretcher where it is stretched or drawn into a fiber of improved tenacity, at a first velocity v1, then heating the fiber at nearly 90° C. and then directing said fiber to a second stretcher to be drawn at a final velocity v2, wherein v1<v2, at a draw ratio of 2/1 until 65/1. The tenacity of the polyethylene fiber obtained by the said process attains at least 4 gf/den, which makes it useful to naval and offshore applications.

Abstract: A fiber and a process for obtaining same from a high-modulus polyethylene, extrudable in state-of-the-art equipment and in the absence of previous solubilization in any kind of organic solvent is described, the process comprising providing such a polyethylene, introducing it in a state-of-the-art extruder, extruding it according to a temperature pattern, obtaining an extrudate that is directed to a cooling bath to have its temperature reduced, then directing the extrudate to a first stretcher where it is stretched or drawn into a fiber of improved tenacity, at a first velocity v1, then heating the fiber at nearly 90° C. and then directing said fiber to a second stretcher to be drawn at a final velocity v2, wherein v1<v2, at a draw ratio of 2/1 until 65/1. The tenacity of the polyethylene fiber obtained by the said process attains at least 4 gf/den, which makes it useful to naval and offshore applications.

Abstract: A preparation process for a catalytic support, based on a special alumina modified with varying quantities of magnesium chloride is described, a higher rate of MgCl.sub.2 leading to a lesser quantity of heavy molecular chains in the final polymer. The support, prepared by milling the special alumina together with the MgCl.sub.2 previously treated with ethyl benzoate, is impregnated with TiCl.sub.4 in order to create the catalyst. The resulting catalysts show high activity, which enables the metallic residue and chloride eliminating stage to be avoided in the resin so created. Furthermore the types of molecular weight distribution and of mechanical properties are different for the polymers produced.

Abstract: A preparation process for a catalytic support, based on a special alumina modified with varying quantities of magnesium chloride is described, a higher rate of MgCl.sub.2 leading to a lesser quantity of heavy molecular chains in the final polymer. The support, prepared by milling the special alumina together with the MgCl.sub.2 previously treated with ethyl benzoate, is impregnated with TiCl.sub.4 in order to create the catalyst. The resulting catalysts show high activity, which enables the metallic residue and chloride eliminating stage to be avoided in the resin so created. Furthermore the types of molecular weight distribution and of mechanical properties are different for the polymers produced.