Robert P Roden

US Patent:

20190091915, Mar 28, 2019

Filed:

Oct 12, 2016

Appl. No.:

15/767742

Inventors:

- Karnataka, IN
Robert Roden - Union Town OH, US
Sambhu Bhadra - Karnataka, IN

International Classification:

C08F 220/06
B29C 35/08
B29K 33/00

Abstract:

A process for preparing hydrogels is disclosed. Said process comprises passing reactants comprising a monomer, an initiator and a cross-linker through a co-rotating twin screw extruder, the co-rotating twin screw extruder being operated at a screw speed of at least 200 rpm and comprising an inlet zone, an outlet zone, and in between the inlet zone and the outlet zone at least one mixing zone, at least one conveying zone and at least one back-mixing zone, wherein the back-mixing zone comprises of restricting elements which restrict the reactants from moving forward in the co-rotating twin screw extruder until a forward force sufficient to overcome the restriction is achieved, such that the co-rotating twin screw extruder provides sufficient shear energy and residence time to the reactants to (co)polymerize and produce hydrogel having a water uptake greater than 100 g/g.