| 摘要 |
A process of obtaining a thermoplastic composition formed from a polyolefin matrix is disclosed. The polyoelfin matrix comprises a polypropylene The process comprises (a) the formation of a viscoelastic mixture of the polypropylene and the lamellar mineral by heating and kneading the composition at a temperature at least equal to the working temperature of the polypropylene, (b) submitting the viscoelastic mixture to thermo-mechanical work, (c) eliminating volatile components from the viscoelastic mixture, and (d) transforming the viscoelastic mixture resulting from step (c) into a granulated material. The viscoelastic mixture is subjected during steps (a) and (b) to a weak and controlled rate of shearing of no more than 200 s−1 and the viscoelastic mixture is subjected in step (b) to at least one cycle of extension and relaxation in a dedicated zone which is at least 25% of the total length of at least one screw of a compounding extruder.
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