Preparation method and use of hybrid composite pipes

A hybrid composite pipe, comprising:

• an outer layer;
• an inner layer;
• and
• a main structural layer;
• wherein the main structural layer is arranged between the inner layer and the outer layer;
• the outer layer and the inner layer are made from a first polymer or a metal base pipe;
• the main structural layer comprises a first hybrid structural layer, a base pipe and a second hybrid structural layer;
• the first hybrid structural layer is arranged between the inner layer and the base pipe, and the second hybrid structural layer is arranged between the base pipe and the outer layer;
• the first hybrid structural layer and the second hybrid structural layer each consist of a second polymer as a matrix with porous aggregates or granules that are modified with a surfactant, a coupling agent or a cross-linking agent;
• the porous aggregates or granules have a bulk density of less than 1200 kg/m3, a particle size less than or equal to 15 mm, and a cylinder pressure greater than or equal to 8 MPa;
• wherein the porous aggregates or granules have pores on their surfaces;
• gas is blocked within the pores on the surfaces of the porous aggregates or granules by the second polymer the first polymer and the second polymer comprise thermosetting polymers and thermoplastic polymers;
• and at least one of the base pipe and the outer layer is a galvanized corrugated steel pipe.