High performance geosynthetic article

A process for forming a geotechnical article comprising at least one layer, said at least one layer having:

• a coefficient of thermal expansion less than about 150 ppm/° C. at ambient temperature;
• resistance to acidic media greater than polyamide 6 resin and/or resistance to basic media greater than PET resin;
• resistance to hydrocarbons greater than that of HDPE;
• creep modulus of at least 400 MPa at 25° C., at a load of 20% of yield stress and loading time of 60 minutes, according to ISO 899-1;
• and
• percent secant flexural modulus of at least 700 MPa, at 25° C. according to ASTM D790;
• said at least one layer formed of a composition comprising:
• (a) from about 1 to about 94.5% by weight of the composition of at least one functional group containing polymer or oligomer comprising on average at least one functional group per molecule, said at least one functional group selected from carboxyl, anhydride, oxirane, amino, amido, ester, oxazoline, isocyanate or any combination thereof;
• (b) from about 5 to about 98.5% by weight of the composition of at least one engineering thermoplastic;
• (c) optionally, from about 0.5 to about 94% by weight of the composition of at least one filler;
• and
• (d) optionally, up to about 93.5% by weight of an unmodified polyolefin, ethylene copolymer or ethylene terpolymer;
• wherein said process comprises:
• (i) providing said (a) at least one functional group containing polymer or oligomer and said (b) at least one engineering thermoplastic;
• (ii) melt kneading said combined (a) and (b);
• (iii) optionally adding said (c) at least one filler and further melt kneading said combined (a), (b) and (c);
• (iv) optionally adding said (d) at least one unmodified polyolefin, ethylene copolymer or ethylene terpolymer to any of said (a), (b) or (c) or combination thereof;
• and
• (v) extruding said composition into a strip, a profile, a film or sheet, a powder, or a plurality of beads, flakes, granules or pellets.