Reinforced thermoplastic moulding materials (I) contg. (i) biodegradable polymers selected from (a1) aliphatic or partly aromatic polyesters, (a2) thermoplastic aliphatic polyester- urethanes, (a3) aliphatic-aromatic polyester-carbonates and (a4) aliphatic polyester-amides, with (ii) wood dust, natural fibres, natural minerals, cellulose or cellulose derivs. as reinforcing fillers. Also claimed are mouldings, moulded parts and extruded prods. made from (I). Pref. polyesters (a1) are derived from (A) linear diols and/or opt. cycloaliphatic diols and/or small amts. of branched diols, opt. with small amts. of higher functional alcohols, together with aliphatic and/or opt. aromatic di-acids, opt. with small amts. of higher functional acids, or (B) acid- and alcohol-functionalised components, or (a1) may be a mixt. or copolymer of (A) and (B); aromatic di-acids comprise not more than 50 wt% of the acid component, which may also be in the form of derivs.
