The invention relates to a method for manufacturing polylactide, comprising the steps of mixing lactide and a metal-coordination compound as polymerization catalyst to obtain a reaction mixture, polymerizing the lactide in liquid phase at a temperature of at least 150 C. to form polylactide in liquid phase and allowing the polylactide to solidify, characterized in that the polymerization catalyst comprises a metal-ligand coordination compound whereby the parent ligand answers the formula (I), whereby R represents an H atom, an aliphatic group, a halide atom or a nitro group and the metal is at least one of Zr and Hf. The invented catalysts show kinetics which is comparable to the kinetics of the known Sn-octoate catalyst. ##STR00001##

The present invention relates to a polyester polyol, suitable for use in the manufacture of a polyurethane, suitable for use in the manufacture of a polyurethane, the polyester polyol having an ABA-structure, in which A represents a lactide-oligomer and in which B represents an initiator. The initiator includes a reaction product having long chain dicarboxylic acid components having 18 or more carbon atoms. The invention also relates to a method for the manufacture of the polyester polyol. The invention further pertains to polyurethanes including the before-mentioned polyester polyol as well as the use of these polyurethanes as an elastomer having a high toughness. The toughness is believed to originate from the combination of the hydrophobic character of the initiator and the hydrophilic character of the lactide parts in the polyol structure. The strength of the invented polylactide-polyurethane elastomers can be further improved by incorporating a carbodiimide in the elastomer material.

Process for increasingly producing D-Lactide and meso lactide by depolymerizing by back biting polylactide (PLA) said process which comprises: (i) Depolymerizing polylactide into its corresponding dimeric cyclic esters by heating the polylactide in the presence of a catalyst system comprising a catalyst and a co-catalyst in a reaction zone at temperature and pressure at which the polylactide is molten; (ii) Forming a vapor product stream from the reaction zone; (iii) Removing the vapor product stream and optionally condense it; (iv) Recovering, either together or separately meso-lactide, D-lactide and L-lactide.

The present invention relates to a polylactic acid resin composition which has a low glass transition temperature, fusion temperature, and enthalpy of fusion, can be crystallized under commercially meaningful processing conditions, has good film processability such as extrusion properties, has excellent storage stability, and is highly biodegradable. The polylactic acid resin composition comprises a block copolymer comprising a hard segment and a soft segment, the hard segment comprising polylactic acid repeat units, and the soft segment comprising polyurethane polyol repeat units which have polyether-based polyol repeat units linearly connected via a urethane bond, wherein the soft segment is contained by 5% to 35% by weight based on the weight of the block copolymer, and the polylactic acid repeat units include poly(L-lactic acid) repeat units and poly(D-lactic acid) repeat units by a molar ratio of 94:6 to 88:12.

A curable aqueous polyurethane dispersion is formed by reacting a polyol component with a polyisocyanate. The polyol component comprises a1) at least one non-ionic polyol, a2) at least one polyol bearing at least one ionic or potentially ionic group comprising an acid group or salt thereof and a3) at least one ethylenically unsaturated monoalcohol or polyol. The polyol component contains carbon atoms from renewable resources. A method for making the curable aqueous polyurethane dispersion, uses of the aqueous polyurethane dispersion, cured polyurethanes and nail polish formulations comprising aqueous polyurethane dispersions are also disclosed.

Block copolymers include a poly -methyl--valerolactone (PMVL) block. The PMVL blocks can be formed from biosynthesized -methyl--valero lactone (MVL). The block copolymers can include hard blocks. The block copolymers can be thermoplastic elastomers.

The present invention relates to a polylactic acid resin film which has excellent flexibility, mechanical properties, stability, and transparency while having a specific biodegradability of the polylactic acid resin, and is useful as a packaging material. The present invention provides a polylactic acid resin film, comprising a polylactic acid resin including a hard segment comprising a specific polylactic acid repeating unit, and a soft segment comprising a polyurethane polyol repeating unit in which a specific polyether polyol repeating units are linearly linked via a urethane bond, wherein the total Young's modulus in both machine direction and transverse direction of the film is 350 to 750 kgf/mm.sup.2, and the total initial tensile strength in both machine direction and transverse direction of the film is 20 kgf/mm.sup.2 or more.

The present invention relates to a polylactic acid resin composition useful as a packaging material which has not only improved flexibility but also superior external appearance and superior properties such as mechanical property, transparency, heat resistance, anti-blocking property, workability of a film, and the like, and a packaging film including the same. The polylactic acid resin composition comprises a polylactic acid resin including a hard segment comprising a polylactic acid repeating unit and a soft segment comprising a polyurethane polyol repeating unit in which polyether polyol repeating units are linearly linked via a urethane bond; and a specific content of antioxidant.

Disclosed are hydrogels polymerized with a biofunctional moiety, biodegradable and permanent, designed to be implantable in a mammalian body and intended to block or mitigate the formation of tissue adhesions. The hydrogels of the present invention are characterized by comprising four structural elements: a) a polymeric backbone which defines the overall polymeric morphology, b) linkage groups, c) side chains, and d) biofunctional end groups. The hydrophobicity of the various structural elements are chosen to reduce tissue adhesion and enhance the biofunctional aspect of the end groups. The morphology of these polymers are typically of high molecular weight and have shape to encourage entanglement. Useful structures include branching chains, comb or brush, and dendritic morphologies.

A two-part laminating adhesive including a Part A polyol component and a Part B isocyanate component. The polyol component includes a polylactide polyol as a first polyol, and the isocyanate component includes an isocyanate-terminated polyurethane prepolymer. The adhesive is suited for making flexible laminates for use in packaging including food packaging.