摘要:
La présente invention concerne un coréticulat polyester-silicone dégradable par hydrolyse qui est le produit de réaction :
a) - d'au moins un diorganopolysiloxane présentant par molécule des fonctions hydroxyle liées chacune aux atomes de silicium par une liaison Si-C, b) - un oligomère polyester polylactique et/ou polyglycolique α,ω-diol, c) - un polyisocyanate organique.
Les coréticulats selon l'invention sont en particulier utilisables comme matrice contenant un principe actif en vue de la libération contrôlée du principe actif par simple érosion par hydrolyse de cette matrice.
摘要:
La présente invention se rapporte à des polyuréthanes biodégradables à base d'un prépolymère de polyol et d'un dérivé de L-lysine ayant au moins 2 groupes isocyanate. Le prépolymère de polyol est de préférence constitué par un prépolymère de polyol de polyester obtenu par polymérisation par décyclisation de L-lactide, de glycolide et/ou de lactone avec un polyol cyclique. Ces nouveaux polyuréthanes peuvent être utilisés dans la production de différents types de produits biomédicaux, tels que peau artificielle, pansements vulnéraires, veines artificielles, greffes de nerfs, etc.
摘要:
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.
摘要:
Block copolymers include a poly β-methyl-δ-valerolactone (PMVL) block. The PMVL blocks can be formed from biosynthesized β-methyl-δ-valero lactone (MVL). The block copolymers can include hard blocks. The block copolymers can be thermoplastic elastomers.
摘要:
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.
摘要:
A coated substrate having on one surface thereof a coating composition comprising a polyurethane, said polyurethane comprising the reaction product of: i) at least one isocyanate; and, ii) a polyol which is a random copolymer comprising from 30 to 85 wt.% lactoyl units and at least one further monomer. The polyol may be further characterized by a number average molecular weight (Mn) of from 800 to 5000, preferably from 800 to 3500 g/mol.
摘要:
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.