摘要:
The invention relates to null-halocarboxylic acid esters of polyhydric, at least trihydric, alcohols, which can be used as initiators for ATRP. Using those initiators it is possible to prepare block copolymers having branched structures.
摘要:
An insulating-film forming material comprising a resin (A) that has a structure represented by formula (I):nullOnullY1nullOnullAr1nullnnullOnullY2nullOnullAr2nullmnullnull(I)wherein Y1, Y2, Ar1 and Ar2 are the same or different; each of Y1, Y2, Ar1 and Ar2represents an aromatic ring-containing divalent organic group; at least one of Y1 and Y2 is a divalent aromatic polycyclic group having a specific structure; m and n each indicates a molar percentage of the repeating units; and m falls between 0 and 100 with (mnulln)null100.
摘要:
Disclosed is a method for preparing a biodegradable polymer in the form of uniform powder or spherical particles by dispersion polymerization without a grinding step. The method for preparing a biodegradable polyester includes dispersing a monomer in the presence of a catalyst in a dispersion solvent to form a solid or liquid phase for dispersion polymerization and thereby to yield a biodegradable aliphatic polyester in the form of spherical particles or powder, the monomer comprising a mixture of a first compound (e.g., lactide or glycolide) and a second compound being selected from the group consisting of polyhydric alcohols (e.g., glycerin, erythritol, penterythritol or dipentaerythritol) and carprolactone. The present invention readily prepares a biodegradable polymer having a high molecular weight in the form of uniform powder or spherical particles.
摘要:
Powder coating compositions based on carboxyl- and/or hydroxyl-containing polyesters, crosslinkers, and other customary additives for coatings having a matt appearance and methods for providing coatings having a matt appearance.
摘要:
Polyestercarbonates are disclosed which comprise structural units derived from at least one bisphenol derived from terpene precursors, at least one aromatic dihydroxy compound comonomer, at least one diester derived from a C1-C40 linear or branched divalent hydrocarbyl radical, and at least one carbonic acid diester. Also disclosed are methods to make the polyestercarbonates and articles derived therefrom.
摘要:
The invention provides a decomposable resin composition, which is stable at the time of use and which quickly decomposes when discarded. According to the present invention, there is provided a resin composition comprising an agent generating an acid or a base upon response to light or heat together with a hydrolyzable and biodegradable resin. The decomposable resin composition can promote decomposition of the polymer by generating an acid or a base in the resin by carrying out light irradiation and/or a heat treatment at a desired time and can control the decomposition speed of the polymer by controlling the generation amount of an acid or a base.
摘要:
The present invention relates to polymeric networks, which are characterised by particular mechanical properties and which, furthermore, allow the control of thermal and mechanical properties by simple variation of the components.
摘要:
A process for making a high molecular weight (co)polycarbonate resin is disclosed. The process entails (i) obtaining at least one member selected from the group low molecular weight residue (weight average molecular weight 15,000 to 30,000) of aromatic (co)polycarbonate production, waste of (co)polycarbonate production, remainders of (co)polycarbonate production and (co)polycarbonate recyclate (ii) melting the said member in a suitable vessel to obtain a melt and (iii) feeding the melt into a reactor optionally along with at least one bisphenol or oligocarbonate having terminal OH groups and further optionally with a transesterification catalyst, and (iv) subjecting the melt to transesterification reaction at a temperature of 250 to 350null C., at a pressure below 5 mbar and residence time of 0.02-4 hours.
摘要:
A process for producing a wholly aromatic polyester which is excellent in heat resistance, mechanical properties and yet color and has a high degree of polymerization by melt polymerizing a dicarboxylic acid and a diol directly on an industrial scale at a low cost in a short period of time without esterifying the dicarboxylic acid or diol in advance. To produce the wholly aromatic polyester by reacting and molding an aromatic dicarboxylic acid such as terephthalic acid, an aromatic diol such as 2,2-bis(4-hydroxyphenyl)propane and a diaryl carbonate by heating, a combination of a specific pyridine compound and an alkali metal (bi)carbonate, a combination of a specific pyridine compound and an organic tin compound or a specific titanium compound is existent as a catalyst. Thereby, the wholly aromatic polyester having the above properties is obtained.
摘要:
Thermally stable polymers comprising chain members derived from at least one 1,3-dihydroxybenzene moiety and at least one aromatic dicarboxylic acid moiety, said polymer being substantially free of anhydride linkages linking at least two mers of the polymer chain, are prepared using an interfacial method comprising the steps of: (a) combining at least one 1,3-dihydroxybenzene moiety and at least one catalyst in a mixture of water and at least one organic solvent substantially immiscible with water; (b) adding to the mixture from (a) a controlled stoichiometric ratio of at least one acid chloride and at least one base while maintaining the pH between about 4 and about 8.5, and (c) adjusting the pH of the reaction mixture to a value in the range of about 7 and about 9 following complete addition of acid chloride, and stirring the reaction mixture for a time sufficient to destroy any anhydride linkages in the polymer chain.