摘要:
Polyester compositions with a high crystallization rate obtained by mixing, at a high temperature, a polyester resin with at least one organic compound having the general formula:ROOC--Ar--OOC--Ar'--COO--Ar--COOR (I)where R represents a hydrogen atom or a C.sub.1 -C.sub.4 alkyl radical whereare Ar and Ar', either the same or different, represent a simple or condensed aromatic radical containing from 6 to 12 carbon atoms, and cooling the mixture thus obtained to room temperature.
摘要:
Polyethyleneterephthalate (PET) originating from the sorted collection of solid urban refuse can be regraded and recycled as such or mixed with virgin PET if treated at high temperature with an oxazoline of general formula: ##STR1##
摘要:
Low-crystallization-speed polyesters obtained by means of the polycondensation of 2,6-naphthalene-dicarboxy acid with at least one (C.sub.2 -C.sub.10)-(cyclo)alkylene glycol in the presence of 0.5-50 mol % of a copolymerizable reactant of general formula:ROOC--Ar--OOC--Ar'--COO--Ar--COOR (I)wherein Ar and Ar' stand for aromatic radicals, and R stands for a hydrogen atom or a (C.sub.1 -C.sub.4)-alkyl radical, or the OR group is replaced by a halogen.
摘要:
Copolyesters having an improved combination of barrier, mechanical, thermal and rheological properties and consisting of acylic and glycolic radicals, wherein the acylic radicals derive from at least isophthalic acid and 2,6-naphthalene dicarboxylic acid and at least 90% by mols of the glycolic radicals derive from ethylene glycol.
摘要:
Low-crystallization-speed polyesters obtained by means of the polycondensation of terephthalic acid with at least one (C.sub.2 -C.sub.10)-(Cyclo)alkylene glycol in the presence of 2-50 mol % of a copolymerizable reactant of general formula:ROOC-Ar-OOC-Ar'-COO-Ar-COOR (I)wherein Ar and Ar' stand for aromatic radicals, and R stands for a hydrogen atom or a (C.sub.1 -C.sub.4)-alkyl radical, or the OR group is replaced by a halogen.
摘要:
Process for the preparation of transparent re-usable bottles, which consists in moulding by injection-blow moulding cycle copolymers containing units deriving from terephthalic acid and ethylene glycol characterized in that said copolymers contain from 0.1 to 10% in moles of units deriving from aromatic diacids different from terephthalic acid and from 0.1-15% in moles of units deriving from aromatic hydroxyacids, making reference to the units deriving from terephthalic acid.
摘要:
In the present invention, a class of catalysts is described, to be used in the polycondensation stage in the synthesis of poly(ethylene terephthalate), constituted by a composition of metal derivatives in quantity so that the content of these in the final polymer is below 130 ppm.
摘要:
A parison for transparent re-usable bottles, obtained by molding by injection-blow moulding cycle copolymers containing units deriving from terephthalic acid and ethylene glycol characterized in that said copolymers contain from 0.1 to 10% in moles of units deriving from aromatic diacids different from terephthalic acid and from 0.1-15% in moles of units deriving from aromatic hydroxyacids, making reference to the units deriving from terephthalic acid.
摘要:
Process for the polymerization of unsaturated vinyl and/or vinylidene monomers which comprises reacting one or more monomers in the presence of heterocyclic initiators having a nitrogen atom bound to an oxygen atom at a temperature ranging from 100 to 130° C.
摘要:
Copolymers of acrylamide or methacrylamide, suitably modified with appropriate percentages of units deriving from comonomers of a hydrophobic nature and comonomers containing a positively charged ionic group, which are capable of effectively reducing the water permeability of a porous medium.