摘要:
Polyesters with a high crystallization rate synthesized by the polycondensation of terephthalic acid with at least one C.sub.2 -C.sub.4 alkylenic glycol in the presence of 0.1-1.5 mol % of a copolymerizable reagent having the general formula:ROOC--Ar--OOC--Ar'--COO--Ar--COORwhere Ar and Ar'represent aromatic radicals and R represent a halogen, a hydrogen atom or a C.sub.1- C.sub.4 alkyl radical.
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:
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:
A process for the preparation of mixed silica-zirconia sols and mixed oxides in spherical form, comprising mixing a silicon alkoxide with a solution of an inorganic zirconium salt in a low molecular weight polyol and subjecting the intermediate thus formed to acid hydrolysis in a water medium.
摘要:
Formed articles having improved surface properties, such as wettability, printability, adhesion, antistaticity and clouding resistance, consisting of a polymeric finished article or semi-finished article coated on at least a surface with a polyhydroxethylacrylate layer, preferably prepared by means of plasma polymerization.
摘要:
Procedure for the continuous fractionation of polymers dissolved in a solvent, which includes at least one complete cycle of the following operations:a. precipitation of a first fraction of polymer inside a first reaction vessel containing the solution;b. transferring the remaining solution into a second reaction vessel and collecting the above first fraction of polymer precipitated in the above first reaction vessel;c. precipitation of a second fraction of polymer inside the second reaction vessel; andd. recycling the remaining solution in the first reaction vessel and collecting the above second fraction of polymer precipitated in the above second reaction vessel.
摘要:
A mixed-matrix composite material reinforced with continuous fibre comprising a flexible sheath of thermoplastic polymer covering a multifibre filament impregnated with a powder consisting of:1-99% by weight, and preferably 50-95%, of a thermoplastic polymer;99-1% by weight, and preferably 50-5%, of a reactive monomer and/or prepolymer which on thermal stressing is able to undergo crosslinking and/or molecular weight increase.
摘要:
The invention provides acrylic-based heat-resistant bicomponent structural adhesives comprising:a) a first adhesive component consisting of:an elastomer;a monofunctional acrylic monomer;a free radical generator;a solution stabilizer;an adhesion promoter;a cross-linking agent;a heat stabilizer for the adhesive, chosen from maleimide derivates containing acrylic residues; andb) a second component activating the first adhesive component and consisting of:a mixture of aldehyde-amine condensation products;an organic salt of a metal of the first transition series of low oxidation state.
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:
Double-component acrylic adhesive compositions are disclosed, in which:(a) the adhesive component comprises a mono-functional acrylic monomer, a loro-sulfonated polyolefin and a crosslinker selected from difunctional silicon derivatives;(b) the activating component is a typical aldehyde-amine condensation product.