摘要:
The kinetics of crystallization of high polymers from the molten state is modified by adding to the polymers before the thermoforming step low amounts of a nucleating agent consisting of solid particles of crystalline zeolites treated with high-boiling acrylcarboxylic acid or sulphonic acid.
摘要:
Self-extinguishing polymeric compositions are taught comprising, expressed in % by weight referrred to the total composition:a) from 1 to 25% of at least an organic aliphatic, cycloaliphatic, aromatic halogen-derivative;b) from 10 to 40% of at least an adduct between an inorganic halide and a zeolite;c) from 0.5 to 5% of an organic reactive agent capable of modifying the polymeric matrix at the combustion temperature, comprising at least an organic compound which generates radicals at said temperature and at least a cross-linking agent;d) the remaining part being composed of at least a thermoplastic polymer and/or copolymer.
摘要:
Nucleants for thermodegradable crystalline polyolefines made up of zeolitic molecular sieves modified with at least one arylcarboxylic acid. These nucleants may be added before or during the macroradicalic degradation of the polyolefines and allow products having a high degree of nucleation to be obtained.
摘要:
Cross-linkable polymer compositions of an olefinic polymer modified by an unsaturated silane bearing hydrolyzable groups and a zeolite, wherein the zeolite is an adduct of a zeolite in finely divided form having a water content not higher than 3% by weight modified at a temperature of at least 150.degree. C. with at least one carboxylic and/or sulfonic organic acid.
摘要:
Crystalline propylene (co)polymers modified by grafting with a vinylpolybutadiene having 1,2-structure content of at least 10%.Said (co)polymers are reacted with a liquid vinylpolybutadiene in the presence of a non-peroxidic radical initiator at a temperature in the range 200.degree. to 350.degree. C., the liquid vinylpolybutadiene having a 1.2-structure content of at least 10% and being generally used in amounts within the range 0,5 to 20% by weight.
摘要:
Soft and low-density foam materials, obtained by means of an extrusion expansion (with physical blowing agents) of particular copolymers of ethylene with vinylacetate (and/or with alkyl esters of acrylic or methacrylic acid), are found to be very suitable for the manufacture of expanded articles with little shrinkage after expansion, free from creases on the surface or cracks on the cell walls, and having excellent characteristics, higher compressive strength and so on.
摘要:
A process is described for imparting a better adhesion between reinforcing materials and a plastic matrix, characterized in that it comprises the steps of treating the reinforcing material surface with at least one organic compound of a tetravalent metal selected from the group consisting of zirconium and tin, at a temperature ranging from 250.degree. to 650.degree. C., of applying onto the reinforcing material surface so treated, at a lower temperature, at least one silane coupling agent and, finally, of drying the so-treated reinforcing material.
摘要:
Compositions based on ethylene/vinylacetate copolymers provided with self-extinguishing properties and suitable for the preparation of foamed materials, comprising for 100 parts by weight of the EVA copolymers:from 5 to 10 parts by weight of at least a bromodiphenylether containing at least 3 bromine atoms;from 2 to 4 parts by weight of a metal oxide selected from antimony, bismuth and tungsten oxides; andfrom 0.1 to 1 part by weight of a compound having general formula ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, equal or different from each other, can by hydrogen, chlorine, bromine, aliphatic hydrocarbon radicals containing from 1 to 6 carbon atoms, cyclohexyl or phenyl radicals, the nitro group or the --CN group.R.sub.5, R.sub.6, equal or different, can be hydrogen, chlorine, bromine, aliphatic hydrocarbon radicals containing from 1 to 3 carbon atoms, or alkoxy radicals containing 1 to 4 carbon atoms or ##STR2## groups, R.sub.7 being an alkyl radical containing from 1 to 3 carbon atoms.
摘要:
Glass having improved hydrolytic and chemical resistance as well as improved water repellency and mechanical characteristics is obtained by reacting the glass surface with an organoborosiloxane polymer, substituted by one or more of alkyl, aryl, alkoxy, acyl radicals, said organoborosiloxane polymer containing no free hydroxy groups in the presence of one or more organic Ti, Zr, Sn, v compounds at a temperature comprised between 200.degree. and 400.degree.C in order to obtain, through a grafting reaction, a superficial layer of modified glass.
摘要:
Oil-repellent polymeric compositions prepared by a process which comprises:a) adding at least a radical starter and at least a perfluoropolyether to at least a molten thermoplastic polymer;b) intimately mixing the resulting composition for a time which is sufficient to obtain macroradicals from the polymer; andc) cooling the final composition to room temperature.