摘要:
Tape comprising a polymer composition, said polymer composition comprising at least one fluoropolymer and a modifier consisting of at least one aromatic polyimide chosen from aromatic polyamide-imides and aromatic polyesterimides, and, optionally in addition, at least one aromatic polyimide chosen from aromatic polyimides other than aromatic polyamide-imides and aromatic polyesterimides, said modifier being comprised in the polymer composition in an amount of up to 75 wt. % (based on the total weight of the polymer composition). Article comprising said tape. Processes especially well-adapted for manufacturing said tape. Use of the above modifier as an additive of a polymer composition comprising a fluoropolymer, to increase the abrasion resistance either of a tape comprising said polymer composition, or of an article comprising an outermost layer which covers at least partially the article, said outer most layer comprising a tape comprising said polymer composition.
摘要:
Fluoropolymers comprising a fluoroelastomer matrix incorporating therein particles of a semicrystalline fluoropolymer formed of tetrafluoroethylene (TFE) homopolymers or copolymers, wherein the average particle sizes of the semicrystalline fluoropolymer latex range from 10 to 100 nm.
摘要:
Mixtures of fluoropolymer dispersion, wherein: a) a dispersion is formed by TFE (co)polymers with average particle sizes in the range 180–400 nm; b) another dispersion selected from: 1) (co)polymer dispersion of TFE; 2) thermoplastic copolymers of TFE; the average particle sizes of dispersion b) range from 20 to 60 nm; the ratio between the particle sizes of dispersion b) compared with those of dispersion a) is lower than 0.3.
摘要:
Aqueous dispersions of fluoropolymers containing as stabilizer from 1 to 30% by weight with respect to the fluoropolymer, of a non ionic surfactant having the following structure: CH3(CH2)nO(C3H6O)p(CH2CH2O)mH (I) wherein: n is in the range 8-20, preferably 12-15; m is in the range 5-20, preferably 7-12; p is in the range 1-8, preferably it is 1 or 2.
摘要:
A formulation based on the PTFE, homopolymer or modified, comprising: 1) latex of said PTFE having a particle diameter between 5 and 100 nm, comprising an anionic fluorinated surfactant in an amount in the range 2-25% by weight based on the PTFE; 2) non ionic fluorinated surfactant added to the PTFE latex in an amount in the range 18-60% by weight based on the PTFE.
摘要:
Process for the preparation of a dispersion based on homopolymers/copolymers of tetrafluoroethylene (TFE), said dispersion having a bimodal or multimodal distribution of the particle diameters, wherein the fraction of small particles is in the range 1.5-35% by weight calculated on the dry product; the ratio between the average diameter of the small particles with respect to the average diameter of the dispersion obtained from the polymerization being in the range 0.02-0.6; said process comprising the following essential steps: (a) preparation of an aqueous microemulsion comprising fluorinated surfactants and (per)fluoropolyether oils (PFPE); (b) feeding of the microemulsion into the polymerization reactor; (c) feeding of at least one fluorinated surfactant.
摘要:
Fluoropolymers comprising a fluoroelastomer matrix incorporating therein particles of a semicrystalline fluoropolymer formed of tetrafluoroethylene (TFE) homopolymers or copolymers, wherein the average particle sizes of the semicrystalline fluoropolymer latex range from 10 to 100 nm.
摘要:
Process for the preparation of tetrafluoroethylene (TFE) polymer-based dispersions having diameter average sizes in the range 0.005-0.06 &mgr;m, which comprises: a) preparation of an aqueous perfluoropolyether (PFPE) microemulsion; b) microemulsion feeding into the polymerization reactor, in such amounts so that the microemulsion perfluoropolyetheral oil phase is present in a concentration higher than 2 ml for liter of reaction medium; c) reaction medium feeding in the gaseous TFE polymerization reactor, optional addition of surfactants, stabilizers, comonomers, transfer agents; d) addition of the initiator, stabilizers, comonomers and transfer agents; e) discharge from the reactor of the polymeric latex.
摘要:
A process for polymerizing or copolymerizing fluorinated monomers, in an aqueous dispersion, by the use of radicalic starters and of fluorinated surfactants, characterized in that it is operated in the presence of perfluoropolyether having neutral end groups, being liquid under the polymerization conditions and in the form of an aqueous emulsions, in order to increase the polymerization rate.
摘要:
Fluoropolymers comprising a fluoroelastomer matrix incorporating therein particles of a semicrystalline fluoropolymer formed of tetrafluoroethylene (TFE) homopolymers or copolymers, wherein the average particle sizes of the semicrystalline fluoropolymer latex range from 10 to 100 nm.