Solvay Solexis S.p.a.

Solvay Specialty Polymers Italy S.p.a.

Giovanni Comino

Margherita Albano

Milena Stanga

Marco Apostolo

Claudia Manzoni

Matteo Fantoni

Liubov Chernysheva

Julio A Abusleme

Giulio Brinati

Valeriy Kapelyushko

Bradley Lane Kent

Stefano Arrigoni

Marco Dossi

Laura Ponta

Marco Cristini

The invention pertains to a method for emulsion polymerization of at least one fluoromonomer, said method comprising: (i) providing at least one aqueous emulsion comprising at least one surfactant and a monomer mixture [mixture (M)] comprising at least one fluoromonomer [monomer (F)] and optionally at least one additional monomer, and at least one RAFT/MADIX agent; (ii) initiating the polymerization of said monomer mixture in said aqueous emulsion adding at least one radical initiator; (iii) continuing the polymerization by adding additional amounts of said mixture (M) and said RAFT/MADIX agent, until converting the targeted amount of said mixture (M), and (iv) terminating the polymerization and recovering a latex of fluoropolymer [polymer (F)]; wherein the amount of RAFT/MADIX agent is comprised between 0.1 and 0.5% moles, with respect to the total amount of converted monomers of said monomer mixture, and wherein the amount of said RAFT/MADIX agent present in the aqueous emulsion when initiating the polymerization in step (ii) is of at most 50% with respect to the total amount of said RAFT/MADIX agent.

Method for the controlled polymerization of fluoromonomers

A (per)fluoroelastomer composition having improved plasma resistance comprising at least one (per)fluoroelastomer [fluoroelastomer (A)] and from 0.1 to 50 weight parts per 100 parts by weight of said fluoroelastomer (A) of alkaline-earth metal carbonate particles [particles (P)]. Each particle comprises a core consisting essentially of at least one alkaline-earth metal carbonate and a shell consisting essentially of at least one Group IV transition metal compound.

Fluoroelastomer composition

The invention pertains to a process for manufacturing a fluoroelastomer [fluoroelastomer (A)] having a heat of fusion of less than 5 J/g as measured by ASTM D-3418-08, said method comprising emulsion polymerizing vinylidene fluoride (VDF) in the presence of at least one additional fluorinated monomer, in an aqueous polymerization medium, said method comprising polymerizing VDF and said additional fluorinated monomer(s) in the presence of a redox radical initiator system comprising: &#x2014;at least one organic oxidizing agent [agent (O)]; &#x2014;at least one organic reducing agent [agent (R)]; wherein agent (O) is fed to said polymerization medium separately from agent (R), so that agent (O) comes in contact with agent (R) exclusively in said polymerization medium comprising VDF and optional additional monomer(s), to fluoroelastomers having low amount of chain defects and low amount of polar end groups, notably obtainable from said process, and to curable compositions therefrom.

Method for manufacturing fluoroelastomers

The invention pertains to a hyperbranched (per)fluoroelastomer [fluoroelastomer (B)] comprising recurring units derived from a bis-olefin [bis-olefin (OF)] having general formula (I): wherein R, R, R, R, Rand R, equal or different from each other, are H or C-Calkyl; Z is a linear or branched C-Calkylene or cycloalkylene radical, optionally containing oxygen atoms, preferably at least partially fluorinated, or a (per)fluoropolyoxyalkylene radical, said fluoroelastomer (B) having a slope in G' curve such that the ratio: G&#x2032;/G&#x2032;is of less than 10, when determined at 260&#xb0; C. according to ASTM D4440 standard, wherein G&#x2032;100 is the storage modulus at a shear rate of 100 rad/sec and G&#x2032;is the storage modulus at a shear rate of 0.01 rad/sec, to compositions comprising the same, and to a process for their manufacture.

Hyperbranched fluoroelastomer additive

The invention pertains to a process for cryogenic milling mixtures of (per)fluoroelastomers and semicrystalline thermoplastic VDF polymers, and to free-flowing micronized pellets obtainable therefrom, said micronized pellets advantageously yielding, after extrusion and compounding, excellent mechanical properties, even improved over those of base fluoroelastomer matrix.

Milling process

The invention pertains to a low viscosity curable (per)fluoroelastomer [fluoroelastomer (A)] having a number-averaged molecular weight of 3 000 to 45 000, said (per)fluoroelastomer comprising at least 1% moles, with respect to the total moles of recurring units, of recurring units derived from at least one (per)fluoromethoxyalkylvinylether of formula (I):CFX'&#x2550;CX&#x2033;OCFOR&#x2003;&#x2003;formula (I)wherein X&#x2032; and X&#x2033;, equal to or different from each other, are independently H or F; and Ris selected from the group consisting of C-C(per)fluoroalkyls, linear or branched; C-Ccyclic (per)fluoroalkyls; and C-C(per)fluorooxyalkyls, linear or branched, comprising from 1 to 3 catenary ethereal oxygen atoms [monomer (M)].

Low viscosity fluoroelastomers

A (per)fluoroelastomeric composition curable by peroxidic way comprising for 100 phr of (per)fluoroelastomer: 

(Per)fluoroelastomeric compositions

This invention pertains to sealing articles of vulcanized (per)fluoroelastomer compositions incorporating particles of a vinylidene fluoride (VDF) polymers having a Shore A hardness of at least 85 when determined according to ASTM D 2240 Type A Durometer method, and a compression set of less than 30%, when determined according to ASTM D395 at 200&#xb0; C. for 70 h on O-ring according to ASTM D1414, and to a process for their manufacture by vulcanizing-molding and thermal post-treating at a temperature above the melting point of the VDF polymer.

Vulcanized (per) fluoroelastomer sealing articles

Extrudable (per)fluoroelastomer compositions comprising crosslinkable (per)fluoroelastomers having:

A fluoroelastomer composition comprising: The incorporation of the polymer (F) in the fluoroelastomer composition as described above enables easier processing of the fluoroelastomer composition, both in injection molding and extrusion molding technologies, yielding improved behavior in mold release, mold fouling, and aspect surface of the molded parts.

Vulcanizable fluoroelastomer compositions comprising:

Vulcanisable fluoroelastomeric compositions

A (per)fluoroelastomeric composition curable by peroxidic way comprising: 

A crosslinking system of perfuoroelastomers curable by peroxidic way comprising: 

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Monza, Italy

Giovanni Comino