摘要:
The invention relates to a process for preparing a polymer in which in situ polymerization of monomers takes place in the presence of a catalyst, in which the monomers are obtained by in situ activation of precursor monomers.According to the invention a premature polymerization is avoided, but polymerization only starts at the desired moment.
摘要:
High modulus and high strength articles of polyvinylalcohol are obtained by thermoreversible gelation of a 5-50 wt. % solution of a polyvinylalcohol with an M.sub.W of 2.5.times.10.sup.4 to 5.times.10.sup.5 in water, followed by solvent removal and high stretching.Pref. gelation is obtained by cooling to a temperature of at least 40.degree. C. below the gelation temperature.With this process low costs of solvent removal and regeneration are obtained.
摘要:
The invention relates to a process for the production of an electrically conducting article, in which process a polymer composition, comprising a carrier polymer, is stretched and, during stretching of the polymer composition, polymerisation of monomers takes place to form a conjugated polymer, characterised in that the polymer composition contains precursor monomers prior to stretching and the monomers are obtained by activating precursor monomers during the stretching step. It has been found that using the process according to the invention articles can be obtained which, in addition to good electrically conducting properties, also have good mechanical properties.
摘要:
The invention relates to a process for the preparation of an intrinsically conductive moulding compound obtained by in situ polymerization of monomers which form an intrinsically conductive polymer after polymerization, in the presence of a matrix polymer and a catalyst, the matrix polymer being dissolved in an essentially solvent free monomer, after which the solution obtained is brought into the desired form and the monomers are polymerized in situ in the presence of a catalyst.Moulding compounds obtained with the process accordingly to the invention can be used in batteries electronic components (diodes, transistors), electrical wiring, coatings and in EMI-shielding attributes.
摘要:
Polyvinyl alcohol articles of high strength and modulus are obtained by thermoreversible gelation of a polyvinyl alcohol solution, extraction of the gelation solvent using a mixture of a low alcohol or ketone and water, followed by high stretching. Preferably, a mixture of 5-80 vol. % of acetone and 95-20 vol. % of water is used as extractant. With this process extraction times of only 3-10 minutes are required.
摘要:
The invention relates to a halogen free flame retardant polyester composition suitable for use as a molding composition for making lampholders, comprising (A) a polymeric material consisting for at least 50 wt. %, relative to the total weight of the polymeric material, of a thermoplastic polyester; (B) a flame retardant system in an amount of 11-35 wt. %, relative to the total weight of (A), (B) and (C), and consists of: melamine cyanurate, and optionally one or more of the following flame retardant components: another phosphorus-free nitrogen based organic flame retardant compound, a phosphorus containing flame retardant excluding elementary phosphorus, in an amount of less than 1 wt. %, relative to the total weight of (A), (B) and (C); an inorganic flame retardant synergist, and an organic flame retardant synergist (C) a fibrous reinforcing agent in an amount of 5-35 wt. %, relative to the total weight of (A), (B) and (C); and (D) a mould release agent in an amount of at least 0.01 wt. %, relative to the total weight of (A), (B) and (C).
摘要:
The method concerns preparing a polymer composition containing an electrically conductive polymer which is formed, in the presence of a catalyst, from polymerizable monomer units that are converted from non-polymerizable precursor monomers with the aid of a sufficiently energy-intense light source. In this method according to the invention is that the precursor monomers have a structure according to formula (I). The method according to the invention makes it possible to very easily and rapidly, and thus economically, prepare a polymer composition containing an electrically conductive polymer. Furthermore, the method according to the invention permits a polymer composition to be produced that contains an electrically conductive polymer in specifically pre-selected areas.
摘要:
A microporous film with improved resistance to elevated temperatures from a first, thermoplastic polymer, the internal and external surfaces of the film being provided with a continuous coating layer of a second polymer having a higher softening temperature than the first polymer and process for coating a film of a first polymer with a layer of a second polymer.
摘要:
Polyacrylonitrile articles, such as filaments, tapes and films, having high tensile strength and modulus, and prepared by adding to a solution of polyacrilonitrile with a molecular weight above 3.times.10.sup.5, preferably above 5.times.10.sup.5, a minor amount of a bivalent metal compound, converting the solution into a solvent containing article, cooling this article to form a gel article, removing from this gel the solvent and metal compound, and stretching the resulting article at increased temperature. With this process filaments with a tensile strength above 1.2 GPa and a modulus above 16 GPa can be obtained.
摘要:
The present invention relates to a process for the production of a solid state post condensated fiber reinforced polymer composition, preferably suitable for a brake booster, comprising the steps of: i) compounding a polymer composition comprising: (A) polyethylene terephthalate (PET) and/or polybutylene terephthalate (PBT) with a Mz/Mw