摘要:
An emulsion polymer comprising as one of its components a graft copolymer of a residual aromatic monomer-free support resin polymer and a vinyl chloride (co)polymer is disclosed. The emulsion polymer is prepared using a two-stage process. In the first stage, a chasing monomer is reacted in the presence of a support resin polymer having at least one aromatic monomer to form an polymer which is free of residual monomer and has monomeric units derived from the aromatic monomer(s). In a second stage, the vinyl chloride emulsion (co)polymer is made in situ in a reaction mixture comprising the polymer which is free of residual monomer. An extensive grafting at the second stage yields a novel water dispersible graft copolymer containing both styrene and vinyl chloride.
摘要:
A novel method of preparing an aqueous dispersion of non-uniform polyurethane particles which comprises (a) preparing at least two isocyanate-terminated polyurethane prepolymers having different hydrophilicities; (b) preparing a uniform mixture of said prepolymers; and (c) dispersing the mixed prepolymers in an aqueous medium. The resulting dispersion of the prepolymers may optionally be chain extended. This method enables the preparation of core-shell particles as well as particles of other morphologies, including “raspberry”, interpenetrating network, “salt-and-pepper”, “ice-cream cone” and particles of gradient composition. Similarly, an aqueous dispersion of two different polyurethane polymers may be obtained by first preparing at least two different isocyanate-terminated polyurethane prepolymers, preparing a uniform mixture of such prepolymers and thereafter dispersing the mixture in an aqueous medium.
摘要:
An emulsion or suspension polymer comprising a vinyl chloride polymeric core and an acrylic ester-acrylonitrile polymeric shell is disclosed. The emulsion polymer is preferably prepared using a two-stage process. In the first stage, a vinyl chloride monomer is polymerized or copolymerized to form a first phase of a polymeric hard core having a relatively high chlorine content. In a second stage, the soft acrylic ester—acrylonitrile copolymer is made in situ in a reaction mixture comprising the first phase. The product provides both flame retardancy and low MFFT, and is useful in a variety of coating and binding applications.
摘要:
A novel method of preparing an aqueous dispersion of non-uniform polyurethane particles which comprises (a) preparing at least two isocyanate-terminated polyurethane prepolymers having different hydrophilicities; (b) preparing a uniform mixture of said prepolymers, and (c) dispersing the mixed prepolymers in an aqueous medium. The resulting dispersion of the prepolymers may optionally be chain extended. This method enables the preparation of core-shell particles as well as particles of other morphologies, including “raspberry”, interpenetrating network, “salt-and-pepper”, “ice-cream cone” and particles of gradient composition. Similarly, an aqueous dispersion of two different polyurethane polymers may be obtained by first preparing at least two different isocyanate-terminated polyurethane prepolymers, preparing a uniform mixture of such prepolymers and thereafter dispersing the mixture in an aqueous medium.
摘要:
A novel method of preparing an aqueous dispersion of non-uniform polyurethane particles which comprises (a) preparing at least two isocyanate-terminated polyurethane prepolymers having different hydrophilicities; (b) preparing a uniform mixture of said prepolymers, and (c) dispersing the mixed prepolymers in an aqueous medium. The resulting dispersion of the prepolymers may optionally be chain extended. This method enables the preparation of core-shell particles as well as particles of other morphologies, including “raspberry”, interpenetrating network, “salt-and-pepper”, “ice-cream cone” and particles of gradient composition. Similarly, an aqueous dispersion of two different polyurethane polymers may be obtained by first preparing at least two different isocyanate-terminated polyurethane prepolymers, preparing a uniform mixture of such prepolymers and thereafter dispersing the mixture in an aqueous medium.
摘要:
An aqueous cationic polyurethane dispersion for waterborne digital print and other applications comprising an aqueous dispersion of polyurethane having properly positioned tertiary amino groups, e.g., tethered tertiary amino group separated from backbone by at least two intervening atoms or terminal tertiary amino groups with multiple tertiary amino groups per terminus, where said amino groups are optionally partially quaternized and/or neutralized.
摘要:
An aqueous dispersion of nanoparticle/polyurethane composites is made by forming a mixture of nanoparticles and a continuous mass of a polyurethane prepolymer in the substantial absence of water and dispersing the mixture so made in aqueous medium. Alternatively, a polyurethane prepolymer or a mixture of nanoparticles and a continuous mass of a polyurethane prepolymer is dispersed into an aqueous dispersion of nanoparticles.
摘要:
Vinyl polymers formed by bulk or solution polymerization techniques are combined with nanoparticles to produce aqueous dispersions of nanoparticle/vinyl polymer composites.
摘要:
Waterborne polyurethane dispersions are prepared by reacting (1) at least one polyisocyanate; (2) at least one active hydrogen containing compound, such as a polyol or a polyamide; and (3) preferably also at least one water-dispersability enhancing compound having water-dispersion enhancing groups, in order to form an isocyanate terminated prepolymer. The prepolymer subsequently is (1) optionally neutralized by reaction with at least one neutralizing agent, (2) dispersed in water, and then (3) chain extended by reaction with at least one of water, inorganic or organic polyamine having an average of about 2 or more primary and/or secondary amine groups, or combinations thereof. At least one plasticizer is introduced into the reaction mixture at any time during prepolymer formation or before the prepolymer is dispersed in water. The plasitcizer substantially or completely replaces other organic diluents or solvents. Various types of plasticizers may be employed, including reactive plasticizers.
摘要:
Aldehyde-telechelic polyisobutylenes free of other end groups such as alcohols, olefins, etc., are made by the hydroformylation of polyisobutylene having one or more olefinic end groups in the presence of a rhodium catalyst in combination with an organic phosphorus ligand. Very high conversions of olefin to aldehyde are obtained. Depending upon the number of aldehyde end groups per macromolecule, the telechelic polyisobutylene polymers can be utilized as precursors to form various types of block copolymers, e.g., AB, ABA, or radial block copolymers, with other polymers such as polyurethanes, polyesters, polyamines, and the like.