Heat-expandable microcapsules each having a core/shell structure which includes a core and a shell, wherein the core contains a volatile substance and the shell contains a polymer, the polymer being obtained by reacting a monomer mixture with an organic peroxide represented by general formula (1):

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wherein the R.sup.1 moieties each independently represent a C.sub.2-12 unsaturated hydrocarbon group, the unsaturated hydrocarbon group being optionally separated by one or more of COO, OCO, and O.

The microcapsules and process of making describe a novel core shell microcapsule. The microcapsule incorporates a polysaccharide such as chitosan into the microcapsule wall forming the shell. The microcapsule shell is formed by dissolving chitosan into a material of structure

##STR00001##

wherein each R is independently selected from hydrogen, C.sub.1 to C.sub.8 alkyl, or a cyano group; and each y is independently an integer from 1 to 8, and reacting with a multifunctional (meth)acrylate.

The present invention relates to thermally expandable microspheres at least partially prepared from bio-based monomers and to a process of their manufacture. The microspheres comprise a thermoplastic polymer shell encapsulating a blowing agent, wherein the thermoplastic polymer shell comprises a polymer being a homo- or copolymer of a lactone according to formula (1):

##STR00001##

wherein each of R.sub.1, R.sub.2, R.sub.3, R.sub.4, separately from one another, is selected from the group consisting of H and an alkyl group preferably with 1-4 carbon atoms. The invention further provides expanded microspheres, which can be used in a variety of applications.

A polymerizable system includes a curable composition and one or more encapsulated initiator particles. The curable composition can include one or more 1,1-disubstituted alkene compounds and the encapsulated initiator particles can include one or more polymerization initiators encapsulated by a cured composition. The cured composition includes one or more 1,1-disubstituted alkene compounds.

Microcapsules and techniques for the formation of microcapsules are generally described. In some embodiments, the microcapsules are formed in an emulsion (e.g., a multiple emulsion). In some embodiments, the microcapsule may be suspended in a carrying fluid containing the microcapsule that, in turn, contain the smaller droplets. In some embodiments, the microcapsules comprise a shell and a droplet at least partially contained within the shell (e.g., encapsulated within the shell), and may be suspended in a carrier fluid. In certain embodiments, the shell is a hydrogel comprising a poly(acid). In some cases, the poly(acid) is a polyanion. In some cases, the shell does not comprise a poly(base) or polycation (e.g., a polycationic poly electrolyte). In some embodiments, the microcapsules comprise a shell comprising a poly(acid) and a poly(anhydride).

A tracer particle is provided. The tracer particle includes: a core structure; a nucleic acid molecule immobilized on the core structure; and a shell layer covering the core structure and the nucleic acid molecule; wherein the core structure has a first porosity, the shell layer has a second porosity, and the first porosity is greater than the second porosity.

A method for producing an aerogel granule having a hydrophobic-hydrophilic bipolar core-shell structure combines an aerogel precursor having a hydrophilic structure with another aerogel precursor having a hydrophobic structure. The method comprises the steps of: mixing a hydrophilic alkoxysilane compound, a hydrophobic alkyl-substituted alkoxysilane compound, and an organic solvent to form a mixture; adding an acidic catalyst to the mixture to perform hydrolysis; adding a basic catalyst to the hydrolyzed mixture to perform condensation, and during the condensation adding a dispersion solvent to the hydrolyzed mixture and stirring the hydrolyzed mixture to gelate so as to form the aerogel granule having a hydrophobic-hydrophilic bipolar core-shell structure.

The present invention relates to thermally expandable microspheres at least partially prepared from bio-based monomers and to a process of their manufacture. The microspheres comprise a thermoplastic polymer shell encapsulating a blowing agent, wherein the thermoplastic polymer shell comprises a polymer being a homo- or copolymer of a lactone according to formula (1): ##STR00001##
wherein each of R.sub.1, R.sub.2, R.sub.3, R.sub.4, separately from one another, is selected from the group consisting of H and an alkyl group preferably with 1-4 carbon atoms. The invention further provides expanded microspheres, which can be used in a variety of applications.

The present invention relates to a process for the production of a polyurethane reinforced composite including mixing (A) a Polyisocyanate component including di- or Polyisocyanates (a) and (B) a polyol component including compounds having at least two groups reactive toward isocyanates (b), catalyst (c) and optionally further additives, to form a reaction mixture, contacting the reaction mixture with the reinforcing material at temperatures of less than 100 C. and curing the reaction mixture at temperatures of more than 100 C. to form a polyurethane reinforced composite. The catalyst (c) includes microencapsulated polyurethane catalyst which includes a capsule core, containing polyurethane catalyst, and an acrylic copolymer capsule shell. An average particle size D(0,5) of the microcapsules is 1 to 50 m. The invention further relates to a polyurethane reinforced composite obtainable by a process according to the invention.

Provided are stimuli-responsive composite particles which contain microcapsules containing an electron-donating dye precursor and particles of an electron-accepting compound causing the electron-donating dye precursor to develop color, in which the microcapsules are attached to at least a portion of the surface of each of the particles of the electron-accepting compound. Also provided is a manufacturing method of the stimuli-responsive composite particle.