Methods for producing highly spherical particles that comprise: mixing a mixture comprising: (a) nanoclay-filled-polymer composite comprising a nanoclay dispersed in a thermoplastic polymer, (b) a carrier fluid that is immiscible with the thermoplastic polymer of the nanoclay-filled-polymer composite, optionally (c) a thermoplastic polymer not filled with a nanoclay, and optionally (d) an emulsion stabilizer at a temperature at or greater than a melting point or softening temperature of the thermoplastic polymer of the nanoclay-filled-polymer and the thermoplastic polymer, when included, to disperse the nanoclay-filled-polymer composite in the carrier fluid; cooling the mixture to below the melting point or softening temperature to form nanoclay-filled-polymer particles; and separating the nanoclay-filled-polymer particles from the carrier fluid.

A method of forming a barrier to overcome lost circulation in a subterranean formation. The method includes injecting a polymer-sand nanocomposite into one or more lost circulation zones in the subterranean formation where the polymer-sand nanocomposite is formed from sand mixed with a polymer hydrogel. Further, the polymer hydrogel includes a hydrogel polymer, an organic cross-linker, and a salt. The sand additionally comprises a surface modification. The associated method of preparing a polymer-sand nanocomposite lost circulation material for utilization in forming the barrier is provided.

Compositions for removing contaminants from plastics processing equipment are described herein. The compositions may include a polymeric carrier component, an oxidizing agent, an abrasive and/or a gas agent. Methods of preparing the compositions described herein and methods of removing contaminants from plastics processing equipment are also described.

A method for continuously preparing graphene powder directly dispersed in an organic system, including: mixing an aqueous graphene oxide dispersion, an emulsifier and an oil-soluble monomer followed by pH adjustment and dispersing to obtain a pre-emulsified dispersion; subjecting the pre-emulsified dispersion to an emulsion polymerization reaction in the presence of an initiator; introducing a reducing agent to reduce graphene oxide; and subjecting the reaction mixture after emulsion polymerization to spray drying to obtain the graphene powder. Equipment used in the preparation method is also provided herein.

A vitrimer composition includes a first plurality of polymer backbones cross-linked with cross-linkers that include at least one siloxane moiety having formula 1:

##STR00001##

wherein R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are each independently H or C.sub.1-6 alkyl. A catalyst that accelerates siloxane exchange is dispersed within the first plurality of polymer backbones.

The present invention relates to a process for impregnating a fibrous substrate consisting of long fibers by a liquid (meth)acrylic mixture mainly containing methacrylic and/or acrylic components. The invention also relates to such a (meth)acrylic mixture and its composition, said (meth)acrylic mixture comprising a (meth)acrylic syrup and an aqueous dispersion of radical initiator. The invention also relates to a process for manufacturing mechanical parts or structured elements or articles made of composite material by impregnating the fibrous substrate with the (meth)acrylic mixture then polymerizing said (meth)acrylic mixture, and also such parts obtained according to said manufacturing process and used in varied fields such as the automotive industry, aeronautics, or else construction.

The present invention relates to a polymer composition comprising a (meth)acrylic polymer and a multistage polymer. In particular the present invention it relates to polymer composition comprising a (meth)acrylic polymer and a multistage polymer that can be used as a masterbatch. More particularly the present invention relates also to a process for preparing a polymer composition comprising a (meth)acrylic polymer and a multistage polymer by spray drying or coagulation.

The present invention relates to a composite material obtained by in situ polymerization of a thermoplastic resin with a fibrous material. More particularly the present invention relates to a polymeric composite material obtained by in-situ polymerization of a thermoplastic (meth)acrylic resin and a fibrous material containing long fibers and its use, a process for making such a composite material and manufactured mechanical or structured part or article comprising this polymeric composite material.

An optical film is provided in which a wavelength dispersion characteristic at a wavelength of 400 nm to 800 nm satisfies the following general formula (1):

[00001]$\begin{array}{cc}\frac{\Delta \lambda }{\Delta 550}=a{\lambda }^{-b}& \left(1\right)\end{array}$

wherein a has a value of 1500<a<6600, b has a value of 1.17<b<1.27, Δλ represents a photoelastic coefficient at an arbitrary wavelength λ nm in a range of 400 nm to 800 nm, and Δ550 represents a photoelastic coefficient at a wavelength of 550 nm and which has a thickness of 10 m to 1000 m, can be provided.

The invention relates to a film comprising an interpenetrating network, its uses and processes for making the same. The film produced displays good durability, chemical resistance and transparency. The film is produced from an interpenetrating network formed as a colloidal suspension in an organic solvent and a particulate solid.