A slurry polymerization process for the preparation of polyethylene in a reactor cascade of two or more polymerization reactors wherein monomers are polymerized in the polymerization reactors which include a reactor outlet arranged in each reactor bottom for feeding a reactor slurry to a subsequent polymerization reactor and for emptying the polymerization reactor.

A process for preparing an acrylic emulsion resin is provided by introducing specific monomers at a certain time during an emulsion polymerization process, dispersion stability and adhesion properties of the acrylic emulsion resin are improved, thereby providing an aqueous acrylic pressure-sensitive adhesive that not only has excellent initial adhesion but also has low viscosity and improved processability, and high adhesion holding power.

A propylene copolymer, a preparation method therefor, and an application thereof are provided. The copolymer forms a cross-linked network by means of a reaction between a furan-containing propylene copolymer and a small molecule of a coupling agent, thereby achieving a chemical bond connection between a polypropylene resin phase and an ethylene-propylene copolymer elastomer phase, fundamentally strengthening the force between the two phases, and improving the mechanical properties of a material. Meanwhile, the copolymer can achieve the decrosslinking of a material during melt processing such that the material has thermoplasticity, and after cooling, it can be crosslinked again to produce network structure.

A processing method of a base material sheet includes winding out the base material sheet wound up by a first core and a first porous sheet wound up by a second core, winding up by a third core the base material sheet and the first porous sheet to be overlapped with each other, and processing the base material sheet by a first processing liquid held in the first porous sheet; and winding out the base material sheet and the first porous sheet overlappingly wound up by the third core, winding up the first porous sheet by the second core, and winding up the base material sheet by the first core.

A processing method of a base material sheet includes winding out the base material sheet wound up by a first core and a first porous sheet wound up by a second core, winding up by a third core the base material sheet and the first porous sheet to be overlapped with each other, and processing the base material sheet by a first processing liquid held in the first porous sheet; and winding out the base material sheet and the first porous sheet overlappingly wound up by the third core, winding up the first porous sheet by the second core, and winding up the base material sheet by the first core.

A method for setting conditions for use of a polymerization catalyst includes a step of acquiring a physical property value derived from remaining functional groups after maintaining a temperature of a composition including a polymerization-reactive compound and a predetermined amount of a polymerization catalyst, a step of calculating a remaining functional group ratio from the physical property value, a step of calculating a reaction rate constant based on a reaction rate equation from the remaining functional group ratio, a step of calculating an activation energy and a frequency factor from the reaction rate constant using an Arrhenius plot, a step of determining whether or not the activation energy satisfies a predetermined condition for the polymerization catalyst, an step of setting an approximation equation from the frequency factor, and a step of setting an addition range with respect to the polymerization-reactive compound.

Disclosed are a heat-expandable polyvinylidene chloride microsphere and its preparation method. The preparation method comprises: by weight, dissolving 250 to 550 parts of an aqueous-phase polymerization inhibitor, 20 to 100 parts of a dispersant, and 3 to 15 parts of a co-dispersing monomer in deionized water, adjusting a pH value of the solution and cooling the solution to obtain an aqueous phase for later use; dissolving 5 to 15 parts of a cross-linking agent and 20 to 45 parts of an initiator in 1000 to 2000 parts of a mixed monomer, and cooling the solution to obtain an oil phase for later use; mixing and homogenizing the aqueous phase and the oil phase with stirring to obtain a homogenized mixed solution; adding 300 to 550 parts of a foaming agent to the homogenized mixed solution and homogenizing the resulting solution with stirring to obtain a homogenized mixed solution containing the foaming agent; reacting the homogenized mixed solution containing the foaming agent with stirring; at the end of the reaction, cooling to room temperature, filtering the resulting suspension to obtain filtrate, centrifuging and dehydrating the filtrate, and drying to obtain the heat-expandable polyvinylidene chloride microsphere product. This disclosure has the advantages of simple process and environmental friendliness, and the obtained product has good performance.

The present disclosure provides natural gas and petrochemical processing systems, including oxidative coupling of methane reactor systems that may integrate process inputs and outputs to cooperatively utilize different inputs and outputs in the production of higher hydrocarbons from natural gas and other hydrocarbon feedstocks. The present disclosure also provides apparatuses and methods for heat exchange, such as an apparatus that can perform boiling and steam super-heating in separate chambers in order to reach a target outlet temperature that is relatively constant as the apparatus becomes fouled. A system of the present disclosure may include an oxidative coupling of methane (OCM) subsystem that generates a product stream comprising compounds with two or more carbon atoms, and a dual compartment heat exchanger downstream of, and fluidically coupled to, the OCM subsystem.

The present disclosure relates to compositions comprising a copolymer derived from a vinyl aromatic monomer, a (meth)acrylate monomer, an acid monomer, and a copolymerizable surfactant and compositions comprising the same. The (meth)acrylate monomer can be selected from a monomer having a theoretical glass transition temperature (Tg) for its corresponding homopolymer of 0° C. or less or a hydrophobic (meth)acrylate monomer. In some embodiments, the copolymer is further derived from an organosilane. The copolymers can have a theoretical glass transition temperature (Tg) from −60° C. to 80° C. and a number average particle size of 250 nm or less. The compositions can be used to prepare compositions such as coatings that have improved water resistance, blush resistance, and/or resistance to hydrostatic pressures. Methods of making the copolymers are also provided.

The present invention relates to a vinyl chloride polymer and a production method thereof. More specifically, the present invention provides a vinyl chloride polymer having a polydispersity index of 2.0 to 2.3 and a porosity of 60% or greater and a production method thereof in which a vinyl chloride polymerization seed having a conversion rate of 5-20% is first prepared through preliminary polymerization and then a vinyl chloride monomer is introduced into the vinyl chloride polymerization seed to polymerize (main polymerization) a vinyl chloride polymer.