A preparation method of a high-rate foamed polylactic acid (PLA) sheet includes first-stage extrusion, second-stage extrusion, and foamed sheet extrusion. The method requires the following raw materials in parts by mass: 88 to 94 parts of PLA, 1 to 2 parts of a nucleating agent, 2 to 5 parts of a foaming agent, and 2 to 5 parts of an additive. The new method effectively solves the problems of low foaming rate, low strength, and the like in the industrial production using carbon dioxide, and a prepared PLA sheet with high foaming rate and excellent surface performance can be used in the fields of food packaging, disposable fully-degradable lunch boxes, and the like.

A method for directly preparing a foamed polylactic acid (PLA) product from a PLA melt includes PLA melt preparation, feeding, and two-stage extrusion. In the two-stage extrusion, a pressure at an outlet of a first-stage twin-screw extruder is 15 MPa to 17 MPa, a PLA melt is fed at a rate of 250 kg/h, a foaming additive is fed at a rate of 7.5 kg/h to 10 kg/h, and a foaming gas is fed at a rate of 2.8 L/h to 7.5 L/h. The method can ensure both foamability and quality of a material and reduce more than ⅓ of energy consumption; and an obtained product has an adjustable foaming rate of 3 to 25, a crystallinity of 40.3% to 48.5%, a tensile strength of 8.7 MPa to 19.6 MPa, and an apparent density of 0.05 g/cm.sup.3 to 0.4 g/cm.sup.3.

The present disclosure relates to an expanded foam solution for forming a thermosetting expanded foam having excellent flame retardancy produced using the same. According to the present disclosure, nanoclay is mixed with a polyol-based compound using ultrasonic waves, an isocyanate-based compound is added, and a trimerization catalyst or an isocyanurate compound is mixed with the polyol-based compound so that an isocyanurate structure is formed.

A method of applying a closed cell spray foam insulation may include spraying a first layer of a closed cell spray foam insulation into a wall cavity. A B-side mixture of the closed cell spray foam insulation may include a polyol blend having a polyester polyol having a functionality of at least about 3.0 and a polyether polyol. The method may include spraying at least one additional layer of the closed cell spray foam insulation against the first layer within 5 minutes of spraying the first layer.

Embodiments of the present disclosure are directed towards hybrid foam formulations that include: an isocyanate-reactive composition, and a high-functionality crosslinker; an azo type radical initiator; and an isocyanate.

A thermoset foam comprises from 0.2 to 4.0 wt. % of at least one aliphatic brominated polyether polyol, from 2.0 to 7.0 wt. % of at least one aromatic brominated polyester polyol, and from 2.0 to 7.5 wt. % of at least one flame retardant comprising organo-phosphate, organo-phosphonate, or organo-phosphite, wherein the ratio of the amount of aliphatic bromine expressed as a percentage of total bromine to the amount of aromatic bromine expressed as a percentage of total bromine is from 10:90 to 50:50.

A method of producing a closed-cell and rigid foam. The method comprises reacting an isocyanate composition including one or more polyisocyanates and a polyol composition including one or more polyols including one or more aromatic polyester polyols having a hydroxyl functionality of greater than 2 and one or more physical and/or chemical blowing agents including methylal to form a closed-cell and rigid foam configured to retain at least 85% of an initial volume of the closed-cell and rigid foam when exposed to about 97% relative humidity at about 70° C. for at least seven or more days.

The invention relates to a non-cross-linked copolymer foam with polyamide blocks and polyether blocks, wherein: the polyamide blocks of the copolymer have an average molar mass of from 200 to 1,500 g/mol; the polyether blocks of the copolymer have an average molar mass of from 800 to 2,500 g/mol; and the weight ratio of the polyamide blocks to the polyether blocks of the copolymer is from 0.1 to 0.9. The invention also relates to a method for manufacturing said foam and items manufactured from said foam.

The invention provides polyurethane and polyisocyanurate foams and methods for the preparation thereof. More particularly, the invention relates to open-celled, polyurethane and polyisocyanurate foams and methods for their preparation. The foams are characterized by a fine uniform cell structure and little or no foam collapse. The foams are produced with a polyol premix composition which comprises a combination of a hydrohaloolefin blowing agent, a polyol, a silicone surfactant, and a sterically hindered amine catalyst.

A synthetic resin formulation can be made using a styrenic polymer created via the depolymerization of a polystyrene feedstock. In some embodiments the polystyrene feedstock contains recycled polystyrene foam. In some embodiments, the styrenic polymer has a molecular weight similar to virgin polystyrene. In some embodiments, the styrenic polymer has a higher molecular weight and reduces the amount of virgin polystyrene needed for a synthetic resin formulation. In some embodiments, the styrenic polymer has a lower molecular weight and increases the amount of recycled polystyrene that can be used in a synthetic resin formulation by increasing and homogenizing the melt flow of the recycled polystyrene. The synthetic resin formulation can be used to make expanded, extruded, and/or graphite polystyrene foam products, as well as rigid polystyrene and ABS products.