LIGNIN-COMPRISING POLYURETHANE MATERIALS AND METHODS FOR THEIR PRODUCTION

Abstract

A polyurethane material comprising the reaction product of a polyol, lignin, a catalyst, and a polyisocyanate. The polyol comprises an amphiphilic polyoxyalkylene copolymer having at least two terminal primary or secondary hydroxyl groups. The amphiphilic polyoxyalkylene copolymer comprises hydrophilic oxyalkylene groups covalently bonded to hydrophobic oxyalkylene groups. The polyurethane material may be a polyurethane foam, and the lignin may comprise more than 30% by weight of the polyurethane foam.

Description

INTRODUCTION

[0001] The information contained in this section is intended to provide a general context for the disclosure. Work by the presently named inventors, to the extent described in this introduction, as well as aspects of the description that might not otherwise be considered prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against this disclosure.

[0002] The present disclosure relates to high lignin polyurethane materials and methods for producing such polyurethane materials.

[0003] Lignin is a natural polyol and a promising candidate for use as a polyol in the production of polyurethane materials because it is abundant in nature and is a by-product of various manufacturing processes. SUMMARY OF THE INVENTION

[0004] A polyurethane material according to one or more embodiments of the present disclosure comprises the reaction product of a polyol, lignin, a catalyst, and a polyisocyanate. The polyol comprises an amphiphilic polyoxyalkylene copolymer having at least two terminal primary or secondary hydroxyl groups. The amphiphilic polyoxyalkylene copolymer comprises hydrophilic oxyalkylene groups covalently bonded to hydrophobic oxyalkylene groups.

[0005] The lignin may be a particulate material with an average particle diameter of greater than or equal to 5 micrometers and less than or equal to 250 micrometers.

[0006] The lignin can make up more than 30% by weight of the polyurethane material. The lignin can be homogeneously distributed throughout the polyurethane material.

[0007] The lignin can be a natural plant product, kraft lignin, soda lignin, organosolv lignin, sulfite lignin, lignocellulosic biomass, or a combination thereof. The lignin must not have been subjected to oxypropylation, chemical grafting, heat treatment, hydrolysis, microwave irradiation, or a combination thereof.

[0008] The amphiphilic polyoxyalkylene copolymer may comprise a copolymer of oxyethylene and oxypropylene.

[0009] In some embodiments, the polyol may comprise a first amphiphilic polyoxyalkylene copolymer having a functionality of greater than or equal to 2 and less than or equal to 10, a nominal molecular weight of greater than or equal to 100 Daltons and less than or equal to 10,000 Daltons, and a hydroxyl value of greater than or equal to 10 milligrams of potassium hydroxide per gram and less than or equal to 400 milligrams of potassium hydroxide per gram.

[0010] In some embodiments, the polyol may comprise a first amphiphilic polyoxyalkylene copolymer and a second amphiphilic polyoxyalkylene copolymer. The first amphiphilic polyoxyalkylene copolymer may have a functionality of greater than or equal to 2 and less than or equal to 3, a nominal molecular weight of greater than or equal to 6,000 Daltons and less than or equal to 7,000 Daltons, and a hydroxyl value of greater than or equal to 20 milligrams of potassium hydroxide per gram and less than or equal to 30 milligrams of potassium hydroxide per gram. The second amphiphilic polyoxyalkylene copolymer may have a functionality of greater than or equal to 4 and less than or equal to 6, a nominal molecular weight of greater than or equal to 180 Daltons and less than or equal to 1,000 Daltons, and a hydroxyl value of greater than or equal to 200 milligrams of potassium hydroxide per gram and less than or equal to 400 milligrams of potassium hydroxide per gram.

[0011] In some embodiments, the polyol may be a polyoxyalkylene copolymer of the formula R-[(OA 1 )a (OA 2 ) b (OA') c -OH] x wherein R is a cyclic or acyclic aliphatic hydrocarbon group, AO 1 and AO 3 Oxyethylene are, AO 2 Oxypropylene, a, b and c are integers, a+b+c is greater than / equal to 3 and less than / equal to 300 and x is an integer greater than / equal to 2 and less than / equal to 6.

[0012] In this case, in some embodiments, the polyoxyalkylene copolymer may be a block copolymer, and a, b, and c may each be integers greater than or equal to 2.

[0013] The polyisocyanate may include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polyphenylene polymethylene polyisocyanate, hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), or a combination thereof.

[0014] The catalyst may comprise a metal-containing catalyst and a tertiary amine catalyst.

[0015] The polyurethane material may further comprise a surfactant comprising a silicone-containing material.

[0016] The polyurethane material may further comprise a crosslinker comprising a polyol having a molecular weight of greater than or equal to 50 grams per mole and less than or equal to 300 grams per mole.

[0017] The polyurethane material may further comprise an additive comprising a flame retardant, a viscosity modifier, an antimicrobial agent, a pigment, a fragrance, an antioxidant, a UV light stabilizer, or a combination thereof.

[0018] The polyurethane material may also comprise a blowing agent.

[0019] The polyurethane material may be a polyurethane foam with a density of greater than or equal to 40 kilograms per cubic meter and less than or equal to 400 kilograms per cubic meter and a compressive force deformation of greater than or equal to 4 kilopascals and less than or equal to 800 kilopascals.

[0020] A polyurethane foam according to one or more embodiments of the present disclosure comprises the reaction product of a polyol, lignin, a surfactant, a catalyst, and a polyisocyanate. The polyol comprises a copolymer of oxyethylene and oxypropylene. The copolymer has at least two terminal primary or secondary hydroxyl groups. The lignin is homogeneously distributed throughout the polyurethane foam and constitutes greater than or equal to 30 wt.% of the polyurethane foam. The polyurethane foam has a density of greater than or equal to 40 kilograms per cubic meter and less than or equal to 400 kilograms per cubic meter and a compressive force deflection of greater than or equal to 4 kilopascals and less than or equal to 800 kilopascals.

[0021] The lignin may be a natural plant product, kraft lignin, soda lignin, organosolv lignin, sulfite lignin, lignocellulosic biomass, or a combination thereof. The lignin must not have undergone oxypropylation, chemical grafting, heat treatment, hydrolysis, microwave irradiation, or a combination thereof. The lignin may be a particulate material with a mean particle diameter of greater than or equal to 5 micrometers and less than or equal to 250 micrometers.

[0022] The copolymer has a functionality of greater than or equal to 2 and less than or equal to 6, a nominal molecular weight of greater than or equal to 100 Daltons and less than or equal to 10,000 Daltons, and a hydroxyl value of greater than or equal to 10 milligrams of potassium hydroxide per gram and less than or equal to 400 milligrams of potassium hydroxide per gram.

[0023] A method for producing a polyurethane material according to one or more embodiments of the present disclosure comprises mixing a polyol and lignin at a speed of greater than or equal to 200 revolutions per minute and less than or equal to 10,000 revolutions per minute for a duration of less than or equal to 1 hour to form a polyol mixture. The mass ratio of lignin to polyol (lignin:polyol) in the polyol mixture is greater than 3:7 and less than or equal to 9:1. A catalyst is introduced into the polyol mixture to form an intermediate mixture. A polyisocyanate is introduced into the intermediate mixture to form the polyurethane material.

[0024] Further areas of applicability of the present disclosure will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are for illustrative purposes only and are not intended to limit the scope of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present disclosure will be better understood from the detailed description and the accompanying drawings, in which: Fig. 1 a schematic representation of a motor vehicle comprising a polyurethane material.

[0026] Reference symbols may be reused in the drawings to identify similar and / or identical elements. DETAILED DESCRIPTION

[0027] The present disclosure relates to polyurethane materials with unmodified lignin and to methods for producing such polyurethane materials. A polyurethane material produced according to one or more embodiments of the present disclosure may be a polyurethane foam (e.g., an integral skin foam), a polyurethane adhesive, a polyurethane elastomer, a polyurethane coating, or polyurethane fibers. In some embodiments where the polyurethane material comprises a polyurethane foam, the polyurethane foam may be a flexible foam, a semi-rigid foam, or a rigid foam. Referring to Fig.1, the polyurethane material may, in some embodiments, be a component of a motor vehicle 10. Motor vehicle components that may be formed from and / or include the polyurethane materials presented herein include luggage racks, crash pads (e.g., instrument panels, knee bolsters, and / or door panels), vehicle seats, headrests, armrests, consoles, headliners, steering wheels, instrument panels, impact plates, cargo areas, and cargo and storage compartments.

[0028] In some embodiments where the polyurethane material is a polyurethane foam, the polyurethane foam may have a density of greater than or equal to 40 kilograms per cubic meter (kg / m 3 ), optionally greater than or equal to 50 kg / m 3 , optionally greater than or equal to 100 kg / m 3 , optionally greater than or equal to 150 kg / m 3 , optionally greater than or equal to 170 kg / m 3 , optionally greater than or equal to 180 kg / m 3 , optionally greater than or equal to 200 kg / m 3or optionally greater than or equal to 215 kg / m 3 , and less than or equal to 400 kg / m 3 , optionally less than or equal to 300 kg / m 3 or optionally less than or equal to 250 kg / m 3 Furthermore, in some embodiments where the polyurethane material is a polyurethane foam, the polyurethane foam can have a compressive force deflection measured according to ASTM D1621 using a 25% deflection value at ambient temperature (e.g., a temperature of about 25 degrees Celsius, °C) of greater than or equal to 45 kilopascals (kPa), optionally greater than or equal to 100 kPa, optionally greater than or equal to 120 kPa, optionally greater than or equal to 130 kPa, optionally greater than or equal to 200 kPa, optionally greater than or equal to 250 kPa, optionally greater than or equal to 300 kPa, optionally greater than or equal to 400 kPa, optionally greater than or equal to 500 kPa, or optionally greater than or equal to 600 kPa, and less than or equal to 1500 kPa, optionally less than or equal to 1000 kPa, or optionally less than or equal to 800 kPa.

[0029] A polyurethane material according to one or more embodiments of the present disclosure comprises the reaction product of a polyol, lignin, a polyisocyanate, a catalyst, optionally a surfactant, optionally a crosslinker, optionally a blowing agent, and optionally an additive. The polyurethane material can be prepared by forming a reaction mixture comprising the polyol, the lignin, the polyisocyanate, the catalyst, the optional surfactant, the optional crosslinker, the optional blowing agent, and the optional additive. The polyol and lignin components can together form the isocyanate-reactive component or resin component of the reaction mixture. The amount of each individual component in the reaction mixture can be specified relative to the amount of the resin component in the reaction mixture. For example, the amount of each component in the reaction mixture can be specified in parts by weight per hundred resin units (PHR).

[0030] The polyol is formulated to ensure a uniform and homogeneous dispersion of lignin in the reaction mixture used to produce the polyurethane material, thus effectively eliminating the need for aggressive mechanical mixing (e.g., ball milling) of the reaction mixture and / or the need to chemically, thermally, or otherwise modify the lignin prior to producing the polyurethane material. The polyol used to produce the polyurethane materials described herein effectively enables the production of polyurethane materials with a relatively high lignin content (e.g., greater than 30 wt%), as well as a substantially uniform physical appearance and substantially homogeneous chemical composition.Since the polyol allows the lignin to be readily and homogeneously dispersed throughout the polyurethane material throughout the manufacturing process without aggressive mechanical mixing and without prior chemical and / or thermal treatment, the polyol can be used to effectively and consistently produce polyurethane materials with high lignin content and high reproducibility, requiring less time and less energy than other manufacturing processes.

[0031] The polyol comprises at least one amphiphilic polyoxyalkylene copolymer having at least two terminal primary or secondary hydroxyl groups and hydrophilic oxyalkylene groups (e.g., oxyethylene groups) covalently bonded to hydrophobic oxyalkylene groups (e.g., oxypropylene groups). In some embodiments, the polyol may comprise at least one amphiphilic polyoxyalkylene copolymer having at least two terminal primary hydroxyl groups. The hydrophilic oxyalkylene groups and the hydrophobic oxyalkylene groups may be randomly distributed along the polyol chain, or the hydrophilic oxyalkylene groups and the hydrophobic oxyalkylene groups may be arranged in specific blocks. Primary hydroxyl groups (-OH) are directly bonded to primary carbon atoms, which are directly bonded to a single carbon atom, while secondary hydroxyl groups are directly bonded to secondary carbon atoms, which are directly bonded to two carbon atoms.

[0032] The polyol may be at least one polyoxyalkylene copolymer of formula (1) R−[(OA1)a(OA2)b(OA3)c−OH]x, wherein R is a polyvalent aliphatic hydrocarbon AO 1 is, AO 2 and AO 3 are each individually oxyalkylene groups, a and b are integers, c is zero or an integer, a+b+c is greater than / equal to 3 and less than / equal to 300, and x is an integer greater than / equal to 2. In some embodiments, x can be greater than / equal to 3, optionally greater than / equal to 4, optionally greater than / equal to 6, or optionally greater than / equal to 8, and less than / equal to 10.

[0033] R can be a cyclic or acyclic aliphatic hydrocarbon group having 2 to 10 carbon atoms and 2 or more bonding sites. For example, the number of bonding sites on the R group in the polyoxyalkylene copolymer of formula (1) can be greater than or equal to 2, optionally greater than or equal to 3, optionally greater than or equal to 4, optionally greater than or equal to 6, or optionally greater than or equal to 8, and less than or equal to 10. Exemplary aliphatic hydrocarbon groups with 2 bonding sites are ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, cyclopentylene, and cyclohexylene. Further exemplary aliphatic hydrocarbon groups with 3 to 6 bonding sites are residues which are each obtained by removing a hydroxyl group from a polyhydric alcohol, such as trimethylolpropane, glycerol, pentaerythritol, sorbitol, 1,2,3-trihydroxycyclohexane or 1,3,5-trihydroxycyclohexane.

[0034] The value of x in the polyoxyalkylene copolymer of formula (1) directly corresponds to the number of bonding sites on the R group. For example, if R has 2 bonding sites, the value of x is 2. Furthermore, the value of x corresponds to the number of isocyanate-reactive functional groups (i.e., hydroxyl groups) in the polyoxyalkylene copolymer of formula (1), which may be referred to as the "functionality" of the polyol and / or the polyoxyalkylene copolymer of formula (1). In some embodiments, the polyol may have a functionality of greater than or equal to 2, optionally greater than or equal to 3, optionally greater than or equal to 4, optionally greater than or equal to 6, or optionally greater than or equal to 8, and less than or equal to 10.

[0035] In the polyoxyalkylene copolymer of formula (1), the oxyalkylene groups (AO 1 , AO 2 and AO 3 ) each individually the formula -OR 1 -, where R 1 is a linear or branched divalent hydrocarbon group, and where AO2 by AO 1 and AO 3 Examples of linear or branched-chain divalent hydrocarbon radicals are ethylene, propylene, butylene, pentylene, isopropylene, hexylene, heptylene, octylene, nonylene, decylene, cyclopentylene, and cyclohexylene. Each of the oxyalkylene groups (AO 1 , AO 2 and AO 3 ) can be hydrophilic or hydrophobic. In some embodiments, at least one of the oxyalkylene groups is a hydrophilic group (e.g., oxyethylene) and at least one of the oxyalkylene groups is a hydrophobic group (e.g., oxypropylene). In some embodiments, AO 1 a hydrophilic oxyalkylene group, AO 2 a hydrophobic oxyalkylene group and, if present, AO 3 a hydrophilic oxyalkylene group. If c is an integer greater than or equal to 1 and AO 3a hydrophilic oxyalkylene group, the polyoxyalkylene copolymer of formula (1) may be referred to as a polyoxyalkylene copolymer with a hydrophilic endcap. In some embodiments, the polyol may be a block copolymer. In that case, in the polyoxyalkylene copolymer of formula (1), a is an integer greater than or equal to 2, b is an integer greater than or equal to 2, and c (if present) is an integer greater than or equal to 2.

[0036] The amphiphilic polyoxyalkylene copolymer may have a nominal molecular weight of greater than or equal to 100 Daltons, optionally greater than or equal to 500 Daltons, optionally greater than or equal to 2000 Daltons, optionally greater than or equal to 3000 Daltons, optionally greater than or equal to 4000 Daltons, optionally greater than or equal to 5000 Daltons, or optionally greater than or equal to 6000 Daltons, and less than or equal to 10,000 Daltons. The hydroxyl value of the polyol is defined as the number of milligrams (mg) of potassium hydroxide (KOH) required to neutralize the acetic acid absorbed during acetylation by one gram (g) of the polyol. The polyol may have a hydroxyl value of greater than or equal to 10 mg KOH / g, optionally greater than or equal to 20 mg KOH / g, and less than or equal to 400 mg KOH / g, optionally less than or equal to 350 mg KOH / g or optionally less than or equal to 30 mg KOH / g.The polyol may have a viscosity at 77 degrees Fahrenheit (°F) of greater than or equal to 1000 centipoise (cP), optionally greater than or equal to 1200 cP, optionally greater than or equal to 1300 cP, and less than or equal to 2500 cP, or optionally less than or equal to 1500 cP.

[0037] The polyol may be present in the reaction mixture used to form the polyurethane material in a mass fraction of greater than or equal to 10 parts PHR, optionally greater than or equal to 20 PHR, optionally greater than or equal to 30 PHR, optionally greater than or equal to 40 PHR or optionally greater than or equal to 50 PHR, and less than or equal to 70 PHR.

[0038] In some embodiments, the polyol may comprise a first and a second polyol. The first polyol and / or the second polyol may comprise at least one amphiphilic polyoxyalkylene copolymer comprising hydrophilic oxyalkylene groups covalently bonded to hydrophobic oxyalkylene groups. In some embodiments, the first polyol and / or the second polyol may comprise a copolymer of oxyethylene and oxypropylene. The functionality of the first polyol may be less than that of the second polyol. For example, the first polyol may have a functionality of 3 and the second polyol may have a functionality of 4. Furthermore, the hydroxyl value of the first polyol may be less than that of the second polyol. For example, the first polyol may have a hydroxyl value of greater than or equal to 20 mg KOH / g and less than or equal to 30 mg KOH / g, and the second polyol may have a hydroxyl value of greater than or equal to 200 mg KOH / g and less than or equal to 400 mg KOH / g.The nominal molecular weight of the first polyol may be greater than that of the second polyol. For example, the first polyol may have a nominal molecular weight of greater than or equal to 6000 Daltons and less than or equal to 7000 Daltons (e.g., about 6500 Daltons), and the second polyol may have a nominal molecular weight of greater than or equal to 150 Daltons and less than or equal to 1000 Daltons (e.g., about 740 Daltons). The viscosity of the first polyol may be lower than that of the second polyol. For example, the first polyol may have a viscosity at 77°F of greater than or equal to 1 centipoise (cP) or optionally greater than or equal to 1200 cP and less than or equal to 1500 cP (e.g., about 1370 cP) and the second polyol may have a viscosity at 77°F of greater than or equal to 1600 cP and less than or equal to 2000 cP (e.g., about 1800 cP).In some embodiments where the polyol comprises a first polyol and a second polyol, the first polyol and the second polyol may each be individually present in the reaction mixture used to form the polyurethane material in a mass fraction of greater than or equal to 1 PHR, optionally greater than or equal to 5 PHR, optionally greater than or equal to 10 PHR, optionally greater than or equal to 20 PHR, optionally greater than or equal to 30 PHR, optionally greater than or equal to 40 PHR, or optionally greater than or equal to 50 PHR, and less than or equal to 69 PHR or optionally less than or equal to 60 PHR.

[0039] The lignin is formulated to impart suitable stiffness to the polyurethane material while minimizing the amount of polyol required in the reaction mixture to achieve this stiffness. The lignin can be a natural product (e.g., natural hardwood, softwood, bamboo, and / or another natural plant product) and / or a by-product of one or more manufacturing processes, including biorefinery processes and various chemical pulping processes such as kraft pulping, soda pulping, organosolv pulping, and / or sulfite pulping, which may be used in papermaking. The lignin can be unmodified, meaning it must not be chemically modified, functionalized, and / or heat-treated after being obtained as a natural product or as a by-product of a manufacturing process, e.g., a biorefinery or chemical pulping process.For example, the lignin must not have undergone oxypropylation, chemical grafting (e.g., grafting with polyethylene glycol), heat treatment, hydrolysis, and / or microwave liquefaction. In some embodiments, the lignin may comprise unmodified kraft lignin, soda lignin, organosolv lignin, sulfite lignin (also referred to as sulfonate lignin or lignosulfonates), and / or lignocellulosic biomass.

[0040] The lignin may comprise sulfur or be substantially free of sulfur. The lignin may be a particulate material having an average particle diameter of greater than or equal to 5 micrometers (µm), optionally greater than or equal to 10 µm, optionally greater than or equal to 15 µm, and less than or equal to 500 µm, optionally less than or equal to 250 µm, optionally less than or equal to 150 µm, optionally less than or equal to 110 µm, optionally less than or equal to 100 µm, optionally less than or equal to 95 µm, optionally less than or equal to 90 µm, or optionally less than or equal to 25 µm. In some embodiments, the lignin may have an average particle diameter of greater than or equal to 5 µm and less than or equal to 25 µm, or optionally greater than or equal to 5 µm and less than or equal to 15 µm. The lignin can be subjected to a milling process (e.g., a jet milling process) to achieve a desired average particle diameter.

[0041] The lignin can be present in the reaction mixture used to form the polyurethane material in a mass fraction of greater than or equal to 30 PHR, optionally greater than or equal to 40 PHR, optionally greater than or equal to 50 PHR, optionally greater than or equal to 60 PHR, optionally greater than or equal to 70 PHR, or optionally greater than or equal to 80 PHR, and less than or equal to 90 PHR. The lignin can constitute greater than or equal to 30 wt%, optionally greater than or equal to 40 wt%, optionally greater than or equal to 50 wt%, optionally greater than or equal to 60 wt%, optionally greater than or equal to 70 wt%, optionally greater than or equal to 80 wt%, and less than or equal to 90 wt% of the polyurethane material.

[0042] The polyisocyanate is a polyfunctional isocyanate comprising at least two isocyanate groups (-N=C=O groups or NCO groups). The polyisocyanate may comprise, for example, a diisocyanate, a triisocyanate, a tetraisocyanate, etc. The isocyanate groups in the polyisocyanate are formulated to react with the hydroxyl groups of the polyol and / or lignin to form urethane bonds (-NH-(C=O)-O-) between them, thereby forming the polyurethane material. Examples of polyisocyanates include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), mixtures of diphenylmethane diisocyanate and polyphenylene polymethylene polyisocyanates (crude MDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), and combinations thereof.

[0043] The polyol, the lignin, and the optional crosslinker each comprise isocyanate-reactive groups, i.e., hydroxyl groups (or -OH groups). The isocyanate index of the reaction mixture used to prepare the polyurethane material is, as known in the art, the ratio of the total number of isocyanate groups in the polyisocyanate to the total number of isocyanate-reactive groups in the reaction mixture (i.e., in the polyol, the lignin, and the optional crosslinker), multiplied by 100. The polyisocyanate may be present in the reaction mixture used to form the polyurethane material in an amount such that the isocyanate index of the reaction mixture is greater than or equal to 50, optionally greater than or equal to 75, or optionally greater than or equal to 100, and less than or equal to 150, optionally less than or equal to 125, or optionally less than or equal to 110.The amount of polyisocyanate in the reaction mixture used to produce the polyurethane material can be selected to give the polyurethane material the desired density and / or stiffness.

[0044] The catalyst is formulated to accelerate the reactions and formation of covalent bonds between the polyol, the lignin, and the polyisocyanate, thereby accelerating the formation of the polyurethane material. In some embodiments, where the reaction mixture used to form the polyurethane material comprises the optional blowing agent and the polyurethane material is a polyurethane foam, the catalyst can be formulated to accelerate the reaction between the polyisocyanate and the blowing agent (e.g., water) to generate gas bubbles (e.g., CO2 bubbles) in the polyurethane material. The catalyst comprises a metal catalyst and an amine catalyst. The metal catalyst can comprise an organic metal-containing catalyst, such as mercury, lead, tin, bismuth, potassium, zinc, or a combination thereof. Exemplary metal catalysts are dibutyltin dilaurate, stannous octoate, potassium octoate, and combinations thereof.In some embodiments, the metal catalyst comprises dibutyltin dilaurate. The metal catalyst may be present in the reaction mixture used to form the polyurethane material in a mass fraction of greater than or equal to 0.5 PHR, optionally greater than or equal to 1 PHR, or optionally greater than or equal to 1.5 PHR, and less than or equal to 4 PHR, optionally less than or equal to 3 PHR, or optionally less than or equal to 2 PHR. The amine catalyst may comprise a tertiary amine. Exemplary tertiary amine catalysts are diethylenetriamine (DETA), dimethylcyclohexylamine (DMCHA), dimethylethanolamine (DMEA), triethanolamine (TEA), and combinations thereof. The amine catalyst may be present in the reaction mixture used to form the polyurethane material in a mass fraction of greater than or equal to 0.1 PHR, optionally greater than or equal to 0.3 PHR or optionally greater than or equal to 0.5 PHR, and less than or equal to 2 PHR or optionally less than or equal to 1 PHR.

[0045] The optional surfactant can contribute to stabilizing the physical structure of the polyurethane material. Examples of surfactants are silicone-containing substances, e.g., polyether siloxanes. If present, the surfactant can be present in the reaction mixture used to form the polyurethane material in a mass fraction of greater than or equal to 0.5 PHR, optionally greater than or equal to 1 PHR, or optionally greater than or equal to 1.5 PHR, and less than or equal to 6 PHR, optionally less than or equal to 5 PHR, or optionally less than or equal to 4 PHR.

[0046] The optional crosslinker can help stabilize the polyurethane material and form crosslinks within the polyurethane material, thereby increasing the stiffness of the material. Examples of crosslinkers include diols and polyols with a molecular weight of greater than or equal to 50 grams per mole (g / mol) and less than or equal to 300 g / mol. Examples of crosslinkers include low molecular weight diols, polyols, and / or polyamines, including glycerin, glycerol, glycerol propoxylate, diethanolamine (DEA), triethanolamine (TEA), trimethylolpropane, ethylene glycol, propylene glycol, dimethylthiotoluenediamine (DMTDA), 1,4-butanediol, diethyltoluenediamine (DETDA), and combinations thereof. If present, the optional crosslinker may be present in the reaction mixture used to form the polyurethane material in a mass fraction of greater than or equal to 1 PHR, optionally greater than or equal to 3 PHR, or optionally greater than or equal to 5 PHR, and less than 10 PHR or optionally less than or equal to 7 PHR.

[0047] In some embodiments, the reaction mixture used to form the polyurethane material may comprise less than 10 PHR, or optionally less than 7 PHR, or optionally less than 5 PHR of diols, polyols, and / or polyamines having a molecular weight of less than or equal to 300 g / mol.

[0048] The optional blowing agent may be included in some embodiments where the polyurethane material comprises a polyurethane foam. In that case, the optional blowing agent may serve to form or contribute to the formation of gas bubbles in the polyurethane material. The blowing agent may be a chemical blowing agent that reacts with one or more components in the reaction mixture (e.g., the polyisocyanate) to form gas bubbles, or a physical blowing agent that itself forms gas bubbles in the polyurethane material. An exemplary chemical blowing agent is water. Exemplary physical blowing agents are gases (e.g., liquefied carbon dioxide), volatile liquids with boiling points of less than or equal to 75 degrees Celsius (°C), optionally less than or equal to 60°C, or optionally less than or equal to 50°C, and combinations thereof.Examples of volatile liquids that can be used as physical blowing agents are hydrocarbons having 4 or 5 carbon atoms (e.g., cyclo-, iso-, and / or n-pentane, fluorocarbons, chlorofluorocarbons), oxygen-containing compounds (e.g., methyl formate and / or dimethoxymethane), chlorinated hydrocarbons (e.g., dichloromethane and / or 1,2-dichloroethane), ketones (e.g., acetone), aldehydes (e.g., methylal), and combinations thereof. When present, the optional blowing agent can be present in the reaction mixture used to form the polyurethane material in a mass fraction of greater than or equal to 0.1 PHR, optionally greater than or equal to 0.5 PHR, or optionally greater than or equal to 1 PHR, and less than 5 PHR, or optionally less than or equal to 2 PHR.

[0049] The optional additive may be included to impart certain desired properties to the polyurethane material. In some embodiments, the optional additive may include a flame retardant, a viscosity modifier, an antimicrobial agent, a pigment, a fragrance, an oxidative degradation stabilizer (an antioxidant), a UV light stabilizer, or a combination thereof. Exemplary flame retardants include lignosulfonate-based compounds, phosphorus-containing compounds, bromine-containing compounds, polyamide-based compounds, polyetherimide-based compounds, aluminum-containing compounds, magnesium-containing compounds, and combinations thereof. Exemplary viscosity modifiers include dibasic esters.If present, the optional additive may be present in the reaction mixture used to form the polyurethane material in a mass fraction of greater than or equal to 1 PHR, optionally greater than or equal to 2 PHR, optionally greater than or equal to 5 PHR, or optionally greater than or equal to 10 PHR and less than 25 PHR, or optionally less than or equal to 15 PHR. Proceedings

[0050] The polyurethane material can be prepared by forming a reaction mixture comprising the polyol, the lignin, the polyisocyanate, the catalyst, the optional surfactant, the optional crosslinker, the optional blowing agent, and the optional additive. The reaction mixture can be formed as follows: (i) forming a polyol mixture comprising the polyol and the lignin, (ii) introducing the catalyst and the optional blowing agent into the polyol mixture to form an intermediate mixture, and then (iii) introducing the polyisocyanate into the intermediate mixture to form the polyurethane material. In some embodiments, the polyol mixture can further comprise the optional surfactant, the optional crosslinker, and / or the optional additive, and these components can be introduced into the polyol mixture simultaneously with the polyol and the lignin or subsequently, prior to formation of the intermediate mixture.The mass ratio of lignin to polyol (lignin:polyol) in the polyol mixture can be greater than 3:7 and less than or equal to 9:1.

[0051] The polyol blend is formed by mechanically mixing the polyol and lignin, e.g., using a centrifugal mixer, disperser (e.g., using a disk-shaped blade), or paddle mixer for a period of about 5 minutes to about 1 hour at a speed of about 1000 revolutions per minute (rpm) to about 3000 rpm or about 2000 rpm. After the polyol and lignin are blended together, the polyol blend can be allowed to "swell" for a period of greater than or equal to 1 hour, optionally greater than or equal to 24 hours, or optionally greater than or equal to 1 week, and less than or equal to 2 years. The optional surfactant, the optional crosslinker, and / or the optional additive can be added to the polyol blend before or after swelling. The polyol blend can be mixed at a temperature of greater than or equal to 50°C and less than or equal to 75°C. During the mixing process, heat can be generated in the polyol mixture, e.g.by heat generated due to frictional forces during the mixing process itself, or by external heat input, e.g. by heating the polyol mixture in an oven.

[0052] The intermediate mixture is formed by mechanically mixing the catalyst and optional blowing agent into the polyol mixture, e.g., using a centrifugal mixer, disperser (e.g., using a disk-shaped blade), or paddle mixer for a period of about 30 seconds to about 1 hour at a speed of about 1000 revolutions per minute (rpm) to about 3000 rpm or about 2000 rpm.

[0053] The final reaction mixture is formed by mechanically admixing the polyisocyanate with the intermediate mixture, e.g., using a centrifugal mixer, dispersing device (e.g., using a disk-shaped blade), or paddle mixer for a duration of about 1 second to about 1 minute at a speed of about 1000 revolutions per minute (rpm) to about 3000 rpm or about 2000 rpm. After admixing the polyisocyanate with the intermediate mixture, the reaction mixture can be transferred to a mold or other container where it can cure and solidify to form the polyurethane material. Experimental

[0054] Polyurethane foams were prepared from various reaction mixtures, and the density and compressive force deformation (CFD) of the polyurethane foams were measured. Dibutyltin dilaurate (DBTDL), supplied by Sigma Aldrich, was used as the metal catalyst. Pluracol® 380 and Pluracol® 1168, supplied by BASF, were used as the polyols. VORASURF DC 6070, supplied by DOW, was used as the surfactant. TEGOAMIN® E 10, supplied by Evonik, was used as the tertiary amine catalyst. Mondur MR Light, supplied by Covestro, was used as the polyisocyanate. The lignin was provided by SweetWater Energy Inc. and used as received, except that it was jet-milled to an average particle diameter of 10 µm. The Max 100 Long FlackTek cups were purchased from Fischer Scientific.As published by BASF Corporation, Pluracol® 380 has a nominal functionality of 3, a hydroxyl value of 24.0-26.0 mg KOH / g, a nominal molecular weight of 6500 Daltons, a viscosity of 1370 cP at 77 degrees Fahrenheit (°F), and a maximum of 0.05 wt% water. Pluracol® 1168 has a nominal functionality of 4, a hydroxyl value of 285-315 mg KOH / g, a nominal molecular weight of 740 Daltons, a viscosity of 1800 cP at 77 degrees Fahrenheit (°F), and a maximum of 0.10 wt% water.

[0055] Density measurements: For Comparative Example 2 and Examples 3 to 6: A rectangular block measuring approximately 25 mm high x 50 mm wide x 50 mm long was cut from the cured main foam block. The actual dimensions were confirmed using digital calipers for each individual foam sample. For Comparative Example 1: A cross-section approximately 10 mm thick was cut from the cured main foam block. After cutting, a 30 mm diameter disc was punched out of the 10 mm thick cross-section using a 30 mm punch, resulting in a cylindrical foam piece measuring approximately 10 mm x 30 mm. The actual dimensions were confirmed using digital calipers for each individual foam sample. The cut foam pieces were then weighed using a laboratory balance so that the individual foam density could be calculated.

[0056] Compressive force deformation measurements (25%): The compressive force deformation tests were conducted according to ASTM D1621 with a deformation value of 25%. The tests were performed on an Instron machine equipped with a stationary rectangular base platform and a movable pressure attachment (purchased from Instron). The foam blocks cut from Comparative Example 1 and Examples 2 to 5, which were used for the density calculations, were used to determine CFD. 25% The samples were compressed to a deformation of 25% and the maximum force was measured. The CFD 25% Values were determined by dividing the maximum force at 25% deformation by the cross-sectional area of the specimen. Comparative example 1: Synthesis of base foam 1

[0057] A polyol mixture comprising Pluracol® 380 (20.0 g, 100 phr) and VORASURF DC 6070 (400 mg, 2 phr) was prepared in a Max 100 Long FlackTek beaker and mixed for 5 minutes at 2000 rpm in a FlackTek mixer. DBTDL (400 mg, 2 phr), Tegoamin® E 10 (100 mg, 0.5 phr), and deionized water (200 mg, 1 phr) were then added to the polyol mixture and mixed with a dispersing disk attached to an overhead stirrer for 1 minute at 2000 rpm to form an intermediate mixture. Mondur MR Light (4.15 g, 1 equivalent in terms of polyol) was added to the intermediate mix in the beaker and mixed with the same overhead stirrer at 2000 rpm for 15 seconds to form a polyurethane foam. The foam was allowed to rest at room temperature for 72 hours before three foam samples were subjected to density measurements. The resulting polyurethane foam had a density of 130 kg / m³. 3 . Comparative example 2: Synthesis of base foam 2

[0058] A polyol mixture comprising Pluracol® 1168 (8.0 g, 100 phr) and VORASURF DC 6070 (120 mg, 1.5 phr) was prepared in a Max 100 Long FlackTek beaker and mixed for 3 minutes at 2000 rpm in a FlackTek mixer. DBTDL (160 mg, 2 phr), Tegoamin® E 10 (40 mg, 0.5 phr), and deionized water (120 mg, 1.5 phr) were then added to the polyol mixture and mixed with a dispersing disk attached to an overhead stirrer for 3 minutes at 2000 rpm to form an intermediate mixture. Mondur MR Light (8.21 g, 1.1 equivalent in terms of polyol) was added to the intermediate mix in the beaker and mixed with the same overhead stirrer at 2000 rpm for 5 seconds to form a polyurethane foam. The foam was allowed to rest at room temperature for at least 72 hours before three foam samples were subjected to density and compression set measurements. The resulting polyurethane foam had a density of 79 kg / m³. 3and a CFD 25% -value of 623 kilopascals (kPa). Example 3: Synthesis of base foam with 50 phr lignin

[0059] A polyol mixture comprising Pluracol® 380 (10.0 g, 50 phr), lignin (10.0 g, 50 phr), and VORASURF DC 6070 (800 mg, 4 phr) was prepared in a Max 100 Long FlackTek cup and mixed for 3 minutes at 2000 rpm in a FlackTek mixer. Subsequently, DBTDL (400 mg, 2 phr) and Tegoamin® E 10 (100 mg, 0.5 phr) were added to the polyol mixture and mixed for 8 minutes at 2000 rpm in a FlackTek mixer to form an intermediate mixture. Immediately after forming the intermediate mix, Mondur MR Light (5.64 g, 0.75 equivalents in terms of polyol) was added to the intermediate mix in the beaker and mixed with the same FlackTek mixer at 2000 rpm for 10 seconds to form a polyurethane foam. The foam was allowed to rest at room temperature for at least 72 hours before three foam samples were subjected to density and compression set measurements. The resulting polyurethane foam had a density of 215±5 kg / m³ 3 and a CFD 25%-value of 140±9 kPa. Example 4: Synthesis of base foam with 50 phr lignin

[0060] A polyol mixture comprising Pluracol® 380 (10.0 g, 50 phr), lignin (10.0 g, 50 phr), and VORASURF DC 6070 (800 mg, 4 phr) was prepared in a Max 100 Long FlackTek cup and mixed for 3 minutes at 2000 rpm in a FlackTek mixer. Subsequently, DBTDL (400 mg, 2 phr) and Tegoamin® E 10 (100 mg, 0.5 phr) were added to the polyol mixture and mixed for 8 minutes at 2000 rpm in a FlackTek mixer to form an intermediate mixture. Immediately after forming the intermediate mix, Mondur MR Light (5.64 g, 1 equivalent in terms of polyol) was added to the intermediate mix in the beaker and mixed with the same FlackTek mixer at 2000 rpm for 10 seconds to form a polyurethane foam. The foam was allowed to rest at room temperature for at least 72 hours before three foam samples were subjected to density and compression set measurements. The resulting polyurethane foam had a density of 173±19 kg / m³. 3 and a CFD 25%-value of 135±1 kPa. Example 5: Synthesis of base foam with 60 phr lignin

[0061] A polyol mixture comprising Pluracol® 380 (8.0 g, 40 phr), lignin (12.0 g, 60 phr), and VORASURF DC 6070 (800 mg, 4 phr) was prepared in a Max 100 Long FlackTek cup and mixed for 3 minutes at 2000 rpm in a FlackTek mixer. Subsequently, DBTDL (400 mg, 2 phr) and Tegoamin® E 10 (100 mg, 0.5 phr) were added to the polyol mixture and mixed for 8 minutes at 2000 rpm in a FlackTek mixer to form an intermediate mixture. Immediately after forming the intermediate mix, Mondur MR Light (5.64 g, 0.75 equivalents in terms of polyol) was added to the intermediate mix in the beaker and mixed with the same FlackTek mixer at 2000 rpm for 10 seconds to form a polyurethane foam. The foam was allowed to rest at room temperature for at least 72 hours before three foam samples were subjected to density and compression set measurements. The resulting polyurethane foam had a density of 216±3 kg / m³ 3 and a CFD 25%-value of 624±54 kPa. Example 6: Synthesis of base foam with 60 phr lignin

[0062] A polyol mixture comprising Pluracol® 380 (8.0 g, 40 phr), lignin (12.0 g, 60 phr), and VORASURF DC 6070 (800 mg, 4 phr) was prepared in a Max 100 Long FlackTek cup and mixed for 3 minutes at 2000 rpm in a FlackTek mixer. Subsequently, DBTDL (400 mg, 2 phr) and Tegoamin® E 10 (100 mg, 0.5 phr) were added to the polyol mixture and mixed for 8 minutes at 2000 rpm in a FlackTek mixer to form an intermediate mixture. Immediately after forming the intermediate mix, Mondur MR Light (5.64 g, 1 equivalent in terms of polyol) was added to the intermediate mix in the beaker and mixed with the same FlackTek mixer at 2000 rpm for 10 seconds to form a polyurethane foam. The foam was allowed to rest at room temperature for at least 72 hours before three foam samples were subjected to density and compression set measurements. The resulting polyurethane foam had a density of 185±15 kg / m³. 3 and a CFD 25%-value of 408±4 kPa. Example 7: Synthesis of base foam with two polyols and 50 phr lignin

[0063] A polyol blend comprising Pluracol® 380 (9.0 g, 45 phr) and Pluracol® 1168 (1.0 g, 5 phr) was prepared in a Max 100 Long FlackTek cup and blended for 2 minutes at 2000 rpm in a FlackTek mixer. Sunburst hydrolysis lignin (10.00 g, 50 phr) and VORASURF-DC-6070 (800 mg, 4 phr) were then added to the polyol blend and mixed again for 3 minutes at 2000 rpm. DBTDL (400 mg, 2 phr) and Tegoamin® E 10 (100 mg, 0.5 phr) were added to the polyol blend and blended for 8 minutes at 2000 rpm in a FlackTek mixer to form an intermediate blend. Immediately after the intermediate mix was formed, Mondur MR Light (8.17 g, 1.0 equivalent in terms of polyol) was added to the intermediate mix in the beaker and mixed with the same FlackTek mixer at 2000 rpm for 10 seconds to form a polyurethane foam.The foam was allowed to rest at room temperature for at least 72 hours before three foam samples were subjected to density and compressive force deformation measurements. The resulting polyurethane foam had a density of 187 kg / m³. 3 and a CFD 25% -value of 323 kPa. Example 8: Synthesis of base foam with crosslinker and 50 phr lignin

[0064] A polyol mixture comprising Pluracol® 380 (10.0 g, 50 phr), Sunburst hydrolysis lignin (10.00 g, 50 phr), diethanolamine (1.0 g, 5 phr), and VORASURF DC 6070 (800 mg, 4 phr) was prepared in a Max 100 Long FlackTek cup and mixed for 3 minutes at 2000 rpm in a FlackTek mixer. Subsequently, DBTDL (400 mg, 2 phr) and Tegoamin® E 10 (100 mg, 0.5 phr) were added to the polyol mixture and mixed for 8 minutes at 2000 rpm in a FlackTek mixer to form an intermediate mixture. Immediately after forming the intermediate mix, Mondur MR Light (10.10 g, 1.0 equivalent in terms of polyol and hydroxyl groups of diethanolamine) was added to the intermediate mix in the beaker and mixed with the same FlackTek mixer at 2000 rpm for 10 seconds to form a polyurethane foam. The foam was allowed to rest at room temperature for at least 72 hours before three foam samples were subjected to density and compressive force deformation measurements.The resulting polyurethane foam had a density of 158 kg / m. 3 and a CFD 25% -value of 267 kPa.

[0065] The foregoing description is merely illustrative and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure may be embodied in a variety of forms. While this disclosure includes specific examples, its true scope should not be limited thereto, since other modifications will become apparent upon review of the drawings, the specification, and the following claims. It is understood that one or more steps within a method may be performed in different orders (or simultaneously) without altering the principles of the present disclosure.Furthermore, although the embodiments are each described above as having specific features, any one or more of these features described with respect to one embodiment of the disclosure may be implemented and / or combined with features of any of the other embodiments, even if such combination is not expressly described. In other words, the described embodiments are not mutually exclusive, and interchanging one or more embodiments for one another remains within the scope of this disclosure.

[0066] The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "a," "an," and "the" are intended to include the plural forms where appropriate. The terms "comprise," "comprising," "including," and "having" are inclusive and thus indicate the presence of stated features, elements, compositions, steps, integers, acts, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, acts, elements, components, and / or groups thereof.Although the open-ended terms "comprises," "comprising," "containing," "including," and "having" are intended to be non-limiting and to describe and claim various embodiments set forth herein, in certain aspects they may alternatively be understood as a more limiting and restrictive term, such as "consisting of" or "consisting essentially of." Therefore, in any embodiment that recites compositions, materials, components, elements, ingredients, features, integers, acts, and / or method steps, the present disclosure expressly includes embodiments consisting of, or consisting essentially of, such recited compositions, materials, components, elements, ingredients, features, integers, acts, and / or method steps.In the case of "consisting of", the alternative embodiment excludes all additional compositions, materials, components, elements, ingredients, features, integers, acts and / or method steps, while in the case of "consisting essentially of", all additional compositions, materials, components, elements, ingredients, features, integers, acts and / or method steps that significantly affect the basic and novel properties are excluded from such embodiment, but all compositions, materials, components, elements, ingredients, features, integers, acts and / or method steps that do not significantly affect the basic and novel properties may be included in the embodiment.

[0067] The phrase "at least one of A, B or C" as used herein should be interpreted as logical (A OR B OR C) using a non-exclusive logical OR operator and should not be understood as "at least one of A, at least one of B and at least one of C".

[0068] The terms "composition" and "material" are used interchangeably herein to generally refer to a substance that contains at least the preferred chemical constituents, elements, or compounds, but which, unless otherwise noted, may also contain additional elements, compounds, or substances, including trace impurities. An "X-based" composition or material generally refers to compositions or materials where "X" is the largest single component by weight (%) of the composition or material. This can include compositions or materials containing more than 50% X and those containing less than 50% X, as long as X is the largest single component of the composition or material by total weight.When a composition or material is described as being “substantially free” of a substance, the composition or material may comprise less than 5% by weight, optionally less than 3% by weight, optionally less than 1% by weight, or optionally less than 0.1% by weight of the substance.

Claims

[1] Polyurethane material comprising the reaction product of: a polyol comprising an amphiphilic polyoxyalkylene copolymer having at least two terminal primary hydroxyl groups, wherein the amphiphilic polyoxyalkylene copolymer comprises hydrophilic oxyalkylene groups covalently bonded to hydrophobic oxyalkylene groups; Lignin; a catalyst; a polyisocyanate; optionally a surfactant comprising a silicone-containing material; optionally a propellant; and optionally an additive comprising a flame retardant, a viscosity modifier, an antimicrobial agent, a pigment, a fragrance, an antioxidant, a UV light stabilizer, or a combination thereof. [2] The polyurethane material of claim 1, wherein the lignin is a particulate material having an average particle diameter of greater than or equal to 5 micrometers and less than or equal to 25 micrometers. [3] Polyurethane material according to claim 1, wherein the lignin constitutes more than 50 wt% of the polyurethane material and wherein the lignin is homogeneously distributed throughout the polyurethane material. [4] The polyurethane material of claim 1, wherein the lignin is a natural plant product, kraft lignin, soda lignin, organosolv lignin, sulfite lignin, lignocellulosic biomass, or a combination thereof, and wherein the lignin has not been subjected to oxypropylation, chemical grafting, heat treatment, hydrolysis, microwave irradiation, or a combination thereof. [5] The polyurethane material of claim 1, wherein the amphiphilic polyoxyalkylene copolymer comprises a copolymer of oxyethylene and oxypropylene. [6] The polyurethane material of claim 1, wherein the polyol comprises a first amphiphilic polyoxyalkylene copolymer having a functionality of greater than or equal to 2 and less than or equal to 3, a nominal molecular weight of greater than or equal to 6000 Daltons and less than or equal to 7000 Daltons, and a hydroxyl value of greater than or equal to 20 milligrams of potassium hydroxide per gram and less than or equal to 30 milligrams of potassium hydroxide per gram. [7] The polyurethane material of claim 6, wherein the polyol further comprises a second amphiphilic polyoxyalkylene copolymer having a functionality of greater than or equal to 4 and less than or equal to 6, a nominal molecular weight of greater than or equal to 180 Daltons and less than or equal to 1000 Daltons, and a hydroxyl value of greater than or equal to 200 milligrams of potassium hydroxide per gram and less than or equal to 400 milligrams of potassium hydroxide per gram. [8] The polyurethane material of claim 1, wherein the polyisocyanate comprises tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polyphenylene polymethylene polyisocyanate, hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), or a combination thereof, wherein the catalyst comprises a metal-containing catalyst and a tertiary amine catalyst. [9] The polyurethane material of claim 1, further comprising a crosslinker comprising a polyol having a molecular weight of greater than or equal to 50 grams per mole and less than or equal to 300 grams per mole. [10] Polyurethane material according to claim 1, wherein the polyurethane material is a polyurethane foam having a density of greater than or equal to 150 kilograms per cubic meter and less than or equal to 250 kilograms per cubic meter and a compressive force deformation of greater than or equal to 100 kilopascals and less than or equal to 800 kilopascals.

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