{"id":46700,"date":"2024-04-03T14:05:47","date_gmt":"2024-04-03T06:05:47","guid":{"rendered":"http:\/\/www.newtopchem.com\/?p=46700"},"modified":"2024-04-03T14:05:47","modified_gmt":"2024-04-03T06:05:47","slug":"calculation-of-catalysts-in-polyurethane-soft-foam-formulations","status":"publish","type":"post","link":"http:\/\/www.newtopchem.com\/archives\/46700","title":{"rendered":"Calculation of catalysts in polyurethane soft foam formulations","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"
The kinetics of the reaction between hydroxyl compounds and isocyanates
\n-D (- NCO)\/dt=K0 x (- NCO) x (- OH)
\nK1 is the forward reaction rate of the formation of complexes between isocyanates and hydroxyl compounds
\nK2 is the negative reaction rate of the formation of complexes between isocyanates and hydroxyl compounds
\nK3 is the forward reaction rate at which complexes react with hydroxyl compounds to form aminoformates and hydroxyl compounds.
\nK0=[K1 x K3 x (- OH)]\/[K2+K3 x
\nArrhenius equation
\nK=Ae ^ [- (Ea\/RT)]
\nA: Exponential factor.
\nE=2.718
\nEa: KJ\/mol
\nR=8.31 (J\/mol. K)
\nCalculation of reaction heat for the formation of functional groups such as urea, polyurethane, biuret, and urea formate:
\nBond dissociation energy (KJ\/mol)
\nC-N 205.1~251.2
\nC-C 230.2~293.0
\nC-O 293.0-314.0
\nN-H 351.6~406.0
\nC-H 364.9~393.5
\nO-H 422.8~460.5
\nC=C 418.6~523.3
\nC=O 594.1~694.9
\nReactive equation
\nRNCO+rOH \u2192 RNHCOOr
\nRNCO+HOH \u2192 RNHCOOH+RNCO \u2192 RNHCONHR+OCO \u2191
\nRNHCOOr+RNCO \u2192 RNCONHRCOOr
\nRNHCONHr+RNCO \u2192 RNCONHRCONHr
\nThe volume ratio of gas to the total volume of the polymerization system (Vg\/Vo) in the polymerization system affects the temperature control ability: gas monomers affect the concentration (mol\/L), which affects the polymerization heat [Q (KJ\/L)=Rp (mol\/L) * (- H)]. The heat of polymerization is transferred to the gas dispersion medium, causing the gas to absorb heat and expand (PV=NR\/T). After a sudden increase in temperature in the polymerization system, the gas releases and carries away a large amount of heat (approximately in a straight line with Vg\/Vo)
\nWhen preparing polyurethane in one step, the activation energy of amino acids is about 60 (mol. K), and the activation energy of urea reaction is 17 (mol. K)
\nThe foam system is easier to implement than the solution suspension system. Dispersive polymerization exhibits the Norrish Tromasof effect at the beginning of the reaction, slowing down the rate of change of chain growth parameters over time and improving the monodispersity of the product.
\nDispersion polymerization is a method of separating the polymerization system into numerous fine foam by gas, so that the polymerization components can be converted into the surface liquid film of foam and the “polyhedral boundary liquid cell” connecting multiple liquid films can form a special dispersion phase for polymerization.
\nThe foam system uses gas as the dispersion medium, and the gas expands and cools suddenly when it is heated, and the negative pressure generated when the gas escapes will further polymerize the residual single concentration of the system, and accelerate and carry the evaporation of water molecules and the removal of small molecules.
\nThe dispersion effect of gas on the polymerization system is not equivalent to true dilution of monomers.
\nGeneral formula for half-life of non first-order reactions
\nT=[2 ^ (n-1) -1]\/[a x k x (n-1) x A ^ (n-1)]
\nSecond order reaction rate constant
\nA+B \u2192 Q+S
\nKt=[1\/(CA0-CB0)] x ln [(CB0 x CA)\/(CA0 x CB)]
\nCA0 x Kt=[1\/(1-M)] x ln {[M (1-xA)]\/(M-xA)}, where M=CB0\/CA0<\/h6>\n
Attachment:
\nExample of calculating the density of polyurethane soft foam
\nUniversal polyether ternary alcohol Ppg: 50 pop: 50 tdi-80:42.8 hoh: 3.17 L-580:1 a33:0.34 sn: 0.17
\nCalculated: 4.34 2.17 6.51 38.2 112% 17% 5.2 1.74 122 Recalculated, 28kg\/cubic meter
\nExample of Calculation for Polyurethane Soft Foam Catalysts
\nUniversal polyether ternary alcohol ppg: 90 pop: 10 tdi-80:: 35.5 hoh: 2.2 L-580:0.84 Black slurry: 6
\nCalculated: A33:0.18 T-9:0.25
\nA33:0.14 T-9:0.24
\nA33:0.13 T-9:0.35
\nA33:0.12 T-9:0.30
\nTolerance and turning points
\nCalculation of vertical foam flow rate and lifting speed:
\nFormula (for example only) PPG: 100, TDI: 80, HOH: 6, SI: 1.5, A33: * * *, SN: * * *, MC: 14.8
\nThe diameter of the vertical bubble circular mold is 1.25.
\nPolyether flow rate is 12 kilograms per minute.
\nWhat is the speed of improvement in meters per minute
\nCalculate the formula density of 12 kilograms per cubic meter. The total weight of the formula is 173.5 kilograms. The formula volume is 14.46 cubic meters. Circular mold cross-sectional area: 1.23 square meters.
\nSet a loss rate of 5%.
\nBoosting speed: [14.46 x 12% x (1-5%)]\/1.23=1.34 meters per minute.<\/h6>\n
\nRelated reading recommendations:<\/h6>\n

Dabco amine catalyst\/Low density sponge catalyst<\/a><\/h3>\n

High efficiency amine catalyst\/Dabco amine catalyst<\/a><\/h3>\n

Non-emissive polyurethane catalyst\/Dabco NE1060 catalyst<\/a><\/h3>\n

Dabco NE1060\/Non-emissive polyurethane catalyst<\/a><\/h3>\n

NT CAT A-33<\/a><\/h3>\n

NT CAT A-1<\/a><\/h3>\n

NT CAT 33L<\/a><\/h3>\n

NC CAT T<\/a><\/h3>\n

NT CAT 33LV<\/a><\/h3>\n

3-morpholinopropylamine<\/a><\/h3>\n

4-Acryloylmorpholine<\/a><\/h3>\n

N-Acetylmorpholine<\/a><\/h3>\n

N-Ethylmorpholine<\/a><\/h3>\n","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"

The kinetics of the reaction between hydroxyl compounds…<\/p>\n","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[6],"tags":[],"gt_translate_keys":[{"key":"link","format":"url"}],"_links":{"self":[{"href":"http:\/\/www.newtopchem.com\/wp-json\/wp\/v2\/posts\/46700"}],"collection":[{"href":"http:\/\/www.newtopchem.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.newtopchem.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.newtopchem.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.newtopchem.com\/wp-json\/wp\/v2\/comments?post=46700"}],"version-history":[{"count":1,"href":"http:\/\/www.newtopchem.com\/wp-json\/wp\/v2\/posts\/46700\/revisions"}],"predecessor-version":[{"id":46702,"href":"http:\/\/www.newtopchem.com\/wp-json\/wp\/v2\/posts\/46700\/revisions\/46702"}],"wp:attachment":[{"href":"http:\/\/www.newtopchem.com\/wp-json\/wp\/v2\/media?parent=46700"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.newtopchem.com\/wp-json\/wp\/v2\/categories?post=46700"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.newtopchem.com\/wp-json\/wp\/v2\/tags?post=46700"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}