GREEN ALTERNATIVE POLYURETHANE ADHESIVE
Disclosed is a two-component, liquid curable polyurethane adhesive system comprising an isocyanate reactive part A and an isocyanate functional part B. Either or both parts include substantial amounts of sustainable materials. The inventive mixed adhesive compositions are able to effectively bond to a separation membrane of a filtration apparatus. The invention is also directed to a method of bonding filter assembly components using this two-component curable polyurethane adhesive composition and a filter assembly bonded together using this adhesive composition.
1 . A two-part curable polyurethane adhesive composition, including:
part A comprising an isocyanate reactive component; a sustainable reactive rheology modifier, glycerol and optionally additives; and
part B comprising a polyisocyanate and optionally additives;
wherein the polyurethane adhesive composition comprises at least 60 wt. % sustainable materials by weight of the composition.
2 . The two-part curable polyurethane adhesive composition of claim 1 , wherein part B comprises an isocyanate functional polyurethane prepolymer that is the reaction product of MDI or modified MDI and an isocyanate reactive component.
3 . The two-part curable polyurethane adhesive composition of claim 1 , wherein the part A isocyanate reactive component is 95-100% sustainable.
4 . The two-part curable polyurethane adhesive composition of claim 1 , wherein the part A isocyanate reactive component comprises a sustainable plant oil having 2 to 4 hydroxyl groups.
5 . The two-part curable polyurethane adhesive composition of claim 1 , wherein the reactive rheology modifier comprises natural beeswax.
6 . A separation apparatus comprising:
a membrane capable of separating a first constituent from a feed fluid mixture comprising the first constituent and a second constituent; and
a mixed, two component polyurethane adhesive disposed in one or more discrete areas on the membrane, wherein the two-component polyurethane adhesive comprises:
part A comprising an isocyanate reactive component; a sustainable reactive rheology modifier, glycerol and optionally additives; and
part B comprising a polyisocyanate and optionally additives;
wherein the polyurethane adhesive composition comprises at least 60 wt. % sustainable materials by weight of the composition and the mixed, two component polyurethane adhesive has a percent penetration into the membrane layer prior to curing.
7 . The separation apparatus according to claim 6 , wherein the percent penetration of the membrane layer by the polyurethane adhesive is at least 5%.
8 . The separation apparatus according to claim 6 , wherein the percent penetration of the membrane layer by the polyurethane adhesive is at least 50%.
9 . The separation apparatus according to claim 6 , wherein the percent penetration of the membrane layer by the polyurethane adhesive is at least 80%.
10 . The separation apparatus according to claim 6 , wherein the separation apparatus further comprises a feed carrier material.
11 . The separation apparatus according to claim 6 , wherein the separation apparatus further comprises a porous permeate carrier layer which is bonded with the two-component polyurethane adhesive.
12 . The separation apparatus according to claim 6 , wherein the part A has a viscosity of less than 100,000 cPs at 25° C.
13 . The separation apparatus according to claim 6 , wherein the viscosity of part A at 25° C. is less than 30,000 cPs, measured on a Brookfield viscometer at 20 RPM and spindle 6 .
14 . The separation apparatus according to claim 6 , wherein the component A and the component B are present in a stoichiometric ratio of 0.95:1 to 1.40:1 based on the number of moles of isocyanate groups in part B and the number of moles of isocyanate-reactive groups in part A.
15 . The separation apparatus according to claim 6 , wherein part A comprises 50 wt. % to 95 wt. % castor oil as the isocyanate reactive component and 0.5 wt. % to 20 wt. % beeswax as the sustainable reactive rheology modifier.
16 . The separation apparatus according to claim 6 , wherein the polyisocyanate comprises methylene diphenyl diisocyanate.
17 . (canceled)
18 . (canceled)
19 . The separation apparatus according to claim 6 , wherein the separation apparatus is spiral wound membrane filter.
20 . The separation apparatus according to claim 6 , wherein the membrane comprises at least two layers.
21 . The separation apparatus according to claim 6 , wherein the membrane comprises a polyamide layer and a polysulfone layer.