EP-4739722-A1 - COMPOSITES FORMED USING LEWIS-ACID POLYMERIZED POLYOLS AND METHODS OF PREPARING SAME

Abstract

Methods include forming a composite comprising, reacting: an isocyanate component; an isocyanate-reactive component that includes at least one Lewis acid catalyzed polyether polyol having a percent by weight (wt%) of 90 wt% or more polypropylene oxide, a primary hydroxy concentration of at least 30 wt%, a functionality of at least 2, an OH number in the range of 100 mg KOH/g to 800 mg KOH/g, an average acetal content of at least 0.05 wt%, and a water content in the range of 0.1 wt% to 2 wt% based on the weight of the isocyanate-reactive component; and wherein a reinforcing material is present in at least one of the isocyanate component, the isocyanate-reactive component, or a third component.

Inventors

• SUZUKI, MASAYUKI
• WANG, YUN
• SUN, GANG
• KEATON, An Nguyen
• BAGGIO, Enrico
• DIENA, PAOLO
• KEATON, RICHARD

Assignees

• Dow Global Technologies LLC

Dates

Publication Date

20260513

Application Date

20230706

Claims (10)

1. A method of forming a composite comprising, reacting: an isocyanate component; an isocyanate-reactive component that includes at least one Lewis acid catalyzed polyether polyol having a percent by weight (wt%) of 90 wt%or more polypropylene oxide, a primary hydroxy concentration of at least 30 wt%, a functionality of at least 2, an OH number in the range of 100 mg KOH/g to 800 mg KOH/g, an average acetal content of at least 0.05 wt%, and a water content in the range of 0.1 wt%to 2 wt%based on the weight of the isocyanate-reactive component; and wherein a reinforcing material is present in at least one of the isocyanate component, the isocyanate-reactive component, or a third component.
2. The method of claim 1, wherein the isocyanate-reactive component includes at least 50 wt%of the polyether polyol.
3. The method of claim 1, wherein the polyether polyol is a polypropylene oxide polyol.
4. The method of claim 1, wherein the composite has a density less than 0.85 g/mL.
5. The method of claim 1, wherein the polyether polyol has a weight average molecular weight from 200 Da to 1,000 Da, and a functionality of 2 to 4.
6. The method of claim 1, wherein the Lewis acid catalyst used to generate the polyether polyol has a general formula M (R 1 ) 1 (R 2 ) 1 (R 3 ) 1 (R 4 ) 0 or 1 , whereas M is boron, aluminum, indium, bismuth or erbium, R 1 , R 2 , R 3 , and R 4 are each independent, R 1 includes a first fluoro/chloro or fluoroalkyl-substituted phenyl group, R 2 includes a second fluoro/chloro or fluoroalkyl-substituted phenyl group, R 3 includes a third fluoro/chloro or fluoroalkyl-substituted phenyl group or a first functional group or functional polymer group, optional R 4 is a second functional group or functional polymer group.
7. The composition of claim 1, wherein the Lewis acid catalyst forms a dative bond with tetrohydrofuran.
8. The method of claim 1, wherein the isocyanate component is present at a percent by weight (wt%) ranging from 56 wt%to 86 wt%.
9. The method of claim 1, wherein the composite is prepared by long fiber injection (LFI) .
10. An article prepared by the method of claim 1.

Description

COMPOSITES FORMED USING LEWIS-ACID POLYMERIZED POLYOLS AND METHODS OF PREPARING SAME Field Embodiments relate to polyurethane compositions used in the fabrication of polyurethane composites and reinforced materials having improved mechanical properties. INTRODUCTION Polyurethane (PU) formulations may be manufactured into reinforced composites for structural parts using a number of methods including long fiber injection (LFI) , reinforced, reaction injection molding (RRIM) , and the like. For LFI methods, PU resins are sprayed or poured simultaneously with chopped fiber glass into an open mold. As the mold is covered by the LFI-PU material, the mold closes and compression takes place at elevated temperature triggering the cure of the polyurethane. The advantage of the LFI-PU fabrication process is the ability to employ reinforcement fibers of discontinuous in length, which can be concentrated at targeted structural locations. The final composite articles may then exhibit good surface quality and low thermal expansion. As with most fabrication technologies, the reduction of demolding time with maintained or improved product quality results in increased productivity. To reduce demolding time, higher loadings of catalysts or polyols containing higher concentrations of reactive primary hydroxyl groups (e.g., EO derivatives) can be used. However, the use of polyurethane catalysts can be prohibitively expensive, and can increase volatility and shorten the cure time of the formulation during processing. Polyols containing high concentrations of primary hydroxy groups may be obtained using EO as the alkoxylation reagent, which result in higher hygroscopicity, and can lead to accumulation of water in the formulation when exposed to the atmosphere. The increased polarity of EO-containing polyols can also lead to issues with compatibility with nonpolar formulation components and the generation of haze and turbidity. SUMMARY In an aspect, embodiments of the present disclosure include methods of forming a composite that include reacting an isocyanate component; an isocyanate-reactive component that includes at least one Lewis acid catalyzed polyether polyol having a percent by weight (wt%) of 90 wt%or more polypropylene oxide, a primary hydroxy concentration of at least 30 wt%, a functionality of at least 2, an OH number in the range of 100 mg KOH/g to 800 mg KOH/g, an average acetal content of at least 0.05 wt%, and a water content in the range of 0.1 wt%to 2 wt%based on the weight of the isocyanate-reactive component; and wherein a reinforcing material is  present in at least one of the isocyanate component, the isocyanate-reactive component, or a third component. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a graphical representation of compressive strength as a function of displacement for comparative and Lewis-acid polymerized polyols measured in accordance with ASTM D1621. DETAILED DESCRIPTION Embodiments relate to a two component polyurethane composition for use in composite manufacture in which the composition includes a specific type of Lewis acid catalyzed polyether polyol produced by polymerization in the presence of a perfluoroalkyl-substituted arylborane catalyst. The polyurethane composition includes an isocyanate component and an isocyanate reactive component that includes at least Lewis acid catalyzed polyether polyol. Lewis acid catalyzed polyether polyols disclosed herein may have a percent by weight (wt%) of 90 wt%or more polypropylene oxide, a primary hydroxy concentration of at least 30 wt%, a functionality of at least 2, an OH number in the range of 100 mg KOH/g to 800 mg KOH/g, and an average acetal content of at least 0.05 wt%. Methods also include the formation of a composite that include combining the components in the presence of a reinforcement material using a suitable process such as LFI. The use of a Lewis acid polymerization catalyst (e.g., perfluoroalkyl-substituted arylborane catalysts) to produce polyether polyols may improve polyol reactivity with the isocyanate component, particularly for polypropylene oxide based (or containing) polyether polyols, by increasing the percentage of primary hydroxyl groups. Increased concentrations of primary hydroxyl groups are associated with faster cure times and improved appearance of the final product. Comparative formulations that include concentrations of polyethylene oxide to increase the percentage of primary OH terminal functional groups, produces some decrease in demold time during manufacture. However, the presence of polyethylene oxide also leads to decreased compatibility with nonpolar polymer phases and layers such as PVC skin layers, production of an open cell structure prone to discoloration by oxidative gases, and high reactivity-related scorching. On the other hand, polypropylene oxide-based polyether polyols show good compatibility with nonpolar phases, but preparation of polyether polyols by standard KOH alkoxylation catalysi