Grantee Research Project Results
Final Report: Feasibility of rPET Lignin-Content Polylols for Significant Reduction of Halogenated Flame Retardant in Construction Spray Foam
EPA Contract Number: 68HE0D18C0015Title: Feasibility of rPET Lignin-Content Polylols for Significant Reduction of Halogenated Flame Retardant in Construction Spray Foam
Investigators: Tabor, Rick
Small Business: Resinate Materials Group
EPA Contact: Richards, April
Phase: I
Project Period: October 1, 2018 through March 31, 2019
Project Amount: $91,661
RFA: Small Business Innovation Research (SBIR) - Phase I (2018) RFA Text | Recipients Lists
Research Category: Small Business Innovation Research (SBIR) , SBIR – Sustainable Materials Management
Description:
The focus of this work was the design and development of lignin-containing polyols for commercial use in the foam industry as a means of reducing or removing halogenated flame-retardant agents from foam formulations. Multiple synthetic processes were developed to produce Primary Lignin Polyols and Intermediate Lignin Polyols which also possess rPET content and complimentary recycled/renewable components, as well as Lignin Concentrate Polyols which afford incorporation of higher levels of lignin content. These polyols were synthesized, analyzed, and evaluated for physical properties and fire performance in PIR laminate foam formulations among other applications. Throughout this project work process improvements in health & safety, analytical techniques, and raw material sourcing were performed to evaluate the robustness and application of this technology on a commercial scale. Synthesis was scaled from laboratory scale to pilot batches with a scheduled manufacturing scale trial pending. A number of resulting polyols have been sampled to customers for evaluation and commercial feedback.
Summary/Accomplishments (Outputs/Outcomes):
Analytical efforts have determined that the hydroxyl functionality of our commercially available lignin is in the range of 6.8-8.3. Primary Lignin Polyols were prepared and evaluated in PIR rigid foam testing. Initial results have yielded improved compressive strength and reduced mass loss, flame height, flame out time, and char area in CAL TB 117 burn testing. Two were successfully scaled up in our 30-liter pilot scale facility, and we identified a promising reactor clean out protocol for use in eliminating lignin staining and contamination between batches and distillate treatment that mitigates odors for waste-water treatment facilities. Four Lignin Intermediate Polyols suitable for use preparing a fully formulated primary lignin polyol were prepared using low cost / low quality PET. No filtration issues were encountered, and lignin was simply blended into one of these polyols with modest heating and stirring, providing a reduced cost route. Lignin Concentrate Polyols (30% lignin content) were evaluated and determined to be relatively ineffective in PIR foam evaluations using a phthalate base polyol. These concentrates did not contain rPET, which we believe to be required for synergistic interaction with the lignin to rapidly form char during flame exposure. One of these lignin concentrates (LNP1010-6.9) yielded excellent results in a polyether elastomer when combined with Fyrol 6 (via UL-94). The six lowest smoke density foams (via ASTM E662) were based on lignin-containing polyols. Additionally, testing indicated that a non-halogenated rPET / lignin based PIR foam provided a 47.5% reduction in smoke versus a halogenated (TCPP) phthalate-based PIR foam. Toxic Gas Emission testing (BSS 7239) revealed that PIR rigid foams containing lignin, in combination with the non-halogenated FR agent triethyl phosphate, generally yielded lower toxic combustion gas emissions versus PIR rigid foams containing halogenated FR agents.
Conclusions:
It is clear that lignin provides a dramatic, non-halogenated option for improving burn performance and reducing smoke generation in PIR rigid foams versus halogen-content rigid foams, when combined with recycled PET content in a primary polyol. These polyols are readily produced on a 5-gallon pilot plant scale and it is believed that they can be readily produced at full scale manufacturing scale, since this grant has enabled the elimination of numerous production obstacles. Additionally a lignin concentrate polyol has been developed that shows promise as an FR additive for use in polyether thermoset applications.
Commercialization:
Resinate has currently paid 50% of an invoice ($4000) to InChem, a toll manufacturer in South Carolina, in order to conduct 30 gallon manufacturing of our Primary Lignin Polyol LNP1015-1.6. InChem originally promised this production run to us for February. However, equipment installations required in order to run lignin have not been completed as of the time of this writing. Samples of lignin polyols have been sent for evaluation to at least 6 companies, and thanks to Foresights Market Research, another 14 potential customers have been identified.
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.