Tannin-Based Foams for Insulation Without Formaldehyde

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Solution Overview

Problem

Current insulation materials for buildings face challenges such as high thermal conductivity, flammability, and environmental concerns due to the use of materials like glass and mineral fibers, polymeric foams, and phenolic foams, which lack low thermal conductivity, fire resistance, and sustainability.

Innovation Solution

Development of tannin-based foams with a continuous polymeric phase derived from tannins and specific monomers like furfural, glyoxal, and furfuryl alcohol, combined with blowing agents and acid catalysts, to create closed-cell structures with low thermal conductivity and improved fire resistance, using renewable resources and minimizing ozone depletion and global warming potential.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If phenolic foams are used for insulation, then flame resistance is improved, but environmental harm increases due to formaldehyde content and petroleum-based feedstock

Engineering Contradiction:

Improvefire resistanceVSAvoidformaldehyde content and environmental impact

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention changes the chemical composition parameters by replacing formaldehyde with furfuryl alcohol and petroleum-based phenol with tannin extract, thereby eliminating carcinogenic formaldehyde while maintaining the flame-resistant properties of phenolic foams through the tannin-phenol reaction mechanism

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention uses readily available tannin extract from bark as a renewable, cost-effective alternative to expensive petroleum-based phenol, making the foam production more sustainable and environmentally friendly without sacrificing performance

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Loss of energy

If closed-cell foam structure is created with blowing agents, then thermal conductivity is reduced, but environmental harm increases due to ozone depletion potential of traditional blowing agents

Engineering Contradiction:

Improvethermal conductivityVSAvoidozone depletion potential

Core Design Contradiction:

Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The invention changes the blowing agent from traditional high-ODP substances to environmentally friendly alternatives with low or zero ozone depletion potential, thereby maintaining the closed-cell structure and low thermal conductivity while eliminating environmental harm

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention converts the previously harmful blowing agents into beneficial environmentally friendly alternatives, using substances with low ODP and GWP that still effectively create the closed-cell structure needed for thermal insulation, thereby turning a source of environmental harm into a sustainable solution

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Ease of manufacture

If polymeric foams are used for insulation, then ease of manufacture is improved, but fire resistance deteriorates due to high flammability

Engineering Contradiction:

Improvefoam productionVSAvoidfire resistance

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The invention creates a composite material system combining tannin extract with furfuryl alcohol and phenolic compounds, integrating the ease of foam formation from polymeric structures with the fire-resistant properties of tannin-based phenolic resins, thereby achieving both manufacturability and fire safety

Inventive Principle:

Principle #40Composite materials

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The tannin-based foams achieve low thermal conductivity (0.015-0.05 W/m·K), high fire resistance, and sustainability, making them suitable for building insulation while reducing environmental impact.

Implementation Method 1

mixing 5-30% by weight of an acid catalyst with the pre-foam mixture to form a foam composition

Methodology Applied

Scientific EffectCatalysis: Catalysis

Implementation Method 2

mixing 1-30% by weight of one or more blowing agents with the agglomerate-free solution to form a pre-foam mixture

Methodology Applied

Scientific EffectGas expansion: Phase Change

Data Source

PatentUS9790342B2Closed-cell tannin-based foams without formaldehyde

Publication Date: 2017.10.17 DUPONT SAFETY & CONSTRUCTION INC

AI summary

Disclosed are foam compositions and processes to form closed-cell tannin-based foams. The foams comprises a continuous polymeric phase defining a plurality of cells, wherein the continuous polymeric phase comprises a tannin-based resin derived from a tannin and a monomer, wherein the monomer comprises furfural, glyoxal, acetaldehyde, 5-hydroxymethylfurfural, acrolein, levulinate esters, sugars, 2,5-furandicarboxylic acid, 2,5-furandicarboxylic aldehyde, urea, difurfural (DFF), furfuryl alcohol, glycerol, sorbitol, lignin, or mixtures thereof, and wherein the plurality of cells comprises a plurality of open-cells and a plurality of closed-cells with an open-cell content measured according to ASTM D6226-5, of less than 50%. The foam composition also comprises a discontinuous phase disposed in at least a portion of the plurality of closed-cells, the discontinuous phase comprising one or more blowing agents.