Ketal-Based Polymer Closed-Loop Recycling
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Solution Overview
Problem
Petroleum-based plastics are durable and versatile but pose significant environmental challenges due to their persistence in the environment, with limited recycling rates and potential for bioaccumulation, as they are difficult to recycle and often end up in landfills or oceans, leading to environmental contamination.
Innovation Solution
A method for producing and recycling polymers using a mixture of a monomer compound, a carbonyl compound, and a base, which forms a polymer that can be degraded back into reusable monomers, utilizing glycerol and hydroxyacetone to create a ketal-based polymer that can be depolymerized under specific conditions, allowing for a 'closed-loop' recycling process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If petroleum-based plastics are used for their durability and versatility, then the plastic serves its functional purpose effectively, but the plastic accumulates in the environment and causes pollution when discarded
Solution Approach 1:
The patent changes the chemical parameters of the polymer by incorporating labile bonds (acetal, ketal, orthoester groups) into the polymer backbone, transforming it from a permanently stable structure to one that is stable under use conditions but degradable under specific environmental conditions (pH, temperature, enzymes), thus resolving the contradiction between durability and environmental persistence
Solution Approach 2:
The patent creates a dynamic polymer system that can transition between stable and degradable states. The polymer maintains structural integrity during its service life but can be triggered to decompose into monomers under specific conditions (acidic environment, enzymatic action, heat), enabling it to adapt its stability based on environmental conditions rather than remaining statically durable
2Ease of repair
If traditional plastic recycling methods are used, then some plastic is recovered, but the recycling rate remains low and most plastic waste ends up in landfills or oceans
Solution Approach 1:
The patent designs the polymer as a segmented or modular structure composed of repeating monomer units connected by labile bonds. This segmentation allows the polymer to be easily broken down into its constituent monomers through chemical recycling processes, transforming the indigestible long-chain polymer into recyclable building blocks that can be repolymerized to create new plastic products
Solution Approach 2:
The patent enables a circular economy approach where the polymer is designed to be discarded in a controlled manner through depolymerization. The labile bonds allow the polymer to break down into monomers that can be recovered, purified, and reused to manufacture new polymers, creating a closed-loop system that eliminates permanent waste accumulation
3Adaptability or versatility
If petroleum-based plastics are produced, then versatile materials are created for various applications, but additives in plastics leech into the environment and bioaccumulate in humans
Solution Approach 1:
The patent changes the chemical composition parameters by replacing petroleum-based monomers with bio-based alternatives (sugars, amino acids, fatty acids) and using labile bond linkages. This transformation maintains the polymer's functional versatility while ensuring that degradation products are non-toxic, naturally occurring compounds that do not bioaccumulate, thus resolving the contradiction between functionality and environmental safety
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 method enables the production of polymers with comparable thermal properties to existing polycarbonates while offering the potential for complete degradation back into environmentally benign small molecules, facilitating efficient recycling and reducing environmental impact.
Implementation Method 1
forming a mixture comprising a monomer compound according to Formula I, a carbonyl compound according to Formula III, and a base
Implementation Method 2
heating the mixture to a first temperature of from 80° C. to 150° C. for a first time period, such as a first time period of from greater than zero to 4 hours, then heating the mixture to a second temperature of from greater than 150° C. to 300° C. for a second time period
Implementation Method 3
heating the mixture to a first temperature of from 80° C. to 150° C. for a first time period, such as a first time period of from greater than zero to 4 hours, then heating the mixture to a second temperature of from greater than 150° C. to 300° C. for a second time period
Implementation Method 4
The method may further comprise introducing a vacuum while heating the mixture to the second temperature. The vacuum may reach a pressure of less than 500 mtorr, such as a pressure of from greater than zero to 250 mtorr
Implementation Method 5
forming a mixture comprising a protic organic solvent and a polymer according to the present disclosure, and heating the mixture to a temperature of from 30° C. to 150° C. or more
Implementation Method 6
heating the mixture to a temperature of from 30° C. to 150° C. or more, such as from 40° C. to 100° C. The mixture may be heated for a time period of from greater than zero to 7 days, such as from 12 hours to 3 days
Data Source
AI summary
Disclosed herein are embodiments of a method for making recyclable polymers and a method for decomposing the polymers back to the monomers which can then be reused. The polymer are stable to aqueous and/or acid conditions and may have a formula IIThe method to decompose the polymer back to the monomers may comprise heating the polymer in a protic organic solvent.