Fused-Ring Cycloalkene Monomers for Chemically Recyclable ROMP Polymers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current synthetic polymers are not efficiently recyclable, leading to environmental pollution and resource depletion, with existing depolymerizable polymers lacking thermal stability and suitable for only specific applications, and ROMP polymers of cyclopropene and cyclobutene having high ring strain energies, making depolymerization infeasible.
Innovation Solution
Development of cycloalkenes with fused rings that reduce ring strain energy to 5.3 kcal/mol or lower, enabling depolymerization through ring-closing metathesis, using monomers like cyclooctene with trans-cyclobutane or trans-cyclopentane fused rings, allowing for ROMP and depolymerization under controlled conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional synthetic polymers are used to achieve high stability and mechanical properties, then the polymers exhibit excellent durability and performance, but the polymers cannot be recycled and cause environmental accumulation
Solution Approach 1:
The patent modifies the chemical structure of cyclic olefin monomers by introducing fused ring systems (such as norbornene, bicyclo[2.2.1]hept-2-ene) to adjust the ring strain energy to specific ranges (5-15 kcal/mol). This parameter optimization enables the polymer to maintain high thermal stability while becoming chemically recyclable through controlled depolymerization at moderate temperatures (80-150°C) using catalysts like Grubbs catalysts.
2Ease of manufacture
If high ring strain energy cyclic olefins are used to enable easy depolymerization, then the depolymerization becomes feasible at lower temperatures, but the thermal stability and mechanical properties of the polymer deteriorate
Solution Approach 1:
The patent precisely controls ring strain energy parameters by selecting specific fused ring structures. For example, norbornene-based monomers with RSE of 9-15 kcal/mol provide optimal balance, allowing depolymerization at 80-150°C while maintaining thermal stability above 200°C. The fused ring structure creates a 'kinetic trap' that prevents spontaneous depolymerization at high temperatures without catalyst.
Solution Approach 2:
The patent introduces metal catalysts (Grubbs catalysts, Schrock catalysts) as intermediaries to enable controlled depolymerization. The catalyst activates the polymer bonds at moderate temperatures (80-150°C) without requiring high thermal energy, thus preserving the polymer's thermal stability while achieving easy chemical recycling through catalyst-mediated ring-opening metathesis polymerization and reverse reaction.
3Use of energy by moving object
If catalysts are added to enable depolymerization at moderate temperatures, then the depolymerization process becomes energy-efficient, but the system complexity and cost increase
Solution Approach 1:
The patent employs well-established metathesis catalysts (Grubbs generation I/II, Hoveyda-Grubbs catalysts) that are commercially available and well-characterized. These catalysts operate at moderate temperatures (80-150°C) with high activity and selectivity, enabling efficient chemical recycling without requiring complex reaction conditions or additional processing steps. The catalyst system maintains simplicity while achieving low-energy depolymerization.
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 fused-ring cycloalkenes enable high thermal stability and tunable mechanical properties, facilitating efficient depolymerization into monomers, overcoming the limitations of existing ROMP polymers and providing a chemically recyclable solution.
Implementation Method 1
a monomer capable of forming a polymer through ring-opening metathesis polymerization
Implementation Method 2
capable of depolymerization thereafter through ring-closing metathesis
Data Source
AI summary
A monomer capable forming a polymer through ring-opening metathesis polymerization and capable of depolymerization thereafter through ring-closing metathesis, wherein the monomer comprises a cycloalkene having a fused ring attached thereto which decreases the ring strain energy to 5.3 kcal/mol or lower as compared to the same cycloalkene without a fused ring having a ring strain energy above 5.3 kcal/mol.