Unsaturated Polyester Resin Synthesis From Waste Polycarbonate
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Solution Overview
Problem
Existing methods for manufacturing unsaturated polyester resin from recycled materials are time-consuming and energy-intensive, and there is a need for a more efficient process that maintains mechanical strength while reducing carbon emissions.
Innovation Solution
A method involving alcoholysis, etherification, and condensation steps to produce unsaturated polyester resin from polycarbonate, using a catalyst and monomers, followed by dilution to achieve a shorter reaction time and lower temperatures, incorporating a curing process for the resin.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If recycled PET is reacted with propylene glycol, ethylene glycol, diethylene glycol, and a catalyst at 210°C for 6 hours, then unsaturated polyester resin can be obtained, but the overall reaction time takes more than 12 hours and consumes huge amounts of electrical power
Solution Approach 1:
The patent segments the manufacturing process into three distinct steps: (1) alcoholysis of polycarbonate with diol at 130-190°C for 1-4 hours to produce diol monomer, (2) condensation of diol monomer with dianhydride/diacid at 150-220°C for 1-3 hours to produce polyester oligomer, and (3) dilution with styrene/acrylic monomer. This segmentation allows optimization of each step's parameters, significantly reducing total reaction time while maintaining product quality
Solution Approach 2:
The patent changes key process parameters including temperature range (130-220°C), reaction time (1-4 hours per step), and catalyst selection (organic alkaline catalysts like DBU, TBD, or DMAP). These parameter optimizations enable the process to achieve complete reaction in 2-8 hours total, reducing both time and energy consumption while preserving mechanical strength
2Reliability
If recycled PET is reacted at 210°C for 6 hours with multiple glycols, then unsaturated polyester resin can be produced, but huge amounts of electrical power are consumed
Solution Approach 1:
The patent optimizes temperature parameters to 130-190°C for alcoholysis and 150-220°C for condensation, which are lower than conventional 210°C processing. Combined with efficient organic alkaline catalysts, this reduces heating energy requirements while maintaining reaction completeness and mechanical strength
Solution Approach 2:
The patent performs alcoholysis first to completely convert polycarbonate to diol monomer before proceeding to condensation. This preliminary action ensures that the subsequent condensation step proceeds efficiently with minimal energy input, as all polycarbonate is already transformed into reactive diol form
3Strength
If conventional methods are used to manufacture unsaturated polyester resin from recycled materials, then the process is time-consuming, but maintaining excellent mechanical strength is required
Solution Approach 1:
By dividing the synthesis into alcoholysis, condensation, and dilution steps, the patent enables parallel processing and optimization of each stage. This increases manufacturing efficiency through better resource allocation and process control while ensuring each step contributes to final mechanical strength
Solution Approach 2:
The patent uses organic alkaline catalysts (DBU, TBD, or DMAP) as intermediaries to accelerate both alcoholysis and condensation reactions. These catalysts lower activation energy barriers, enabling faster reaction rates that improve productivity without compromising the cross-linked network structure and mechanical strength
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 reduces manufacturing time and energy consumption, enables the use of waste polycarbonate, and produces resin with excellent mechanical strength, contributing to carbon reduction.
Implementation Method 1
In the alcoholysis step, a polycarbonate, a diol compound and an organic alkaline catalyst are mixed and heated to an alcoholysis temperature to obtain a first mixture
Implementation Method 2
In the etherification step, a carbonate compound is added to the first mixture and the carbonate compound and the first mixture are maintained at an etherification temperature to obtain a second mixture
Implementation Method 3
In the condensation step, the second mixture is cooled and a dianhydride monomer or a diacid monomer is added to the second mixture, and the second mixture and the dianhydride monomer or the diacid monomer are heated to a condensation temperature to obtain a third mixture
Implementation Method 4
This polymer can form a cross-linked network structure at the room temperature by being diluted with a monomer having free radicals and followed by the addition of a peroxide
Data Source
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AI summary
A method for manufacturing an unsaturated polyester resin includes alcoholysis step, etherification step, condensation step and dilution step as follows. In alcoholysis step, a polycarbonate, a diol compound and an organic alkaline catalyst are mixed and heated to an alcoholysis temperature to obtain a first mixture. In etherification step, a carbonate compound is added to the first mixture and the first mixture, and the carbonate compound are maintained at an etherification temperature to obtain a second mixture. In the condensation step, the second mixture is cooled and a dianhydride or diacid monomer is added, and the second mixture and the dianhydride or diacid monomer are heated to a condensation temperature to obtain a third mixture. In dilution step, the third mixture is cooled to a dilution temperature, and a styrene or acrylic monomer is added to dilute it to a predetermined solid content to obtain an unsaturated polyester resin.