Recycled ABS Resin Depolymerization via Metal Carboxylic Acid Salt
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for recycling ABS resin face challenges in preventing deterioration of physical properties, particularly surface characteristics, due to the presence of impurities like polyurethane and other foreign matter.
Innovation Solution
A method involving the preparation of an extrusion feed containing an ABS base resin, polyurethane, a metal carboxylic acid salt, and a polyhydric alcohol, which is then supplied to an extruder to perform a depolymerization reaction of the polyurethane, thereby minimizing deformation and maintaining equivalent physical properties to new ABS resin.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If waste ABS resin including polyurethane and other impurities is melted at high temperature to be pelletized, then the recycled resin can be manufactured, but deformation and deterioration of physical properties occur due to impurities
Solution Approach 1:
The patent applies preliminary action by adding a depolymerization catalyst and performing depolymerization treatment before the main melting and pelletization process. The catalyst is mixed with the waste ABS resin and polyurethane impurities, and depolymerization is carried out at a specific temperature range (150-250°C) before the high-temperature melting step, thereby breaking down the polyurethane structure in advance to prevent surface deterioration during subsequent processing
Solution Approach 2:
The patent utilizes parameter changes by controlling the depolymerization temperature (150-250°C) which is lower than the melting temperature, and by adjusting the catalyst concentration (0.1-5 wt%) to achieve selective breakdown of polyurethane while preserving the ABS resin structure. This parameter control enables differentiation between the polyurethane impurities and the valuable ABS resin
2Ease of manufacture
If mechanical recycling is used to process waste ABS resin, then the recycling process is simple, but it is not easy to separate waste plastic as a single type and foreign matter remains at 1-5%
Solution Approach 1:
The patent applies the extraction principle by selectively removing polyurethane impurities from the waste ABS resin through depolymerization. The catalyst specifically targets and breaks down the polyurethane molecular structure, converting it into removable byproducts that can be separated from the ABS resin during the melting and filtration process, thereby reducing foreign matter content without requiring complex separation equipment
Solution Approach 2:
The depolymerization catalyst acts as an intermediary substance that facilitates the selective decomposition of polyurethane. The catalyst (such as organometallic compounds or enzymes) mediates the chemical reaction between the polyurethane impurities and the processing conditions, enabling selective breakdown while leaving the ABS resin intact
3Manufacturing precision
If chemical recycling is used to extract specific polymer from waste plastics, then pure monomolecules can be obtained, but the reaction and process become difficult for ABS resin which is a terpolymer
Solution Approach 1:
The patent applies segmentation by targeting only the polyurethane component within the complex waste material mixture, rather than attempting to decompose the entire ABS resin structure. The catalyst selectively acts on the polyurethane segments, breaking them down into removable fragments while leaving the ABS terpolymer structure intact, thereby simplifying the overall process
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 effectively stabilizes the depolymerization reaction of polyurethane at high temperatures and pressures, reducing the influence of impurities and resulting in a recycled ABS resin with minimal deformation and equivalent physical properties to new ABS resin.
Implementation Method 1
supplying the extrusion feed to an extruder to perform a depolymerization reaction of the polyurethane
Implementation Method 2
supplying the extrusion feed to an extruder to perform a depolymerization reaction of the polyurethane
Data Source
AI summary
Provided is a method for preparing a recycled ABS resin, and the method for preparing a recycled ABS resin includes: preparing an extrusion feed including an acrylonitrile butadiene styrene (ABS) base resin including polyurethane, a metal carboxylic acid salt, and a polyhydric alcohol; and supplying the extrusion feed to an extruder to perform a depolymerization reaction of the polyurethane and extruding the extrusion feed.