Coupled Recycled Polypropylene for Blow Molding Melt Strength
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Post-consumer recycled (PCR) propylene-based polymers exhibit unsuitable physical properties, such as melt flow rate and melt strength, limiting their application in blow molding and other molding processes due to contamination during sorting.
Innovation Solution
A process involving the addition of 4,4′-oxydibenzenesulfonyl azide (DPO-BSA) to PCR-PP, followed by melt blending, results in a DPO-BSA coupled PCR-PP with a melt flow rate of 5 g/10 min or less, enhancing its melt strength and suitability for molding applications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If post-consumer recycled polypropylene is used in blow molding applications, then environmental sustainability is improved, but the material exhibits unsuitable physical properties (melt flow rate and melt strength) due to contamination
Solution Approach 1:
The patent changes the chemical parameter of the PCR-PP by coupling DPO-BSA to the polymer chains. This chemical modification alters the melt flow rate from ≥7.0 g/10 min to ≤5 g/10 min, thereby improving melt strength and making the material suitable for blow molding applications while maintaining its recycled status
Solution Approach 2:
The patent creates a composite system by combining PCR-PP with DPO-BSA coupling agent. This composite approach allows the recycled polymer to gain enhanced properties (melt strength and ductile behavior) through the additive, resolving the contradiction between using recycled material and achieving suitable physical properties
2Object-affected harmful factors
If sorting technology is used to separate PCR polymers, then contamination is reduced, but the sorting process is not perfect and contamination remains
Solution Approach 1:
The patent accepts the unavoidable contamination from sorting as a given condition and converts this limitation into an opportunity by developing a chemical coupling process that works effectively with contaminated PCR-PP. The DPO-BSA coupling method is designed to improve melt strength regardless of the presence of contaminants, thereby turning the sorting limitation into a non-critical factor
3Stability of the object's composition
If virgin polypropylene is used instead of PCR-PP, then suitable physical properties are achieved, but environmental sustainability is compromised
Solution Approach 1:
The patent modifies the physical parameters of PCR-PP through chemical coupling with DPO-BSA, achieving melt flow rate ≤5 g/10 min and improved melt strength. This allows recycled material to replace virgin polypropylene while maintaining the required physical properties for blow molding applications
Solution Approach 2:
The patent enables PCR-PP to serve itself by improving its own properties through chemical modification rather than requiring replacement with virgin material. The coupling process enhances the recycled polymer's performance, allowing it to meet application requirements without compromising environmental sustainability
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 DPO-BSA coupled PCR-PP achieves improved melt strength and ductile behavior, making it suitable for blow molded articles and other molded products.
Implementation Method 1
adding a 4,4'-oxydibenzenesulfonyl azide (DPO-BSA) to the PCR-PP; (iii) melt blending the PCR-PP with the DPO-BSA; and (iv) forming a DPO-BSA coupled PCR-PP
Data Source
AI summary
The present disclosure provides a process. The process includes (i) providing a post-consumer recycled polypropylene (PCR-PP) having a melt flow rate (MFR I2) equal to, or greater than, 7.0 g/10 min; (ii) adding a 4,4′-oxydibenzenesulfonyl azide (DPO-BSA) to the PCR-PP; (iii) melt blending the PCR-PP with the DPO-BSA; and (iv) forming a DPO-BSA coupled PCR-PP having a melt flow rate (MFR I2) equal to, or less than, 5 g/10 min.