Oligomeric PET Substrate End Group Optimization
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Solution Overview
Problem
Recycled PET (rPET) made from recycled bis-hydroxylethyleneterephthalate (rBHET) has lower reactivity and yield compared to virgin PET, making it less competitive in manufacturing processes.
Innovation Solution
Reacting rBHET or a higher molecular weight oligomer derived from rBHET with water to produce an oligomeric PET substrate with specific end group ratios and conditions, enhancing its reactivity for use in rPET manufacturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If rBHET is used to manufacture rPET, then recycled PET production is enabled with lower carbon footprint, but reactivity and yield are lower compared to virgin PET
Solution Approach 1:
The patent modifies the end group composition of the oligomeric PET substrate by controlling the ratio of hydroxyl to carboxyl end groups (targeting a ratio of 1.66 to 6.66, preferably 2.22 to 4.0). This parameter change in the chemical structure enhances the reactivity of rBHET-derived oligomers during polycondensation, thereby improving both reactivity and yield of rPET production while maintaining the environmental benefits of recycling
Solution Approach 2:
The patent creates an optimized oligomeric PET substrate that combines rBHET with specific end group configurations (both hydroxyl and carboxyl groups in controlled ratios). This composite approach at the molecular level allows the recycled material to achieve reactivity levels comparable to virgin PET by incorporating functional end groups that facilitate efficient polycondensation reactions
2Ease of manufacture
If conventional rBHET is used in PET manufacturing, then recycled PET can be produced, but the process is less economically competitive with virgin PET production
Solution Approach 1:
By optimizing the hydroxyl to carboxyl end group ratio in the oligomeric PET substrate to specific ranges (1.66 to 6.66, preferably 2.22 to 4.0), the patent improves reaction efficiency and yield. This parameter optimization reduces processing costs and increases productivity, making rPET manufacturing economically competitive with virgin PET production while maintaining recycled content benefits
3Reliability
If the oligomeric PET substrate has optimized end group ratios, then reactivity increases, but process complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-adjusting the end group composition (hydroxyl to carboxyl ratio of 1.66 to 6.66) of the oligomeric PET substrate before the polycondensation process. This pre-optimization of molecular structure ensures high reactivity during manufacturing without requiring complex process controls or additional processing steps, thereby maintaining manufacturing simplicity while achieving improved reactivity
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
Increases the reactivity and yield of rPET, making it economically competitive with virgin PET production processes by optimizing the oligomeric PET substrate's structure and reaction conditions.
Implementation Method 1
Reacting rBHET or a higher molecular weight oligomer derived from rBHET with water to produce an oligomeric PET substrate
Data Source
AI summary
A method for producing an oligomeric polyethylene terephthalate (PET) substrate for use in a recycled PET (rPET) manufacturing process comprises adding recycled bis-hydroxylethyleneterephthalate (rBHET) or a higher molecular weight oligomer derived from rBHET and water to a reaction zone and reacting the rBHET and water in the reaction zone to produce an oligomeric PET substrate represented by the Formula (I): wherein R1 is a carboxyl end group or a hydroxyl end group, R2 is a carboxyl end group or a hydroxyl end group, and n is a degree of polymerisation (Dp).