Amorphous Copolyester High Glass Transition Temperature
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Solution Overview
Problem
Commercially available amorphous polyesters have low glass transition temperatures, limiting their heat performance and range of applications.
Innovation Solution
An amorphous copolyester is developed using a specific combination of 1-phenylindane dicarboxylic acid and a terephthalyl component, along with 1,4-cyclohexanedimethanol, which achieves a glass transition temperature of at least 107°C, high intrinsic viscosity, and improved impact strength, utilizing recycled terephthalic acid-based polyesters with controlled impurities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If commercially available amorphous polyesters (PET, PETG, PCTG) are used, then impact properties are improved, but glass transition temperature is low which limits heat performance
Solution Approach 1:
The patent changes the chemical composition parameters of the polyester by incorporating specific monomer units (1-phenylindane dicarboxylic acid with 7-12 mole %, terephthalyl component with 40-60 mole %, and 1,4-cyclohexane dimethanol with 30-50 mole %) to simultaneously achieve high impact properties and high glass transition temperature (≥107°C), resolving the contradiction between impact strength and heat performance
Solution Approach 2:
The patent creates a composite polyester structure by combining multiple monomer types in specific proportions: aromatic dicarboxylic acid units for impact resistance, terephthalyl components for thermal stability, and cyclohexane dimethanol for flexibility. This composite approach allows simultaneous optimization of both impact properties and glass transition temperature
2Loss of substance
If recycled terephthalic acid-based polyesters are used with controlled impurities, then material costs are reduced and sustainability is improved, but manufacturing precision may be affected
Solution Approach 1:
The patent converts the potential harm of impurities in recycled materials into a benefit by establishing specific compositional ranges (1-phenylindane dicarboxylic acid: 7-12 mole %, terephthalyl component: 40-60 mole %, 1,4-cyclohexane dimethanol: 30-50 mole %) that ensure consistent product quality. This approach transforms variability in recycled materials into controlled, predictable composition through precise formulation
Solution Approach 2:
The patent implements feedback control by specifying precise compositional ranges and requiring controlled impurity levels in the recycled terephthalic acid-based polyester. This feedback mechanism ensures that variations in recycled material quality are compensated for by adjusting other formulation parameters to maintain consistent final product properties
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 copolyester exhibits enhanced thermal properties and impact strength, comparable to those produced from virgin monomers, while utilizing recycled materials, thus expanding its application range and reducing material costs.
Implementation Method 1
a copolyester comprising the reaction product of (a) a monomer of formula I... (b) a terephthalyl component... and (c) 1,4-cyclohexane dimethanol
Data Source
AI summary
An amorphous copolyester comprising the reaction product of (a) a monomer of formula Iwherein R1, R2, R3, and R5 are each independently a C1-3 alkyl group, a is 0-1, b is 0-4, c is 0-4 and d is 0-3, and each R4 is independently hydrogen or a C1-3 alkyl group; (b) a terephthalyl component selected from terephthalic acid, a di(C1-3 alkyl) terephthalate, and combinations thereof, derived from a terephthalyl-containing polyester; and (c) 1,4-cyclohexane dimethanol; wherein the monomer (a) units are present in an amount from 7 to less than 12 mole % of the copolyester based on the total moles of repeat units in the copolyester; and the copolyester has a glass transition temperature of at least 107° C., an intrinsic viscosity of at least 0.7 dl/g, and a molded sample has a Notched Izod value of at least 290 J/m determined in accordance with ASTM D256.