Thermoplastic Polyurethane Fuel Barrier Composition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing polyurethane polymers lack sufficient resistance to aliphatic hydrocarbon fuels and hydrolytic stability, making them unsuitable for flexible fuel tanks that require prolonged flexibility, resiliency, and structural integrity in extreme conditions.
Innovation Solution
A high molecular weight thermoplastic polyurethane composition synthesized from poly(diethylene adipate) glycol reacted with a non-hindered diisocyanate and an aliphatic chain extender, specifically using poly(diethylene adipate) glycol, 1,4-butanediol, and methylene diphenyl isocyanate, with benzyl butyl phthalate as a plasticizer, to create a fuel-resistant barrier for flexible fuel containers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional thermoplastic polyurethanes are used to provide flexibility, then flexibility is improved, but fuel resistance and hydrolytic stability deteriorate
Solution Approach 1:
The patent changes the chemical composition parameters of the polyurethane by using specific polyols (polyester polyol with 60-80% adipate content, polyether polyol with 60-80% ether content) and controlling the ratio of polyester to polyether polyol (40:60 to 60:40). This parameter optimization simultaneously achieves flexibility and fuel resistance, resolving the contradiction between ease of operation and reliability.
Solution Approach 2:
The patent creates a composite polyurethane system combining polyester polyol and polyether polyol in specific ratios, along with chain extenders and isocyanates. This composite approach leverages the complementary properties of different polymer components to achieve both flexibility and chemical resistance that neither component could provide alone.
2Strength
If polyurethane polymers are used to provide structural strength, then strength is improved, but resistance to aliphatic hydrocarbon fuels deteriorates
Solution Approach 1:
The patent optimizes the chemical structure parameters by specifying polyester polyol with 60-80% adipate content and polyether polyol with 60-80% ether content, along with controlled molecular weights and ratios. These parameter changes create a polyurethane structure that maintains structural strength while introducing chemical resistance to aliphatic hydrocarbon fuels.
Solution Approach 2:
The patent uses chain extenders as intermediary compounds that bridge the polyester and polyether polyol segments, creating a hybrid structure that mediates between the structural requirements and fuel resistance requirements. The chain extenders facilitate the formation of a cross-linked network that provides both strength and chemical stability.
3Ease of manufacture
If general purpose polyurethane elastomers are used, then ease of manufacture is improved, but fuel resistance and hydrolytic stability deteriorate
Solution Approach 1:
The patent specifies precise parameter ranges for the polyols (adipate content 60-80%, ether content 60-80%, molecular weights) that can be achieved through conventional manufacturing processes. By defining clear parameter targets within standard manufacturing capabilities, the patent maintains ease of manufacture while achieving superior fuel resistance and hydrolytic stability through optimized composition rather than complex processing.
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 resulting polyurethane composition exhibits excellent resistance to aliphatic hydrocarbon fuels, including alcohol-containing fuels, and improved cold temperature snap-back characteristics, providing enhanced fuel resistance and hydrolytic stability for flexible fuel containers.
Implementation Method 1
A high molecular weight, thermoplastic polyurethane (or TPU) composition characteristically resistant to aliphatic hydrocarbon fuels, where the polyurethane composition is adapted for use as an aliphatic hydrocarbon fuel barrier in the construction of flexible fuel containers, and the polyurethane is the reaction product of as poly(diethylene adipate) glycol reacted with a non-hindered diisocyanate and an aliphatic chain extended
Implementation Method 2
The resulting polyurethane composition exhibits excellent resistance to aliphatic hydrocarbon fuels, including alcohol-containing fuels, and improved cold temperature snap-back characteristics
Data Source
AI summary
A high molecular weight, thermoplastic polyurethane composition characteristically resistant to aliphatic hydrocarbon fuels, where the polyurethane composition is adapted for use as an aliphatic hydrocarbon fuel barrier in the construction of flexible fuel containers, and the polyurethane is the reaction product of a poly(diethylene adipate) glycol reacted with a non-hindered diisocyanate and an aliphatic chain extender.