Polycarbonate Diol Composition for Flexible, Heat-Resistant Polyurethanes
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Solution Overview
Problem
Conventional methods for producing polycarbonate diols using 1,10-decanediol result in low production efficiency, high costs, and poor physical properties of polyurethanes due to inadequate consideration of aldehyde derivatives in the raw materials, affecting reactivity and properties of the resulting polyurethanes.
Innovation Solution
A method involving the polycondensation of 1,10-decanediol with an aldehyde derivative and a carbonate compound in a transesterification reaction, with specific catalysts and conditions to achieve a polycarbonate diol with a molecular weight of 250 to 5,000, improving reactivity and physical properties such as flexibility, chemical resistance, and heat resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polycarbonate diol synthesized from 1,6-hexanediol is used, then heat resistance and hydrolysis resistance are improved, but flexibility and low-temperature properties deteriorate due to high crystallinity
Solution Approach 1:
The invention changes the chemical structure parameter of the dihydroxy compound from 1,6-hexanediol to 1,10-decanediol, which has a longer carbon chain. This structural parameter change reduces the crystallinity of the resulting polyurethane while maintaining heat and hydrolysis resistance, thereby improving flexibility and low-temperature properties without sacrificing durability
Solution Approach 2:
The invention uses a composite approach by combining 1,10-decanediol with specific carbonate compounds (cyclic carbonate and chain carbonate) in controlled ratios. This composite raw material strategy creates a polycarbonate diol with balanced properties that achieves both high reliability (heat/hydrolysis resistance) and good ease of operation (flexibility/low-temperature performance)
2Ease of operation
If conventional production methods using 1,10-decanediol are used, then flexibility is improved, but production efficiency decreases and costs increase due to inadequate consideration of aldehyde derivatives
Solution Approach 1:
The invention performs preliminary action by pre-selecting and controlling the aldehyde derivative content in the 1,10-decanediol raw material before the polycondensation reaction. By specifying that the dihydroxy compound contains 0.01-5.0 wt% aldehyde derivative, the method prepares the optimal chemical environment in advance, ensuring both high flexibility and efficient production without requiring additional processing steps
Solution Approach 2:
The invention changes the parameter of aldehyde derivative content from an uncontrolled variable to a precisely controlled parameter (0.01-5.0 wt%). This parameter optimization simultaneously improves flexibility (by maintaining appropriate crystallinity) and production efficiency (by preventing side reactions and ensuring smooth polycondensation), resolving the contradiction between these two features
3Strength
If polycarbonate diol with high molecular weight is produced, then strength is improved, but reactivity during polycondensation and urethane polymerization deteriorates
Solution Approach 1:
The invention optimizes the molecular weight parameter of the polycarbonate diol to a specific range (250-5,000). This parameter control ensures that the polymer chains are long enough to provide strength but not so long that they become unreactive. The controlled molecular weight maintains both adequate strength and high reactivity for subsequent urethane polymerization reactions
Solution Approach 2:
The invention applies partial action by using moderate molecular weights rather than maximizing molecular weight. By producing polycarbonate diol with molecular weight in the 250-5,000 range rather than higher values, the invention achieves sufficient strength while preserving reactivity, avoiding the excessive molecular weight that would cause poor reactivity during polycondensation and urethane polymerization
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 produces polycarbonate diols with enhanced reactivity and physical properties, suitable for various applications including elastic fibers, synthetic leathers, and coating materials, offering improved industrial efficiency and performance.
Implementation Method 1
subjecting a compound represented by formula (A) containing from 0.01 to 1.0 wt% of an aldehyde derivative, a compound represented by formula (B), and a carbonate compound to polycondensation by a transesterification reaction in the presence of a catalyst
Data Source
AI summary
The present invention relates to a method for producing a polycarbonate diol, comprising subjecting a compound represented by the following formula (A) containing from 0.01 to 1.0 wt% of an aldehyde derivative, a compound represented by the following formula (B), and a carbonate compound to polycondensation by a transesterification reaction in the presence of a catalyst to produce a polycarbonate diol having a number average molecular weight of 250 to 5,000: HO-(CH2)10-OH (A) HO-R1-OH (B) (wherein in the formula (B), R1 represents a substituted or unsubstituted divalent alkylene group having a carbon number of 3 to 20, wherein the compound of the formula (A) is not included by the formula (B)).