Multi-Block Copolymer Composition for Phase Domain Size Control
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Solution Overview
Problem
Existing multi-block copolymer compositions exhibit large phase domains that negatively affect their properties, particularly in medical applications, due to uncontrolled polymerization conditions and differing reactivity of monomers, leading to undesirable blockiness and phase separation.
Innovation Solution
Control the polymerization conditions by adjusting the addition rate and temperature of phosgene to enhance the incorporation of aliphatic diol monomers relative to aromatic diol monomers, resulting in smaller domain sizes and potentially a single-phase copolymer composition with desired glass transition temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional polymerization conditions are used with multi-block copolymers, then phase separation occurs forming large discontinuous domains, but this morphology is difficult to control and results in undesirable properties
Solution Approach 1:
The patent applies parameter changes by controlling the addition rate and temperature of phosgene during polymerization. Specifically, maintaining temperature at 20-25°C and using controlled addition rates prevents excessive blockiness and achieves desirable phase domain sizes (1-10 μm), resolving the contradiction between manufacturing precision and ease of operation.
2Strength
If the copolymer composition contains large discontinuous phase domains, then phase separation is enhanced, but this adversely affects mechanical properties and radiopacity
Solution Approach 1:
The patent uses parameter changes to control phase domain morphology into the desirable 1-10 μm range through controlled polymerization conditions. This resolves the contradiction by achieving both improved mechanical properties and acceptable phase separation morphology simultaneously.
Solution Approach 2:
The patent creates a composite material system where multi-block copolymers with controlled morphology are combined to achieve both desirable mechanical properties and radiopacity. The controlled phase domain structure allows the material to benefit from phase separation-enhanced mechanics while avoiding the adverse effects of large domains.
3Productivity
If phosgene is added rapidly to enhance polymerization speed, then productivity increases, but this leads to uncontrolled blockiness and large phase domains
Solution Approach 1:
The patent applies periodic action through controlled addition of phosgene at specific rates while maintaining temperature control. This periodic, controlled addition rather than rapid continuous addition achieves both acceptable productivity and desirable blockiness control, preventing excessive phase separation.
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 controlled polymerization process reduces phase domain sizes, enhances mechanical properties, and allows for the formation of single-phase copolymers with improved radiopacity and biocompatibility, suitable for various medical devices.
Implementation Method 1
copolymers have been developed for medical applications... copolymerization of a selected combination of comonomers resulted in a desirable balance of properties
Implementation Method 2
certain copolymer compositions exemplified by those described in Example 21 of U.S. Pat. No. 9,416,090 have a morphology characterized by undesirably large discontinuous phase domains
Data Source
AI summary
Methods of making multi-block copolymer that reduce the tendency for large phase domains to form provide copolymer compositions that are useful for various applications, including the manufacture of medical devices.