Polycarbonate Polymer with Siloxane Repeat Units for Degradability
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Solution Overview
Problem
Existing polycarbonate polymers lack efficient degradability and surface modification, limiting their applications in films and coatings with low surface energy.
Innovation Solution
Development of polycarbonate polymers with non-aromatic cyclic groups bonded via carbonate linking groups, incorporating substituents with siloxane repeat units, which enhance degradability and surface properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing polycarbonate polymers are used, then structural stability is maintained, but degradability is insufficient and surface energy modification is limited
Solution Approach 1:
The patent combines polycarbonate backbone structure with siloxane repeat units to create a composite polymer material. The siloxane-containing substituent is incorporated into the polycarbonate structure, creating a composite material that exhibits both the structural stability of polycarbonate and the degradability and surface energy properties of siloxane groups. This composite approach resolves the contradiction by integrating two material systems with complementary properties.
Solution Approach 2:
The patent introduces siloxane repeat units as substituents at specific locations on the polycarbonate structure (attached to non-aromatic cyclic groups). This local modification allows the polymer to maintain its overall structural stability while gaining degradability and surface energy characteristics at the modified sites. The local quality principle enables simultaneous achievement of stability and adaptability through targeted structural modification.
2Reliability
If high concentration of carbonate linking groups is used to improve degradability, then thermogravimetric mass loss onset temperature decreases, but polymer structural complexity increases
Solution Approach 1:
The patent systematically varies the concentration of carbonate linking groups and siloxane repeat units to optimize degradability. By controlling the molar percentage of carbonate linking groups (at least 85 or 90 mol %) and adjusting the number of siloxane repeat units (m ≥ 1), the patent achieves desired thermogravimetric mass loss onset temperatures (220-300°C) while managing structural complexity through parameter optimization rather than fundamental structural redesign.
3Adaptability or versatility
If siloxane repeat units are incorporated to increase contact angle with water, then surface energy is reduced, but manufacturing complexity increases
Solution Approach 1:
The patent incorporates siloxane repeat units directly into the polymer structure during the polymerization process rather than as a secondary modification step. The siloxane-containing substituents are built into the polymer backbone or side chains during synthesis, allowing surface energy properties to be established in the primary manufacturing process. This preliminary action approach reduces the need for additional post-processing steps to modify surface 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 polymers exhibit improved degradability indicated by lower thermogravimetric mass loss onset temperatures and increased contact angles with water, making them suitable for low surface energy films and coatings.
Implementation Method 1
The inclusion of substituents having siloxane repeat units typically increases the (e.g. receding) contact angle with water relative to the same polycarbonate polymer lacking substituents having siloxane repeat units
Implementation Method 2
The high concentration of carbonate linking groups contributes to degradability of the polycarbonate polymer. Lower thermogravimetric mass loss onset temperatures can be indicative of improved degradability. In some embodiments, the thermogravimetric mass loss onset temperature is in the range from 220-300° C.
Data Source
AI summary
Polycarbonate polymers comprising non-aromatic cyclic groups bonded with carbonate linking groups are described. A portion of the non-aromatic cyclic groups comprise a substituent having siloxane repeat units. Representative formulas of the substituents having siloxane repeat units include —CH2—CH2—Si(R4)2—(OSi(R4)2—R5, and —CH[Si(R4)2—(OSi(R4)2)m—R5]—CH3; wherein m is the number of siloxane repeat units; and R4 and R5 are independently alkyl, aryl, aralkyl or aralkylene. The polycarbonate polymer C typically comprises a high concentration of carbonate linking group, for example in an amount of at least 85 or 90 mol % or greater N based on the total linking groups of the polymer. Also described are compositions comprising the polycarbonate polymer and methods of making.