Oxidized Cellulose Dissolution in Polar Aprotic Solvents
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Solution Overview
Problem
Traditional cellulose dissolution processes are cumbersome, expensive, and require harsh conditions, leading to degradation and limited solubility in common solvents, which hinders the full exploitation of cellulose potential.
Innovation Solution
A process involving the use of a polar aprotic solvent and a salt under an inert atmosphere, where cellulose is swelled and then contacted with the salt at specific temperature ranges to form a stable modified cellulose solution, minimizing degradation and maintaining the molecular weight and degree of oxidation of the cellulose.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional cellulose dissolution processes are used, then cellulose can be dissolved, but the process becomes cumbersome and expensive with harsh conditions leading to degradation
Solution Approach 1:
The patent changes the chemical parameters by using oxidized cellulose with specific degree of oxidation (0.3-1.0) and dissolving in polar aprotic solvents with specific boiling point ranges (175-205°C), transforming the dissolution conditions from harsh traditional methods to controlled chemical parameters that prevent degradation while maintaining effectiveness
Solution Approach 2:
The patent applies inert atmosphere by conducting the dissolution process under nitrogen or other inert gases, eliminating oxygen that would cause oxidative degradation of cellulose, thus resolving the contradiction between effective dissolution and prevention of harmful degradation
2Reliability
If traditional cellulose dissolution processes are used, then cellulose can be dissolved, but the process requires high thermal treatment and excessive physical manipulation contributing to degradation
Solution Approach 1:
The patent optimizes temperature parameters by dissolving oxidized cellulose at controlled temperatures below the solvent boiling point after initial swelling, avoiding excessive thermal treatment that causes degradation while maintaining dissolution effectiveness through precise temperature parameter control
3Reliability
If traditional cellulose dissolution processes are used, then cellulose can be dissolved, but lengthy treatment periods cause degradation of oxidized groups
Solution Approach 1:
The patent applies preliminary action by first swelling the oxidized cellulose in the polar aprotic solvent before adding salt to initiate dissolution, and by conducting oxidation beforehand to create cellulose that dissolves more rapidly, thus reducing the lengthy treatment period that would otherwise cause degradation of oxidized groups
4Ease of manufacture
If cellulose is dissolved in common solvents, then the process is simpler, but solubility is limited
Solution Approach 1:
The patent creates a composite dissolution system by combining oxidized cellulose with polar aprotic solvents and adding specific salts (lithium halides, sodium halides, potassium halides) at controlled concentrations (0.1-3% by weight), forming a composite system that dramatically increases cellulose solubility in otherwise simple processes
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
This process effectively dissolves cellulose with minimal degradation, allowing for the formation of stable modified cellulose solutions with preserved molecular weight and oxidation levels, suitable for various applications including medical devices and bioactive agent encapsulation.
Implementation Method 1
forming a mixture by contacting a modified cellulose with a solvent under an inert atmosphere to form a swelled modified cellulose
Implementation Method 2
contacting the swelled modified cellulose with a salt under the inert atmosphere to form a modified cellulose solution
Data Source
AI summary
A microsphere and method for forming the same are disclosed. The microsphere includes modified cellulose and at least one of a visualization agent, a magnetic material, or a radioactive material.