Cellulose Coagulation Conditions for Low-Crystallinity Molded Bodies
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Solution Overview
Problem
Existing cellulose manufacturing methods, such as the viscose method, involve numerous steps, require extensive equipment, generate hazardous gases, and pose environmental and safety challenges, and struggle to produce cellulose molded bodies with controlled crystallinity and xylose concentration.
Innovation Solution
A manufacturing method that dissolves cellulose material in a cellulose-dissolving agent comprising tetraalkylammonium acetate and an aprotic polar solvent, followed by molding and drying, allowing for the production of low-crystalline cellulose molded bodies regardless of xylose concentration, with controlled crystallinity through adjustments in solution conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the viscose method is used to manufacture cellulose, then cellulose can be produced, but the process involves numerous steps, requires extensive equipment, generates hazardous gases, and poses environmental and safety challenges
Solution Approach 1:
The invention extracts and eliminates the complex viscose generation steps from the cellulose manufacturing process. Instead of using the traditional viscose method with its multiple steps (alkali treatment, carbon disulfide sulfurization, aging, dilution), the patent directly dissolves cellulose in ionic liquid to form a cellulose solution, thereby removing the harmful intermediate steps and equipment requirements while maintaining reliable cellulose production
Solution Approach 2:
The invention changes the fundamental parameter of the dissolution medium from traditional solvents (which require viscose generation) to ionic liquid. This parameter change enables direct cellulose dissolution without the need for complex pretreatment steps, reducing equipment complexity while ensuring reliable cellulose recovery through subsequent coagulation
2Reliability
If the viscose method is used to manufacture cellulose, then cellulose can be produced, but the use of alkali solutions, acid solutions, and hydrogen sulfide gives rise to issues such as the need for exhaust gas and waste liquid treatment
Solution Approach 1:
The invention converts the traditionally harmful viscose generation process into a beneficial direct dissolution approach. By using ionic liquid, the process eliminates the generation of hazardous substances (hydrogen sulfide, alkali solutions, acid solutions) while maintaining effective cellulose dissolution and recovery, thereby converting a harmful process into a clean and beneficial one
Solution Approach 2:
The invention extracts and removes the harmful chemical agents (carbon disulfide, strong alkalis, strong acids) from the manufacturing process. The ionic liquid-based direct dissolution method eliminates the need for these hazardous substances while maintaining reliable cellulose production through a simplified process
3Ease of manufacture
If sulfurizing gases are present in the work environment due to processes such as sulfurization step, washing, and desulfurization, then cellulose can be processed, but it is essential for workers to take safety measures such as wearing protective clothing
Solution Approach 1:
The invention extracts and eliminates the sulfurization steps (which generate harmful sulfurizing gases) from the cellulose processing workflow. By using direct dissolution in ionic liquid followed by coagulation, the process removes the source of hazardous gases while maintaining ease of manufacture through a streamlined process that requires no protective clothing for workers
4Ease of manufacture
If a cellulose material with high xylose concentration is used to obtain low-crystalline cellulose fiber, then dyeability is improved, but safety standards for sanitary materials may not be satisfied due to distillation residue limits
Solution Approach 1:
The invention changes the crystallinity parameter through control of coagulation conditions (temperature, ionic liquid concentration) rather than relying on raw material composition. This allows production of low-crystalline cellulose with improved dyeability while using raw materials that comply with sanitary material safety standards by controlling xylose concentration in the final product
5Strength
If the degree of crystallinity of cellulose is increased to improve strength, then transparency and flexibility are decreased
Solution Approach 1:
The invention introduces dynamic control of crystallinity through adjustment of coagulation parameters (temperature, ionic liquid concentration). This allows the crystallinity to be dynamically optimized to achieve the desired balance between strength and transparency/flexibility, rather than being fixed by raw material composition
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
Enables the production of cellulose molded bodies with low crystallinity, improved solubility, fluidity, and flexibility, while complying with safety and environmental standards, and expanding the range of raw materials and applications.
Implementation Method 1
a cellulose material is dissolved with a mixed solvent comprising an ionic liquid of imidazolium salt and an aprotic polar solvent to form a cellulose solution
Implementation Method 2
the cellulose solution undergoes coagulation with an acid solution such as sulfuric acid
Implementation Method 3
the higher the degree of crystallinity, the more light is diffusely reflected and the more transparency is decreased
Implementation Method 4
the viscose undergoes coagulation with an acid solution such as sulfuric acid
Data Source
AI summary
Provided are a manufacturing method for a cellulose molded body, in which a low-crystalline cellulose molded body can be obtained by adjusting the molding conditions regardless of xylose concentration in constituent sugars of the cellulose material, and a cellulose molded body. Included are a cellulose dissolution step of dissolving a cellulose material in a cellulose-dissolving agent to obtain a cellulose solution; a molding step of discharging the cellulose solution into an aqueous molding solution at 10 to 70° C. comprising 20 to 50% of the cellulose-dissolving agent to produce a wet molded body; and a drying step of washing and then drying the wet molded body to obtain a cellulose molded body.