High-Transparency Cellulose Acetate Film With Composite Plasticizers
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Solution Overview
Problem
Current methods for preparing cellulose acetate films face challenges such as high cost, oxidative degradation, yellowing, and poor mechanical properties due to direct melt processing, and small-molecule plasticizers' volatility, which affects flexibility and transparency.
Innovation Solution
A high-transparency, low-temperature processable cellulose acetate film is prepared using a composite plasticizer system comprising small-molecule and macromolecular plasticizers, along with a composite transparency agent, and a modification process involving glycerol and theanine, enhancing thermal stability and mechanical properties while minimizing discoloration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If direct melt processing is used to process cellulose acetate, then processing simplicity is improved, but oxidative degradation and yellowing occur leading to poor mechanical properties
Solution Approach 1:
The patent changes the processing temperature parameter by using a composite plasticizer system that lowers the glass transition temperature and melting temperature of cellulose acetate. This allows processing at lower temperatures (below 150°C) that prevent oxidative degradation while maintaining processing simplicity. The temperature reduction is achieved through the synergistic effect of small-molecule and macromolecular plasticizers.
Solution Approach 2:
The patent employs a composite plasticizer system consisting of both small-molecule plasticizers (e.g., triethyl phosphite, citrate esters) and macromolecular plasticizers (e.g., polyester plasticizers with molecular weight 800-8000). This composite approach provides both the temperature reduction benefits of small-molecule plasticizers and the stability benefits of macromolecular plasticizers, preventing oxidative degradation while maintaining ease of processing.
2Ease of manufacture
If small-molecule plasticizers are added to improve flexibility and reduce processing temperature, then processability is improved, but volatility occurs reducing flexibility over time
Solution Approach 1:
The patent merges small-molecule plasticizers and macromolecular plasticizers into a single composite system. The small-molecule plasticizers (triethyl phosphite, citrate esters) provide immediate flexibility enhancement and processing temperature reduction, while the macromolecular plasticizers (polyester plasticizers) provide long-term stability and prevent volatility. This combination allows the film to achieve both improved processability and stable flexibility over time.
Solution Approach 2:
The composite plasticizer system combines the advantages of both small-molecule and macromolecular plasticizers. The small-molecule components provide low-temperature processing and initial flexibility, while the macromolecular components ensure long-term stability and prevent the volatility issues associated with small-molecule plasticizers alone. This composite approach resolves the contradiction between processability improvement and flexibility stability.
3Stability of the object's composition
If macromolecular plasticizers are used to reduce volatility, then stability is improved, but processing temperature remains high causing degradation
Solution Approach 1:
The patent combines macromolecular plasticizers with small-molecule plasticizers to achieve both stability and low processing temperature. The macromolecular plasticizers provide volatility resistance and long-term stability, while the small-molecule plasticizers significantly lower the processing temperature through their ability to weaken intermolecular forces and reduce glass transition temperature. This merging resolves the contradiction by having each component contribute its specific benefit.
Solution Approach 2:
The composite plasticizer system leverages the complementary properties of macromolecular and small-molecule plasticizers. Macromolecular plasticizers ensure stability and resistance to volatility, while small-molecule plasticizers enable low-temperature processing by reducing intermolecular forces and glass transition temperature. Together, they achieve both stability improvement and processing temperature reduction, resolving the contradiction between these two requirements.
4Object-affected harmful factors
If glycerol is added as a natural plasticizer to improve biodegradability, then environmental friendliness is improved, but intermolecular forces are altered affecting pore structure and gas permeability
Solution Approach 1:
The patent uses glycerol as a natural plasticizer that modifies the physical parameters of the cellulose acetate film, including pore structure and gas permeability. Glycerol's polyhydroxy structure creates hydrogen bonding interactions that alter intermolecular forces and create a more open pore structure, improving biodegradability and environmental friendliness while controlling gas permeability 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 film exhibits improved transparency, reduced processing temperature, and enhanced mechanical properties with eco-friendly plasticizers, ensuring stability and safety.
Implementation Method 1
The flexibility and processability of cellulose acetate can be improved by lowering its glass transition temperature
Implementation Method 2
modifying cellulose acetate with theanine and glycerol; dissolving cellulose acetate in N,N-dimethylformamide or acetone; adding glycerol dropwise and react at 120-130° C. for 4-6 hours
Implementation Method 3
The melting temperature of cellulose acetate is close to its thermal decomposition temperature. Direct melt processing can easily cause oxidative degradation of cellulose acetate
Implementation Method 4
adding small-molecule plasticizers: These weaken the secondary bond interactions between cellulose acetate molecules, enhance the mobility of molecular chains, lower the melting temperature of cellulose acetate to prevent thermal decomposition
Implementation Method 5
Transparency agents primarily enhance the transparency of polymers. The principle involves adding high-efficiency transparency agents during polymer crystallization to ensure that the crystal size is sufficiently small—smaller than the wavelength of visible light
Implementation Method 6
a composite plasticizer system comprising small-molecule and macromolecular plasticizers, along with a composite transparency agent, and a modification process involving glycerol and theanine, enhancing thermal stability and mechanical properties
Data Source
AI summary
The invention discloses a high-transparency, low-temperature processable cellulose acetate film and its preparation method. The high-transparency cellulose acetate film comprises, by weight percentage, the following raw materials: 75-85 parts of modified cellulose acetate, 12-20 parts of plasticizer, 2-6 parts of transparency agent, where the plasticizer and transparency agent are both composite additives. The preparation process involves uniformly blending all raw materials, followed by uniform mixing and drying, extrusion, granulation, drying, and casting, to obtain a high-transparency cellulose acetate film. The cellulose acetate film prepared by the above method utilizes the synergistic effect of the specific plasticizer and transparency agent, which not only significantly reduces the processing temperature but also results in a film with high light transmittance and low haze. The film exhibits good extensibility and flexibility, excellent antibacterial properties, and the process is simple, time-saving, and efficient, making it suitable for large-scale industrial production.