Cellulose acetate is quite light, the density is very low. But cellulose acetate is reasonably hard as a thermoplastic (similar to high-impact ABS - not as hard as PC). It is glossy and has good optical transparency (up to 90%). Cellulose acetate is both a good thermal insulator and a good electrical insulator. Additionally, cellulose acetate is antistatic so that dust hardly sticks to it. Acetylated cellulose also has some special mechanical properties. For example, it has low susceptibility to stress cracking (dependent on composition), and can polish itself during usage. Scratches on the surface disappear automatically. However, cellulose acetate absorbs water easily, leading to the instability of dimension. Cellulose acetate can be attacked by concentrated acids, alkalis and other chemical reagents. And cellulose acetate is not resistant to UV. Acetylated cellulose has wide range of utilization. It is used in cosmetic containers, tool handles, spectacle frames and so on. Cigarette filters are by far the largest use of CA.

Fundamental Information

Figure 1. Cellulose Acetate is used as cigarette filters

Cellulose is one of the main structural polymers in plants (specifically that of wood or cotton). These natural fibers are treated with acids to produce a resin, a process called 'esterification'. Cellulose acetate (CA), cellulose acetate butyrate (CAB) and cellulose acetate propionate (CAP) are three common cellulose materials. CA combines toughness, transparency and a natural surface texture. Some cellulose resins are biodegradable allowing their use for envelopes with transparent windows that can be disposed of as if they were paper alone.

Environmental Notes

Cellulose acetate is a natural, renewable cellulose-based polymer, which can therefore qualify as biopolymers. The processing, however, involves chemicals that create a problem of disposal. Most cellulose-based polymers burn easily, requiring protection from naked flame. Some are biodegradable.

Recycle Mark

Effect of Composition

The viscosity increases with increasing acetate contents: 44-48% - low viscosity, 52-56% - medium viscosity and 56-61% - high viscosity. To enable thermoplastic processing, 15-20 wt% plasticizers are added to the resin. Modulus and tensile strength decrease linearly with increased plasticizer content. Heat distortion point decreases and melt flow rate and creep tendencies under load increase with increased plasticizer content.

Typical uses

Cosmetic containers, tool handles, steering wheel covers, spectacle frames, pens, packaging, toys and models, brush handles. Low viscosity: textile production and printing inks, medium viscosity: coatings and adhesives (molding grades) and high viscosity: safety- and electro-insulation films. Cigarette filters are by far the largest use of CA.

Other notes

CA cannot be mixed with either CAP or CAB.

No warranty is given for the accuracy of this data