Cellulose triacetate mechanical strength

The major features for advanced photo-systems relative to the base film are a small-size thrust cartridge and return inside the cartridge. These features require low core-set curl values and high mechanical strength. The cellulose triacetate (CTA), polycarbonate and PET materials currently used in the photographic industry are not able to satisfy these requirements. Some newly developed film materials, such as modified-PET and syndiotactic polystyrene, were also unable to satisfy such requirements. It is known that annealing films just below the Tg (BTA treatment) could reduce core-set curl tendencies. BTA treatments of... 

Microcrystalline cellulose II, like the cellulose I form, does not possess enough mechanical strength to be used as an HPLC-CSP Although its triacetate derivative, CTA-II, can be used as an HPLC support, it is not as useful a CSP as CTA-I (47). Ichida et al. (48) were able to improve on the properties of derivatized cellulose II by depolymerization, followed by coating on macroporous silica gel. In this manner, they created a number of new CSPs, the cellulosic CSPs, based on ester and carbamate derivatives of cellulose (see Table 2). 

A cellulose triacetate film has been used as a base film for a photo film. This triacetate film involves safety and environmental problems because an organic solvent is used in its production process. In addition, it has limits in mechanical strength and dimensional stability. Therefore, PET films are used partly as a substitute base film. However, when kept in the form of a roll and unrolled, PET films remain curled and this curl is difficult to remove. 

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