There are various types of plastic materials claim to be biodegradable, but many of them are not truth!

Photodegradable Plastics are early on considered as substitute for general plastic, it results from Petroleum-based plastics by adding chemical additives, and can gradually turn into microplastics while exposed to sunlight. However, this process does not change the molecular structure of plastic, the leftover will last in environment and cause no less damage to the environment as general plastics.

Instead of adding chemical additives, Disintegrable Plastics are formed through adding natural materials, such as starch, fiber, etc. It is only literally eco-friendly, those natural materials do not change the molecular structure of plastic as well, so it will result in the same consequence as Photodegradable Plastics.

So, what is biodegradable?

At this stage of science, biodegradable means compostable! It limits the biodegradable plastics to be defined as degraded by organisms in composting, the leftover in terms of water and carbon dioxide, it has to be harmless to the environment. The sources of biodegradable plastics are divided into two categories, which are bio-based compostable materials and petroleum-based compostable materials.

Among those biodegradable plastic materials, Polylactic acid (PLA) is the most popular option, it is bio-based and made of lactic acid which can be produced from crops such as corn, cassava, and so on. PLA products can be totally biodegraded in composting condition, as an ideal eco-friendly polymer, it comes from nature, it harmlessly returns to nature.

Aside from its biodegradable character, there are more features ensuring that PLA are favored:

First of all, PLA stays safe for food contact at high standard, its monomer is lactic acid which has been widely applied in the field of food production as food additive for yoghurt, condiment, etc.

Compared with petroleum-based monomer, it is safer while adopted as biomedical material for surgical suture, bone fixing, etc.

Second of all, PLA is low-carbon material, which means throughout producing process, delivering, storing and applying, its carbon dioxide consumption and carbon dioxide emission stay at comparatively low level to other plastic materials. For example, in order to produce 1kg of PLA film, from the beginning of corn planting or cassava planting, it has to experience glucose extraction, lactic acid fermentation, polylactic acid polymerization, and polylactic acid producing processing, the total amount of carbon dioxide emission is about 1.274kg, but the emission amount for 1kg of PET mineral water bottle is 4kg, and 2.5 kg emission for 1kg of PP shampoo bottle.

Last of all, PLA is completely biodegradable, its end-product are only water and carbon dioxide.

The application of PLA covers a wide range, it can be used in producing disposables, such as film and cover for coffee cups, beverage straw, etc. Apart from that, PLA can also be seen in the field of daily necessity, 3D printing，synthetic fiber and many more.