What is PBAT and PLA?

itto Shells (phone cases) are made of bamboo fibre, PBAT and PLA. Bamboo fibre is self-explanatory, but what are all these alphabetical mambo jambo, you ask? Fear not, this is not a ploy to confuse consumers by stringing a few random letters together - though I can't deny that it feels that way at times, especially when there are businesses out there that omits important information which may affect decision making. 

Let us break it down for you: 

Summary

What is PBAT?

PBAT (Polybutyrate Adipate Terephthalate) is a fossil-based polymer, and therefore is not considered a renewal source. That said, PBAT is incredibly biodegradable. It is capable of breaking down completely when buried in soil through actions of microorganisms, such as fungi, algae and bacteria, and it does not release methane or toxic residues at all.  

Despite the fact that PBAT is made of non-renewable source, it is still a lot better than traditional plastic. This is because PBAT is designed to be fully biodegradable due to the presence of butylene adipate groups, while traditional plastic is designed to last as long as possible. In fact, PBAT was developed as part of the solution to combating plastic pollution. 

What is PLA? 

PLA (Polylactic Acid, or Polyactide) is a form of polyester that is made of lactic acid and lactide produced by fermentation of a carbohydrate source under controlled conditions. The carbohydrate source could be corn starch, sugarcane, or cassava. As PLA is plant-based, it is considered sustainable and renewal. It is currently one of the most used bioplastics in the world.

PLA is fully compostable in the controlled environment of a commercial composting facility. Many eco-friendly products available in the market today are made of PLA and are claimed by the businesses to be fully home compostable. This is only partially true, as PLA requires specific conditions (such as moisture and temperature) to properly biodegrade. PLA is home compostable, only if your home compost is able to reach a temperature of 60°C. This is achievable through hot composting. Read this blog by GreenSXM where they tested composting PLA at home. 

Despite its advantages of being renewable and compostable, do be mindful that if PLA is in a natural environment or landfill, it contributes to plastic pollution. As mentioned above, PLA can only biodegrade under specific conditions. The length of time required for PLA to break down outside of a composting environment remains debatable, as there as some articles that suggest it takes 80 years, while some suggests hundreds of years.  

Why mix PBAT with PLA?

PBAT is designed to break down fast - even faster than organics, such as banana skin (interesting, I know!). Ironically, the higher the plant-based content, the longer it takes to compost. So, PBAT is mixed with PLA to increase the speed of biodegradation.  

Further, PLA on its own is a rigid and brittle material. PBAT is added to PLA to increase the flexibility and strength of the overall material, to make it suitable for its purposes.

Final Thoughts  

We are aware that compostable phone cases made from bamboo fibre, PLA and PBAT are not the perfect solution to combating plastic pollution, but it is the best we have for now. We are on the lookout for a 100% renewable solution, and would love to hear from you if you are aware of any!