We’ve seen the rise of bioplastic nowadays. It’s not something bad, of course, but we rarely use it for the “bigger” objects (I’ve only seen bags, I haven’t seen bioplastic red solo cup or something) because of their low heat resistance. 

That is, up until now. Collaborative research between JAIST and U-Tokyo has successfully developed the white-biotechnological conversion from cellulosic biomass into the aromatic polymers 

Whoa, whoa what’s that, you may ask? Simply put, the collaboration has developed the highest thermodegradation of all the plastics reported ever. 

Establishing sustainable environment needs new energy-efficient materials using biomass. Right now, the lightweight plastics made from renewable biomass are necessary for developing a circular economy.  

However, currently available bioplastics (PLA, PHA, PA11, etc) are mostly aliphatic, meaning it doesn’t have good thermostability. That leaves little space for other, further applications. 

Aromatic backbone-based polymers are widely considered for their high heat-resistance (such as Zylon, Celazole, Kapton, etc). Unfortunately, developing them from biomass into something else are rare due to difficulty in controlling their structure. 

Prof. Ohnishi and his research team in U-Tokyo produced two specific aromatic molecules from kraft pulp. The team then went on to process things that involve a lot of chemical reactions here and there. In the end, they were able to develop thermoresistant film. 

They also incorporated some chemicals to dramatically increase the heat-resistance. And voila, the highest thermostable plastic on record. 

Researchers have developed organic plastic superior in thermostability (over 740 °C). They used inedible biomass feedstocks without using heavy inorganic fillers and as a result, the plastic is lightweight. 

That innovative molecular design of ultra-high thermoresistance polymers is good. How so? It can contribute to establishing a sustainable carbon negative society, and energy conservation by weight saving. 

Bioplastic that’s UV-resistant 

University of Oulu’s Research Unit of Sustainable Chemistry has developed a new synthetic bioplastic. Unlike traditional carbon-based plastics or other bioplastics, this one protects from the sun’s ultraviolet radiation. 

Researchers at the university developed a biomass-based copolymer. Inside, there’s a structure can effectively prevent UV radiation from passing through a film made from the material. 

As for transparency, the bioplastic is still pretty good. Also, the airtightness of the material is 3-4 times that of standard PET plastic. Bioplastic is getting a lot more innovative and advanced now and it’s definitely a good thing. 

And it’s an evidence that it is possible to develop bioplastics that have better properties than conventional plastic we have today. 

Maybe later, the new environmentally friendly bioplastic can transform into packaging material. And not just any packaging alternative, it also has protective properties (from direct sunlight). 

Electronics or high- tech applications such as chassis materials for printed electronics also require advanced material protection features. 

The biopolymer developed in Oulu is entirely biomass based. The raw materials used in production are hydroxymethylfurfural (HMF) and furfural, which are biorefinery products derived from cellulose and hemicellulose.  

By chemically linking these the researchers were able to create copolymer parts with both bisfuran and furan-like structures. The researchers have filed a patent application for this method. 

Hopefully, we can get more bioplastic stuff later or sooner. 

Skepticism regarding bioplastic 

An article I found on Plastics Today questioned the efficiency of biomass in producing plastics. The writer said that biomass contains CO2, since plants are massive storehouses for this gas. So, how much CO2 will be released into the atmosphere in processing biomass? 

We know that today we’ve got better technology such as carbon upcycling. But the writer doubts that it really helps. 

According to a blog from Columbia University published in 2011 there are several ways to use biomass. Scientists seeking to replace plastics derived from natural petroleum and natural gas with natural biomass has a purpose to reduce greenhouse gases. But they may be barking up the wrong tree.  

“In 2010, a group of prominent scientists wrote to Congress explaining that the notion that all biomass results in a 100% reduction of carbon emissions is wrong. 

“Biomass can reduce carbon dioxide if fast-growing crops are grown on otherwise unproductive land; in this case the regrowth of the plants offsets the carbon products by the combustion of the crops,” wrote the author of the blog, Renee Cha. 

In the case of turning biomass into plastic, plant regrowth is important. That way, it can offset carbon emissions from the fossil fuels used to harvest, transport and turn the biomass into plastics via an industrial process. 

Upcycling carbon dioxide 

Cutting and harvesting various types of crops and grasses release the sequestered CO2 into the atmosphere. The article writer argues that despite all that, scientists now think they have figured out how to recycle waste CO2 back into plastic by carbon upcycling. 

An article in ScienceAlert.com in 2018 notes that it’s been “clear for a while now that that there’s too much carbon dioxide in the Earth’s atmosphere.” As a result, “scientists have come up with a new plan for dealing with all this excess CO2—converting it into plastic.” 

The Plastics Today writer went on saying that a real circular plastics manufacturing process happens with this. We grow plants, grasses and crops to harvest, transport and process into plastic, which releases a lot of “waste CO2” into the atmosphere. 

And then, we have to capture that waste CO2 and turn it into plastic while at the same time scientists are turning the biomass into bioplastics. 

“Perhaps if we didn’t harvest all of those grasses, crops and other biomass products to make bioplastic, we’d have less CO2 in the atmosphere. Would making plastic from waste CO2 be any greener than making it from natural gas or natural petroleum?” wrote the writer. 

Some people are just not buying it 

David Nield, author of the ScienceAlert article, notes that carbon upcycling “is the most efficient method yet that scientists have devised for converting carbon dioxide into ethylene, the raw material used to make the most commonly used plastic, polyethylene.  

“And it brings the possibility of a practical CO2-to-plastic conversion system a whole lot closer.” 

However, the writer insists that bio-based plastics will have the upper hand than the conventional, petroleum-based plastics. They stated that petroleum and natural gas to make plastic is still considered natural materials. 

“Given that we live in a carbon-based world and that CO2 is essential to all life on the planet, using plants and biomass that sequester carbon in an effort to reduce carbon dioxide may not reduce this gas as much as anticipated,” wrote the author. 

I guess some people simply don’t buy bioplastic. I don’t know if these people are just playing the devil’s advocate or they outright deny bioplastic’s potential advantage. What do you think, though?  

 

Sources

https://www.sciencedaily.com/releases/2020/10/201021111609.htm  

https://phys.org/news/2020-02-bioplastic-uv.html  

https://www.plasticstoday.com/sustainability/creating-plastics-biomass-really-green-idea