Water meets cellulose: Environmentally friendly plastic made from hydroplastic polymers
27.10.2021
The production of plastic is often not yet particularly sustainable – this may threaten the environment and human health. This is now set to change: Researchers at the University of Göttingen have developed a new method to create environmentally friendly bioplastics from renewable raw materials. In this process, a new type of hydroplastic is processed and reshaped with water.
Prof. Kai Zhang is the lead author of the study. In this interview with K-MAG he explains how the new polymers are created, what the advantages of the so-called hydrosetting method are, and forcasts the trends of sustainable plastics manufacturing.
Prof. Zhang, what is the problem with the conventional production of polymers?
Kai Zhang: The conventional production of polymers has the problem that the monomers of the polymers usually originate from petrochemicals, such as crude oil and gas, which are not sustainable.
Another problem is that the shaping of polymers usually involves complex and expensive devices as well as the harsh conditions such as high temperature, high pressure or curing processes involving oxygen exclusion.
Which material do you use for your new polymers and why this one in particular?
Zhang: We use cellulose cinnamate for our new polymers. Cellulose cinnamate is well suited because cellulose, the main raw material, is available as the most common organic compound on earth. In addition, the cellulose chain contains many hydrogen bonds that enable the polymer to absorb water, so it can be used as a hydroplastic after appropriate chemical modification.
What is the advantage of the new polymers?
Zhang: One advantage of the new polymers include the major raw material, cellulose, as the most abundant organic compound, is readily available on earth. The usage of cellulose as raw material for plastics makes it sustainable. Furthermore the easy processing technology as hydrosetting of the new polymer into diverse shapes by using water and air-drying, is simple, very cost-efficient and does not require much energy input, which makes it an eco-friendly plastic. The polymer can be shaped repeatedly by the facile hydrosetting method, which will highly prolong the shelf-life and usage time of such plastics, instead of simple throwing-away or deposition. The excellent mechanical properties of the new polymer ensured its application in various scenarios, which is also beneficial for their repeatable usage.
Exhibitors and products around Raw materials and auxiliaries:
- Bioplastics, biobased
- Bioplastics, cellulose based
- Bioplastics, Certifications/Standards
- Cellulose acetate, secondary (CA)
What applications is the new polymer intended for?
Zhang: We envisage a wide range of applications of the new polymer in the future and it should generally suit many scenarios where thermoplastic and thermosetting materials are applicable. In particular, our polymer materials as hydroplastics are promising to be used in scenarios where they do not need to have much contact with water, for example electrical and electronic goods, consumer and institutional products, and also for some industrial machineries. As specific examples, hydroplastics can be used for packaging that is currently a huge market for plastics, especially those products that usually stored in dry environments, such as clothes, papers, rice, cookies, tea, coffee, spices, dried fruits and nuts as well as oily or non-polar products. If used in multilayer design, it is also possible to use hydroplastics as packaging materials for liquids that contain water, such as juiceor even pure water. Moreover, hydroplastics together with elaborate product design can also be used for textiles, medical and healthcare, automotive, furniture and even aerospace, for example for armrests.
What makes the new manufacturing method sustainable?
Zhang: The hydrosetting method for the shaping of plastics can be applied with the usage of water, which do not need expensive and complex machine or harsh conditions such as high temperature, high pressure, or curing processes involving oxygen exclusion. Thus, the hydrosetting method is cost-efficient, energy-saving and sustainable. It can also be used repeatedly for the shaping of the hydroplastic polymer. Thus, the polymer can be shaped into diverse shapes for multiple times with this hydrosetting method. Therefore, hydrosetting is a sustainable manufacturing method for hydroplastics.
How do you think research into sustainable plastics orpolymers will develop in the next few years?
Zhang: In my opinion, researchers worldwide will devote more efforts to the sustainable plastics as the harming effects of plastics to the environment and human health are well known now. Future development of plastics will focus more on the use of renewable resources such as carbohydrates, carbon dioxide, and vegetable oils instead of petrochemicals as raw materials for the production of plastics. Research is being done on methods for more efficient recycling and reuse of plastics, such as efficient enzymes for depolymerizing polymers or transferring plastics into other useful forms of resources. In general, I think the focus will be on new cost-effective, environmentally friendly and sustainable methods. The technical innovations that enable research results to be transferred from the laboratory to the factory are being further developed.