Basic Recipe for Agar Bioplastic

Agar bioplastic original basic recipe:

100 ml water

10,0 g agar

1,5 g glycerine

Method:

1. Sterilize all surfaces and utensils with ethanol.

2. Gather and weigh ingredients according to above recipe.

3. Mix all above ingredients in pot, stir until no clumps remain.

4. Heat to 95°C or until it starts to froth. Scoop out any froth with a spoon.

5. Pour or scoop substance into sterilized petri dishes and allow to cool and dry.

Results:

The consistency was like apple sauce and not pourable. After drying, the material was brittle and gritty as well as opaque and yellow.

Variable Agar

How does the amount of agar used influence the consistency and characteristics of the end product?

Basic Recipe with variable Agar:

100 ml water

1,5 g glycerine

Variable Agar: 15 g, 10 g, 5 g, 2,5 g, 1 g

We processed the ingredients according to the method described above.

Results:

For 15 g of Agar, the consistency was like thick apple sauce and not pourable. After drying, the material was very brittle and completely opaque. Increasing the agar did not seem to take the material in the right direction.

Reducing the agar produced a more liquid, pourable material. After drying, the product was more transparent but still fairly breakable.

One gram of agar produced a very pourable liquid that remained transparent after drying.

We noticed that mold grew on many of the surfaces, presumably during the drying process.

Addition of Ethanol

We tried to reduce the formation of mold during the drying process by incorporating ethanol.

Recipe:

10 g agar

1,5 g glycerine

100 ml water

Control batch: Sterilize utensils and petri dishes with ethanol as usual.

Batch 2.2: Pour a visible layer, about 1 mm thick, of ethanol into the petri dish, and scoop mixture on top. 

Batch 2.3: Scoop mixture into petri dish, then pour a layer of ethanol on top.

Batch 2.4: Add 3 g of ethanol into the mixture before scooping into petri dish.

Results:

The control batch did not get moldy this time. It does not seem necessary or desirable to add ethanol as in batches 2.2 to 2.4.  Simply work as cleanly as possible, disinfect utensils, and hope for the best.

Variable Pectin

During our research, we came upon a recipe that includes pectin in addition to the other ingredients. We decided to test it.

How does the amount of pectin used influence the consistency and characteristics of the end product?

Basic Recipe with variable pectin:

100 ml water

1,5 g glycerine

2,5 g agar

Variable pectin: 6 g, 3 g, 1,5 g, 0,75 g, 0,375 g

We processed the ingredients according to the method described above. We poured a very thin layer of liquid into the petri dishes to produce a thin foil.

Results:

Adding 6 g of pectin produces a stiff, dry foil that is very tear-resistant. It is slightly stretchable but not elastic. Few slight stretch-marks remain after stretching.

3 g of pectin produces a more flexible, dry foil that is still tear-resistant. It is slightly stretchable but not elastic. More stretch-marks remain after stretching.

1,5 g of pectin produces a smooth, dry, flexible foil. It feels more like plastic.

0,75 g of pectin produces a slightly rubbery foil that feels sticky but does not leave any residue. It tears more easily than the batches with more pectin.

0,375 g of pectin produces a thin, transparent foil. The foil is very flexible and only slightly stretchy but not elastic.

Variable Glycerine

How does the amount of glycerine used influence the consistency and characteristics of the end product?

Basic Recipe with variable glycerine:

100 ml water

0,375 g pectin

2,5 g agar

Variable glycerine: 7,5 g, 3,75 g, 1,5 g

We processed the ingredients according to the method described above. We poured a very thin layer of liquid into the petri dishes to produce a thin foil.

Results:

Reducing the amount of glycerine produces a very durable, dry, transparent foil that makes a slight crackling sound.

Increasing the amount of glycerine produces a less durable foil with a slightly sticky surfaces that feels elastic until it tears.

Final Recipe

We chose the following recipe to produce a thin, flexible yet durable film:

0,375 g pectin

2,5 g agar

1,5 g glycerine

100 ml water

Aesthetic Use

For an aesthetic application, we wanted to use our biomaterial in conjunction with light. For this purpose, we cut out circles from the dried foils and wrapped 2-3 around each LED light of the fairy lights. The fact that the foils are colored and transparent creates a cozy and colorful play of light und beautiful shadows.

Application Possibilities

Since our bioplastic is a foil, the area of application is very big, as plastic foils can be used almost anywhere. However, we have divided the scope of application by distinguishing between practical and aesthetic, decorative applications:

Practical application:

This product can be used whereever a foil is used in conjunction with paper. For optimal recycling, conventional foil would have to be separated from the paper and disposed separately. The biodegradable foil can be disposed of with the paper waste.

- Envelopes with window

- Covers for books

- Bags for bread in the supermarket

- All kinds of paper packaging with viewing window: cornflakes, muesli, etc.

However, the film should not come into contact with liquids or moist foods, as the film absorbs water and then becomes unstable and tears easily.

Aesthetic application:

Even in the aesthetic field of application, the film should not come into contact with water or liquids.

- Lampshades, fairy lights, indoor light installations

- (hair-) jewellery, for example earrings

- Interior design, colored cladding of glass panes

- Furniture, showcases, glass tables, etc.

Conclusion

The development of DIY biodegradable polymers is a crucial challenge in today's world. This bioplastic, composed of simple and readily available ingredients—agar, pectin, glycerine, and water—has numerous potential applications.

We envision a range of practical and decorative uses, such as book covers, lampshades, jewelry, and packaging. The bioplastic is flexible and durable, and can be cut into any imaginable shape. It can also be dyed and enhanced with additions like glitter. Moreover, it could serve as a binding agent in composite materials when combined with natural fibers or fabrics.

Working and experimenting in the laboratory was a highly instructive experience. Our process included both successes and failures, which only motivated us further. We are very satisfied with our result, particularly because we have produced a material that can be utilized in so many ways.

Finally, we would like to thank Danny Ott for his help and input in the Biolab.

Studio photos