After drying the bioplastic tests overnight it was clear that the starch based one was really interesting and much more transparent than I was able to create on my own at home during last year’s experiments. I still felt though that I would have a problem trying to get in onto my fabrics in a controlled way. (see image above – starch bioplastic is the clear/ white material in the lower petri dish. The top dish contains the (green coloured) agar bioplastic.)
So we decided that we should focus our attention solely on the algae based bioplastics. The samples that we had created the day before had a lovely translucency; like looking through the see through coloured plastic sweet wrappers (see image above). Unfortunately the agarose mix without the glycerol was very fine and delicate after drying out. It was brittle, prone to tearing easily and very hard to scrape off the bottom of the Petri dish. So our final experiment yesterday was to test what would happen if we added glycerol to the algarose mix. To heighten the effect Conor decided to add 4ml of glycerol to the mix.
After drying in the oven at 65degrees from 12 until 6pm and being left on the bench overnight both algae samples were dry. However as earlier stated the algarose without the glycerol was deemed unsuitable as a material for this project. The sample with added glycerol was much more interesting and when pulled slightly had a little give or stretch in the material. It was however a little sticky to the touch though.
So on day two of our sampling programe Conor decided to work with the algarose recipe and by adding 1, 2 and 4ml of glycerol test to see which if any had more workable properties.
So we made up 3 sample batches. Before I poured the solubulised liquid into the Petri dishes I added small strips of different types of fabric to the bottom of the Petri dish. The fabric samples were a nylon fixed gauze used in screen printing, a nylon lycra. (see image below – left hand petri dish)
It was decided before continuing any further testing of the bioplastic with the various sculptural fabrics that it was best to see which if the recipes would work best.
Two other tests were undertaken as well on this day.
To simulate the way the fabric would be working in a sculpture lycra mesh netting was stretched over the petri dish and held in place by an elastic band. The warm (4ml glycerol) liquid painted onto the stretched fabric and set pretty quickly. As I was hoping to eventually layer up the material onto the fabric we decided to test this out by painting a second layer on top of the first. (see image above – right hand petri dish)
Finally as we had talked about the lack of flexibility with the normal algarose mix Conor suggested that if we could add bubbles to the liquid mix before it set the bubbles would create a cushion and matrix inside the material that could allow it to flex better. He suggested working with Alka selzer could give us the effect we were looking for.
So Conor crushed some of the tablet and put it on the Petri dish and pouring the slightly cooled down liquid algarose without the glycerol onto the powder. See image for result. He did something similar when he carefully added the remaining crushed tablet to the beaker of plain algarose over the sink. As he expected it bubbled and frothed up. Both samples were put into the oven to dry.
Results from bioplastic testing: day 2:
Tests with basic agar bioplastic recipe with 1ml glycerol – too brittle and inflexible
Tests with agar bioplastic recipe with 2ml glycerol – a little bit of give
Tests with agar biopastic recipe with 4ml glycerol – stretchy but a bit sticky