1. moleculeoftheday
  2. Deforming Polylactic Acid (And playing with thermometer guns)

Deforming Polylactic Acid (And playing with thermometer guns)

By moleculeoftheday on September 27, 2006.

Inspired by Keith's comment on polylactic acid's tendency to deform under heat, and procrastination, I just did a quickie test of the heat-deformation characteristics of my polylactic acid bottle.

I took my PLA bottle and a cute little PET bottle I had lying around. I put some tap-hot water in the microwave and heated it up for awhile. After stirring to equilibrate the temperature, I measured it with my oh-so-cool noncontact thermometer, a Raytek Raynger ST-6, which I wouldn't own if it weren't for Jeffrey Steingarten's unintentional salesmanship (fortunately, by the time I got one, the model was about as dated as a PDP-8, so I think mine cost a few percent of what he paid). It was 168F/76C, so hotter than you'd ever encounter in a car (and maybe enough to even bring the PET above its Tg). I added a couple hundred mLs of water to each.

I love this thermometer. I am less thrilled with my ability to use available light.

I could never be a photographer because I'm too impatient/unskilled to get decent "before" shots. Deformation started immediately after addition of water. This is T+30 seconds or so

Another after shot. PET held up fine, eh? Deformation under gravity pretty much stopped here but the PLA was still deformable with manual pressure. T+2 minutes.

Back to work. See you tomorrow.

Tags
Polymers

More like this

Polylactic acid (Compostable plastic?)
This weekend I came across Biota brand spring water, which is the normal expensive kind of spring water (the kind where they make a point of saying where in the earth it came from rather than obfuscating the "municipal source" text). It was pretty good - maybe even one of the better waters I've had…
Friday Deep-Sea Picture (03/23/07)
Both Pictures from Igenious.org.uk  James Six (1731-1793) retired early from business to devote himself to the natural sciences. He is best known for the invention of the self-registering thermometer, first designed in 1780, which recorded the maximum and minimum temperatures reached. It was…
Deep-Sea Water Taste Test
Rick at Malaria, Bedbugs, Sea Lice, and Sunset recently reviewed Kona Deep awhile back and promised to send along a bottle to taste. Previously, I made a rather bold claim...Imagine yourself laying on a sandy beach. As you take in the supple views and iconic air, you reach for your multi-fruit,…
Friday Sprog Blogging: experimental results (milk + lemon juice).
This Friday we're reporting on one of the experiments we were looking forward to last Friday, the one in which milk is curdled. (We'll report on our experimental attempts to dissolve an avocado next Friday.) We started with a little over a cup and a half of whole milk, on the cold side (since it…

The Enviro-whiner trinity: Expensive, shoddy, deadly. "Shoddy" was the first recycled wool at the start of the Industrial Revolution. How well do you suppose that worked out? Also keep mungo and noils out of your fabric.

Do you want a kewl molecule? Icilin is a kewl molecule! Refereed literature plus US Pat. 3,821,221.