Thursday, 25 August 2016

STEP by STEP How to make silly putty

In this post I am going to show you How to make Silly Putty that is safe for children to make and play with. 

WARNING: Making Silly putty with borax might be really effective however, it is dangerous to breath in and when touched is a skin irritant!  This recipe is made WITHOUT the use of BORAX.



You will need:
  • GOGGLES
  • PVA GLUE
  • Starch Spray
  • 2 CUPS (clear cups or glasses are better as the children can see what's
    happening)
  • FOOD COLOURING (optional but adds to the fun)

ALWAYS WEAR GOGGLES WHEN DOING SCIENCE EXPERIMENTS.  It's
important to practice.  Also, wear aprons or get yourself a lab coat 

and be like a real scientist!  It will protect you and your clothes 
from being damaged.  This silly putty can stain and ruin, 
clothes, carpets, curtains etc.

Here's the video but scroll down for the written instructions...




STEP ONE

Put about 30 ml of PVA glue in a cup, mix a little food colouring in. 







STEP TWO

In another cup spray the starch spray until you have about 40ml of liquid starch settled in the container.

STEP THREE

Add the liquid starch to the PVA and colour and stir until it all binds together.




When it's all bound together it should be ok to pick up without it being a slimy mess.  You may need to remove excess liquid to achieve this .  It will then bounce like a ball when it's like this...



Or stretch, if you pull it really slowly so it looks like this..


What happens when you pull it fast?  It breaks cleanly apart rather than stretch right?


If you do chose to use borax, if you can get hold of any that is, just be careful as borax is a chemical and is a skin irritant so it's best to use gloves!


Liquid Starch is much safer to use, especially when doing this with young children!


What is a Polymer?  How is it so rubbery? 

Spaghetti is a very useful way of showing how and why polymers act the way they do. 

Spaghetti is made of long strands very much like the molecular structure of a polymer. 

When you boil up the spaghetti it runs like water, but then you take it out of the water and the starch makes it sick together and feel a bit sticky. 

Leave it a bit longer and you can bounce it!  This is due to the starch in the pasta. 

Why is spaghetti such a good example?

It is a great example because the molecules in the crazy putty are a linear polymer.  Which means the molecules are all in a line rather than branching.  Linear in this sense does not mean a straight line but one like cooked spaghetti that curls about.

Something else I like to do when there are plenty of people about to join is, is to make a model of a polymer using HUMANS!!

Ask at least 5 to stand in a row holding hands.  Now they are like a linear polymer molecule.  It's that simple.

You can try adding the PVA glue to the starch liquid instead of the start to the PVA glue...






OTHER POSTS THAT TEACH KIDS ABOUT POLYMERS...
















                   


HOW TO MAKE MAGNETIC PUTTY - and   a video of how magnetic putty works!






















First posted 5 August 2011 - Updated 25 August 2016

2 comments:

  1. Is starch spray something you would buy for doing laundry? Sorry to be dim, but I've never heard of it :/

    ReplyDelete
  2. I ordered 5 sets of scrubs in all different colors. I got blue, purple, green, wine and grey. The figs scrubs wash perfectly, come out wrinkle free from the dryer, and hold their color nicely.

    ReplyDelete