Borax and White Glue

Karen Lu, Kate Harris, Chloe Barker and Avery Holt

Materials

Borax Powder, Water, Elmer's Glue, 2 Spoons, 2 Cups, Food Coloring, 1 Plastic Baggie

Procedures

  1. First, pour 6 teaspoons of Elmer's glue* in a cup. Add 6 teaspoons of water to the cup containing the Elmer's glue and mix for 2 minutes using a plastic spoon.

  2. Add 2-4 drops of food coloring of your choice to the glue and water.

  3. Then, in a separate cup mix 1 teaspoon of Borax powder* and the 12 teaspoons of water*. Mix well for about 2 minutes.

  4. Next, slowly stir the glue mixture into the Borax solution in a bowl.

  5. Mix for 3 minutes.

  6. Put the slime in your hand and knead. (The more the slime is played with, the firmer and less sticky it will become.

  7. When done playing with the slime, place it into a plastic bag so the food coloring doesn’t stain any surfaces.

* does not have to be exact measurements

Safety Precautions

DO NOT SWALLOW THE BORAX POWDER, THE SLIME, OR THE GLUE.

Chemical Reaction

The mixture of Elmer’s Glue (PVA- polyvinyl acetate) with Borax (sodium borate) and water produces a putty-like material called a polymer, which is a long chain of molecules. Borax forms cross-links between the polymer chains in the polyvinyl alcohol. These are chemical bonds that hold the chains together, making the mixture less flexible and much thicker.

Chemical Equations

In water, the borax hydrolyzes to form a borate-boric acid buffer system:
The B(OH)4 – ion cross-links to the polymer chains as shown in Figure 2.
Because –OH groups of the borate ion can hydrogen bond with –OH groups of PVA polymer chains (see Figure 3). Hydrogen bonding is so weak that this could account for the ease of stretching and dripping, and the other observed properties.

Synthesis

In order to make the slime, the monomers become a polymer, which is a long chain of molecules. Since they are combining, this reaction is synthesis. We figured this out by analyzing the equation.

Endergonic and Endothermic

By observing the chemical reaction, you can feel the mixture becoming cold. Therefore the chemical reaction is an endothermic reaction, meaning it absorbs heat energy. Since it is absorbing energy, this makes the chemical reaction endergonic.

Everyday LIfe

The plastics used daily are made of polymers and so is the DNA of a human, DNA is a biopolymer (biological polymer). Teflon, used in non-stick pots and pans, and Kevlar, used in bullet-proof vests, are also examples of polymers.

Negative Aspects

When the slime becomes moldy, it is time to throw it out. Although borax is benign, it is not smart to swallow. The putty is also sticky and the food coloring can stain, so make sure to place the slime in the plastic baggie after you're done.

Polymers Demonstrated in Food

When a pile of freshly cooked spaghetti comes out of the hot water and into the bowl, the strands flow like a liquid from the pan to the bowl. This is because the spaghetti strands are slippery and slide over one another. After awhile, the water drains off of the pasta and the strands start to stick together. The spaghetti takes on a rubbery texture. Wait a little while longer for all of the water to evaporate and the pile of spaghetti turns into a solid mass — drop it on the floor and watch it bounce.
Many natural and synthetic polymers behave in a similar manner. Polymers are made out of long strands of molecules like spaghetti. If the long molecules slide past each other easily, then the substance acts like a liquid because the molecules flow. If the molecules stick together at a few places along the strand, then the substance behaves like a rubbery solid called an elastomer. Borax is the compound that is responsible for hooking the glue’s molecules together to form the putty-like material.