What happens when you mix polyvinyl alcohol and borax?
What happens when you mix polyvinyl alcohol and borax?
In this experiment, a polymer (polyvinyl alcohol) chemically reacts with borax to form a crosslinked polymer network. Individual polymer chains are formed by covalent bonds, which are strong bonds. In making slime, the individual polymer chains are bound together by weak hydrogen bonds.
Is borax a cross-linking agent?
In this research, borax was introduced as a cross-linker in order to enhance stability and properties of the hydrogels prepared from water hyacinth fibers (WHFs), and effect of the borax contents on hydrogel properties was investigated.
How does borax Affect Polymers?
Borax in water forms an ion called the borate ion. When the borax solution is added to the glue solution, the borate ions help link the long polymer molecules to each other so they cannot move and flow as easily.
What is produced when polyvinyl acetate is linked by sodium borate?
Observations and results This is what makes glue viscous, or thick and sticky. When borax (sodium tetraborate) is added to polyvinyl acetate and cross-links the latter’s molecules to each other, the glue solution becomes more viscous.
What is cross-linking in slime?
The borate ion can make weak bonds with the OH groups in the polymer chains so it can link the chains together as shown below. This is called cross-linking. This cross-linking changes the properties of the polymer from a viscous liquid to a far more viscous slime.
Why adding acid to PVA borax slime breaks the cross-linking?
Adding acid to the slime breaks the crosslinking producing a liquid with lower viscosity. Adding alkali reverses the process and the slime should be regenerated.
Why is borax called a cross linker?
Borax forms the borate ion when in solution. This ion has the structure: The borate ion can make weak bonds with the OH groups in the polymer chains so it can link the chains together as shown below. This is called cross-linking.
Why can poly vinyl alcohol gels flow?
In the aqueous borax solutions of PVA, the gelation process occurs through intermolecular hydrogen bonds between hydroxyl groups on PVA chains because of the intervention of a borate anion. The crosslinking points are therefore exchangeable, which results in the gel flowing extremely slowly.
What is cross-linking How does cross-linking happen?
Cross-links can be formed by chemical reactions that are initiated by heat, pressure, change in pH, or irradiation. For example, mixing of an unpolymerized or partially polymerized resin with specific chemicals called crosslinking reagents results in a chemical reaction that forms cross-links.
Does polyvinyl alcohol have alcohol in it?
Furthermore, given its varied application and usability, PVA is in demand in various industrial markets such as textile, coatings, paper, ceramics, and wood. Since polyvinyl alcohol consists of ethanol and is water soluble, while being resistant to greases and oils, it is a unique polymer, with few capable substitutes.
What is borax powder?
Borax is a powdery white substance, also known as sodium borate, sodium tetraborate, or disodium tetraborate. It’s widely used as a household cleaner and a booster for laundry detergent. Both borax and boric acid in loose powder form can be harmful if swallowed, particularly for children.
Does the glue borax slime react the same as the PVA borax slime?
Now if you reach in and grab one chain, you’ll lift out the entire pile. Adding a Borax solution to the PVA does pretty much the same thing (only it’s a chemical, not a magnetic, connection). Borax loves to connect with water.
Is it possible to cross-link PVA with boric acid?
In this study, different hydrolyzed PVA is cross-linked in water solution with boric acid as a cross-linking agent to observe the effects on physical, mechanical and thermal properties of PVA solutions. 2. Experimental
What is polyvinyl alcohol with borax?
Slime – Polyvinyl Alcohol with Borax Description: This demonstration is typically performed as a hands-on activity for younger audiences but can also be used to discuss polymerization. Two clear colorless liquids are mixed and immediately form a gel with interesting physical properties.
What is cross linker in PVA?
PVA has been cross-linked with cross-linking agents, such as weak Lewis acid aluminium chloride, zirconium chloride, titanium chloride, etc. The cross-linking helps to improve the mechanical properties and water sta- bility of PVA based products. Boric acid is a commonly used cross-linker for PVA for various applications.
What is the ratio of polyvinyl alcohol to sodium borate?
The polyvinyl alcohol and sodium borate are mixed together in approximately a 10 to 1 ratio. 100 ml of the 4% poly (vinyl alcohol) is added to a Styrofoam cup . Food coloring can be added to the PVA in the cups to make different colors.
