Pykrete vs. Ice Comparison

Water and Saw Dust (wood pulp) are the essential
ingredients in Pykrete. This image shows about a 1:1
ratio while Pykrete is about 6:1 water to wood pulp

Ice and Pykrete are very similar in their general make-up since the pykrete mixture is roughly 14% sawdust (wood pulp) and 86% ice. So when comparing the slight difference in the two materials physical structure, pykrete only varies by a sixth of the total weight of the pure ice. In pure ice, hydrogen and oxygen atoms form six-sided crystalline structures causing the water to expand as it nears its freezing point. The molecules’ motion begins to slow with the decrease in temperature, and because of the properties of hydrogen-bonding the hydrogen bonds extend out the molecule to the greatest distance from one another, so when the molecules begin to do this the side-sided structures expand into a larger structure that continues to to get larger until it reaches complete solidity.

Visual of the forming of the six-sided crystalline structures

This property is easily seen in snowflakes. When a flake is observed under magnification, it is evident that all the individual snowflakes present with six sides. This is due to the all intermolecular and intramolecular forces acting on the H2O molecule in addition to hydrogen-bonding.

 But the space between the structures is what allows pykrete to flourish. The cellulose fibers of the sawdust is what further improves the water's durability and strength. In comparing the strength of the two, ice has a tensile strength of 1.103MPa and pykrete has a tensile strength of 4.826MPa. Just to shed some light on how high the tensile strength of pykrete, concrete has a tensile strength of 1.724MPa. Unfortunately Concrete has a crushing strength some 2.5 times that of pykrete, and also pykrete is extremely hard to make compared to concrete and just like pure ice it also expands as it freezes so it’s not easy trying to make it a specific shape. But the density of pykrete parallels that of ice, which is what allows the pykrete to float when placed in water just like the ice.

Thermal conductivity is the rate at which heat can move through a substance, the speed that ice melts is what we use to measure its thermal conductivity.. Thermal conductivity is the rate at which heat can move through a substance, the speed that ice melts is what we use to measure its thermal conductivity. The thermal conductivity, in regards to ice, is the speed at which it melts. The physical process of ice melting happens when the chemical bonds between the molecules in the crystalline structure of ice are broken due to the heat activity. When the wood fibers are added the particles lower the overall thermal conductivity, which slows the melting.

Shows the rate at which ice melts in comparison to pykrete