Is rubber water resistant

Answer 1

Rubber and most plastics are made primarily from chains of carbon atoms bonded together. Typically two hydrogen atoms are attached to each carbon atom. The bond between the carbon atoms and hydrogen atoms is created by sharing electrons. In the case of carbon and hydrogen, they share electrons evenly, and each carbon atom likes to make 4 bonds, which distributes the hydrogen atoms and the electron around the carbon atoms evenly. The end result is that most rubbers and polymers are not polar. Water is an oxygen atom bonded to two hydrogen atoms. Oxygen likes to bond to two other atoms. The two atoms are not dispersed evenly around the oxygen, hence one side of the oxygen is exposed. Oxygen has more electrons that carbon and is more negatively charged. So an water molecule tends to have a positive end and a negative end (the two hyrdrogens are mostly on one side). Hence water is a very polar molecule. There is a saying that "like disolves like". The positive end(s) of a water molecule are attracted to the negative ends of a water molecule. This is called hydrogen bonding. Hence water molecules are attracted to each other, which is why water is a liquid instead of a vapor. Water molecules are small, and without this hydrogen bonding they wouldn't stick together. The would fly off into the atmosphere. An anology is that each water molecule is like a magnet. If you stick a large number of magnets together they will stick to each other. Since rubber and polymers (plastics) are not usually polar and hence have no significant positive or negative ends or parts, there are no positive or negative charges for water to stick to. Hence they do not typically mix. This description is a broad generalization. Different polymers have different degrees of polarity and varying affinity for water. However rubber is very non-polar so this description is accurate.