That is, they consist of two or more simple linear molecules bonded together. In addition, there are less organized forms of association between polymers. The most common polymer conformation is the random coil conformation, in which each bit of the molecule is oriented randomly with respect to the others. A rarer conformation is the aptly named linear conformation, in which all the bits are lined up in a straight line. In order to aggregate, there must be an attractive interaction.
Polymers are clearly too small to measure directly.
Not even close. And this is a big polymer. Consider the size, then. It is a general principle that you can see a thing only by bouncing something off of it that has a wavelength much smaller than the thing you want to see. It seems clear that due to the tiny scales involved, we will generally not be able to view polymers directly, but rather we will have to do so indirectly.