| The existing thermoplastic polymers use 1D chains. The thermosetting polymers are initially synthesized as 1D chains, but after they are made into their intended form, the curing reaction cross-links all the 1D chains into a 3D network. Because of its 3D structure, a cured thermosetting polymer can no longer be dissolved or melted. At high temperatures it will decompose or burn, instead of melting. However, the thermosetting polymers, unlike covalent crystals like diamond, boron or silicon, have a 3D structure with big holes in it, so they are permeable to gases and other substances with small molecules. The 2D polymer discussed in the parent article has a 2D structure similar to graphite sheets, i.e. a dense 2D lattice, without holes or pores. This dense structure allows applications that cannot be done with traditional polymer coatings. This coating should be inpermeable like a glass, without being fragile. The fact that it is light, as mentioned in the title, is pretty much irrelevant, because this is a material that is suitable only for coatings on objects made of other materials, not for the bulk material of an object. |