Thelargenumberofnaturalandsyntheticpolymershasbeenclassifiedinseveralways.Thesewillbeoutlinedbelow.Theearliestdistinctionbetweentypesofpolymerswasmadelongbeforeanyconcreteknowledgeoftheirmolecularstructure.Itwasapurelyphenomenologicaldistinction,basedonth (共 8061 字) [阅读本文] >>