Branching (polymer chemistry) Branching (polymer chemistry) In polymer chemistry, branching occurs by the replacement of a substituent, e.g., a hydrogen atom, on a monomer subunit, by another covalently bonded chain of that polymer; or, in the case of a graft copolymer, by a chain of another type. Branched polymers have more compact and symmetrical molecular conformations, and exhibit intra-heterogeneous dynamical behavior with respect to the unbranched polymers. In crosslinking rubber by vulcanization, short sulfur branches link polyisoprene chains (or a synthetic variant) into a multiply branched thermosetting elastomer. Rubber can also be so completely vulcanized that it becomes a rigid solid, so hard
Polymer blend more than one kind of polymer. A new polymers modification process, based on a simple mechanical mixture of two polymers first appeared when Thomas Hancock got one mixture of natural rubber with gutta-percha. This process generated a new polymer class called "polymer blends". Polymer blends can be broadly divided into three categories: The use of the term polymer alloy for a polymer blend is discouraged, as the former term includes multiphase copolymers but excludes incompatible polymer blends. Examples of miscible polymer blends: Polymer blends can be used as thermoplastic elastomer Polymer blend A polymer blend, or polymer mixture, is a