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Polymer degradation is a change in the properties—tensile strength, color, shape, or molecular weight—of a polymer or polymer-based product under the influence of one or more environmental factors, such as heat, light, and the presence of certain chemicals, oxygen, and enzymes.
The simple reactive molecule from which the repeating structural units of a polymer are derived is called a monomer. A polymer can be described in many ways: its degree of polymerisation , molar mass distribution , tacticity , copolymer distribution, the degree of branching , by its end-groups , crosslinks , crystallinity and thermal properties ...
A graft polymer molecule is a branched polymer molecule in which one or more of the side chains are different, structurally or configurationally, from the main chain. A star-shaped polymer molecule is a branched polymer molecule in which a single branch point gives rise to multiple linear chains or arms.
In polymer chemistry, polymerization (American English), or polymerisation (British English), is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks. [1] [2] [3] There are many forms of polymerization [4] and different systems exist to categorize them.
According to the standard IUPAC definition, the term macromolecule as used in polymer science refers only to a single molecule. For example, a single polymeric molecule is appropriately described as a "macromolecule" or "polymer molecule" rather than a "polymer," which suggests a substance composed of macromolecules. [8]
A repeat unit is sometimes called a mer (or mer unit) in polymer chemistry. "Mer" originates from the Greek word meros, which means "a part". The word polymer derives its meaning from this, which means "many mers". A repeat unit (mer) is not to be confused with the term monomer, which refers to the small molecule from which a polymer is ...
A monomer (/ ˈ m ɒ n ə m ər / MON-ə-mər; mono-, "one" + -mer, "part") is a molecule that can react together with other monomer molecules to form a larger polymer chain or three-dimensional network in a process called polymerization. [1] [2] [3]
Polymer science or macromolecular science is a subfield of materials science concerned with polymers, primarily synthetic polymers such as plastics and elastomers. The field of polymer science includes researchers in multiple disciplines including chemistry , physics , and engineering .