Polymers are typically a mixture of chains with different lengths, and therefore different molecular weights. The average molecular weight is a way to characterize the overall size of the polymer molecules in a sample. There are different ways to calculate average molecular weight, including number-average molecular weight (Mn) and weight-average molecular weight (Mw). These values influence the properties of the polymer, such as viscosity, melting point, and mechanical strength.

聚合物通常是具有不同长度、因此具有不同分子量的链的混合物。平均分子量是一种表征样品中聚合物分子整体尺寸的方法。有多种方法可以计算平均分子量，包括数均分子量 (Mn) 和重均分子量 (Mw)。这些值会影响聚合物的性能，例如粘度、熔点和机械强度。