Using 80% dipropylene glycol and 20% 1,4-butanediol as molecular regulator could also narrow the molecular weight distribution and reduce the amount of smaller molecules in product.

• 研究还发现分子量调节剂对产品分子量分布有较大影响，采用混合型调节剂也能够使分子量分布变窄并降低小分子物质含量。