The internal forces of polymer materials are different from metal bonds and ionic bonds. They are combined by intermolecular forces and hydrogen bonds. Although there are also hydrocarbon, carbon-carbon and other forms of covalent bonds, the forces generated by covalent bonds are negligible in the polymer.
高分子材料内部的作用力与金属键、离子键不同，它是靠分子间作用力以及氢键结合的，虽然内部也有碳氢、碳碳以及其它形式的共价键，但共价键产生的作用力在高分子内是可以忽略不计的。
为了提高高分子的力学性能，人们采用纤维对高分子进行增强，比如我们熟知的碳纤维增强复合材料，这也催生了高分子复合材料的兴起，日常生活中的风电叶片、蜂窝夹芯复合板等等都是高分子复合材料
In order to improve the mechanical properties of the polymer, people use fibers to strengthen the polymer, such as carbon fiber reinforced composite, which is also known as the rise of polymer composite materials. In daily life, wind turbine blades, honeycomb sandwich composite plates and so on are high grade composite materials