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柔性链高分子特性粘数[η]的温度、溶剂、分子量依赖性,目前以 Flory-Fox 理论与实验事实最相符合,即[η]=φ(■~(3/2))/Mx~3=K_θM~(1/2)x~3,式中■是在没有链段间和链段与溶剂分子间的相互作用时高分子链的均方末端距,M 是分子量,x 是溶胀因子,依赖于温度、溶剂和分子量。当链段间无远程相互作用时 x=1,φ是一个普适常数,K_θ对给定高分子是一个常数。但是 Flory-Fox 理论对聚酰胺溶液的粘度行为是否也适用,有两点理由可以置疑:(1)聚酰胺分子链的聚合度比较小,在10~2的数量级,(2)由于酰胺键的氢键作用,分子链的柔性可能比较差,因此与一般的无规线团高分子溶液的粘度行为很可能有所不同。由于聚酰胺溶剂的选择比较困难,溶液性质的研究做得很少。Liquori,Mele 曾研究过聚酰
The intrinsic viscosity [η] of the flexible chain macromolecule is dependent on the temperature, the solvent and the molecular weight. At present, Flory-Fox theory agrees well with the experimental fact that [η] = φ (■ ~ (3/2)) / Mx ~ 3 = K_θM ~ (1/2) x ~ 3, where ■ is the mean square end distance of the polymer chain in the absence of interaction between segments and segments and solvent molecules, M is the molecular weight, and x is the swelling factor , Depending on temperature, solvent and molecular weight. When there is no long-range interaction between segments x = 1, φ is a universal constant and K_θ is a constant for a given polymer. However, Flory-Fox theory is also applicable to the viscosity behavior of polyamide solution. There are two reasons for this: (1) the degree of polymerization of polyamide chains is relatively small, on the order of 10 to 2, (2) Hydrogen bond, the flexibility of the molecular chain may be poor, so with the general random coil polymer viscosity behavior is likely to be different. Due to the difficulty of selecting polyamide solvents, the nature of the solution has been poorly studied. Liquori, Mele has studied polyamides