INFLUENCE OF MOLECULAR-WEIGHT DISTRIBUTION ON THE STRUCTURE AND PROPERTIES OF MELT-SPUN POLYPROPYLENE FILAMENTS
INFLUENCE OF MOLECULAR-WEIGHT DISTRIBUTION ON THE STRUCTURE AND PROPERTIES OF MELT-SPUN POLYPROPYLENE FILAMENTS
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DOI：
10.1002/app.1995.070561307
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发表时间：
1995-06-27
影响因子：
3
通讯作者：
RICHESON, GC
中科院分区：
文献类型：
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作者：
MISRA, S;LU, FM;RICHESON, GC
研究了分子量分布对熔纺等规聚丙烯长丝的可纺性、结构和性能的作用，目的是明确区分分布宽度与平均分子量和树脂熔体流动速率（MFR）的作用。为此目的选择了九种树脂，其MFR范围为16至78，多分散性范围为2.6至5.4。据观察，纺丝的可纺性，结构和性能的长丝的分布的宽度的所有强功能。可纺性随幅值的增加而降低。在给定的纺丝条件和多分散性下，重均分子量的增加（MFR的降低）产生结晶度、双折射、拉伸强度和拉伸模量的增加。但在给定的纺丝条件和树脂MFR下，加宽分子量分布（增加多分散性）产生结晶度、拉伸模量和断裂伸长率的增加，而双折射和拉伸强度降低。多分散性对结构和性能的主要影响归因于其对树脂的拉伸粘度和分布中高分子量尾部影响纺丝线中发生的应力诱导结晶的能力的影响。(C)John Wiley & Sons，Inc.
The role of molecular weight distribution on the spinnability, structure, and properties of melt-spun isotactic polypropylene filaments was studied with the aim of clearly distinguishing the effect of the breadth of the distribution from the effect of the average molecular weight and resin melt flow rate (MFR). Nine resins were chosen for this purpose, ranging in MFR from 16 to 78 and in polydispersity from 2.6 to 5.4. It was observed that the spinnability, structure, and properties of the spun filaments were all strong functions of the breadth of the distribution. Spinnability decreased with increasing breadth. At given spinning conditions and polydispersity, an increase in the weight-average molecular weight (decrease in MFR) produces an increase in crystallinity, birefringence, tensile strength, and tensile modulus. But at given spinning conditions and resin MFR, broadening the molecular weight distribution (increasing the polydispersity) produces an increase in crystallinity, tensile modulus, and elongation-to-break while birefringence and tensile strength decrease. The major influence of the polydispersity on the structure and properties developed was attributed to its effect on both the elongational viscosity of the resin and the ability of high molecular weight tails in the distribution to influence the stress-induced crystallization that occurs in the spinline. (C) 1995 John Wiley & Sons, Inc.