【摘要】：超高分子量聚乙烯纖維由于超高的分子量、高纏結度的分子鏈,以及經過高倍率拉伸產生具有高取向度、高結晶度的伸直鏈結構,具有極佳的力學性能、化學穩(wěn)定性、耐磨、低表面性能,是作為高性能濾布的理想材料,這是其它纖維無法比擬的。本課題選用中等分子量MP、小分子物質LP為改性劑,采用熔體紡絲法制備UHMWPE纖維,將制備的纖維織造成2/2斜紋組織單絲濾布。本課題研究了改性劑對UHMWPE原料的改性機理;探究超倍率拉伸的工藝參數(拉伸溫度、拉伸倍率、停留時間)對UHMWPE纖維性能的影響,為下一步工廠大規(guī)模生產制備UHMWPE濾用纖維提供經驗參考;探究熱定型工藝參數(定型溫度、定型時間、定型張力)對UHMWPE單絲濾布的機械性能、透氣性能、尺寸穩(wěn)定性、鼓泡孔徑等性能的影響,建立濾布性能與熱定型工藝各因子之間的經驗關系;篩選出最佳熱定型工藝條件。通過分析,改性劑MP、LP協(xié)同改變UHMWPE的流動性和可紡性,LP分子鏈使UHMWPE晶區(qū)片晶解纏,而MP則是降低非晶區(qū)的大分子鏈間的纏結點密度。但添加量達到20份時,會造成纖維的性能下降。在適宜的油浴溫度、拉伸倍率、停留時間等條件下,纖維大分子鏈會沿應力方向的取向,其力學性能會得到極大提高。但長時間在過高的溫度會使大分子鏈熱解、產生無效滑移,過高的拉伸倍率使纖維結構的缺陷度增大,一級拉伸最佳溫度約為90°℃、最佳倍率約為25倍。在合適的定型溫度、時間、經向張力條件下,UHMWPE濾布纖維內的結晶度、結晶完整性會得到提高,濾布的結構變得更加的規(guī)整、致密、穩(wěn)定,孔徑也更加均勻。而長時間高溫下的定型會使濾布纖維分子鏈熱解、重結晶,加速了濾布的老化,致使濾布的缺陷增大、性能下降。UHMWPE單絲濾布的最佳熱定型溫度約為100℃,定型時間約為90s,經向張力約為100KN。熔體紡絲法制備出的UHMWPE纖維,完全能滿足制作單絲濾布的要求。
[Abstract]:UHMWPE fibers have excellent mechanical properties, chemical stability and wear resistance due to their ultra-high molecular weight, high entanglement molecular chain, and elongation chain structure with high orientation and high crystallinity after drawing at high rate. Low surface performance is an ideal material for high performance filter cloth, which can not be compared with other fibers. In this paper, the medium molecular weight MP, small molecular material LP was selected as the modifier, and the UHMWPE fiber was prepared by melt spinning method. The prepared fiber was woven to make 2 / 2 twill tissue monofilament filter cloth. In this paper, the modification mechanism of modifier on UHMWPE raw material was studied. The effects of the process parameters (drawing temperature, drawing ratio, residence time) on the properties of UHMWPE fiber were investigated, which provided the experience reference for large-scale production of UHMWPE filter fiber in the next step. To explore the effects of heat setting process parameters (setting temperature, setting time, setting tension) on the mechanical properties, air permeability, dimensional stability, bubble diameter and other properties of UHMWPE monofilament filter cloth. The empirical relationship between filter cloth performance and various factors of heat setting process is established. The optimum process conditions of heat setting were screened out. Through analysis, the modifier MP,LP co-changed the fluidity and spinnability of UHMWPE. The LP molecular chain unentrapped the UHMWPE wafers, while MP reduced the entanglement point density between the macromolecular chains of amorphous region. However, the addition of 20 phr will result in the degradation of the properties of the fiber. Under the suitable conditions of oil bath temperature, tensile ratio and residence time, the fiber macromolecular chain will be oriented along the stress direction, and its mechanical properties will be greatly improved. However, when the temperature is too high for a long time, the chain will be pyrolyzed, resulting in invalid slippage. The defect degree of the fiber structure will be increased when the drawing ratio is too high. The optimum temperature of the first order drawing is about 90 擄鈩，

本文編號：2416585