水介质中丁腈橡胶溶胀机理及其对磨粒磨损行为影响

研究首先对不同丙烯腈质量分数的丁腈橡胶（18%、26%和41%，即N18、N26和N41）进行浸泡试验分析基于溶胀时间的静态溶胀行为. 然后进一步对溶胀前后的丁腈橡胶样品进行圆型及角型磨粒单向滑动磨粒磨损试验. 为了揭示丁腈橡胶的溶胀机理及溶胀对不同粒型作用下磨粒磨损行为的影响，对试样进行质量、硬度、交联链比重（NMR）和表面形貌（SEM）测试. 结果表明：丁腈橡胶溶胀度随时间的增加而增加，并于240 h后趋于平衡，溶胀影响下老化的主要原因为交联链破坏和物质溶解.丁腈橡胶硬度随溶胀时间的增加而降低. 溶胀后摩擦系数和磨损量增加，同粒径下磨粒磨损程度角型大于圆型，角型磨损受溶胀影响程度更大，其最大溶胀后磨损增量为圆型磨粒的1.56倍. 圆型和角型磨粒分别以滚动和滑动的方式进入摩擦副，形成压入坑和嵌入坑两种不同的表面形貌，溶胀后橡胶组织疏松软化导致表面凹坑加深. 丁腈橡胶溶胀及其对磨粒磨损的影响程度随丙烯腈含量的增加而减小.This study first conducted immersion tests on nitrile rubber (NBR) samples with different acrylonitrile mass fractions (18%, 26%, and 41%, denoted as N18, N26, and N41 respectively) to analyze their static swelling behavior based on swelling time. Subsequently, unidirectional sliding abrasive wear tests using round and angular abrasive particles were further performed on the NBR samples before and after swelling. To reveal the swelling mechanism of NBR and the effect of swelling on its abrasive wear behavior under different particle morphologies, tests including mass, hardness, crosslink chain density (characterized via NMR), and surface morphology (observed via SEM) were carried out on the specimens. The results show that: the swelling ratio of NBR increases with prolonged swelling time and tends to reach equilibrium after 240 h; the main aging effects under swelling are crosslink chain scission and substance dissolution. The hardness of NBR decreases with increasing swelling time. After swelling, both the friction coefficient and wear volume increase. Under the same particle size, the abrasive wear degree is greater for angular particles than round ones, and the wear of angular particles is more significantly affected by swelling, with its maximum post-swelling wear increment reaching 1.56 times that of round abrasive particles. Round and angular abrasive particles enter the friction pair via rolling and sliding modes respectively, forming two distinct surface morphologies: indentation pits and embedded pits. The loosened and softened microstructure of rubber after swelling leads to deeper surface pits. The degree of NBR swelling and its effect on abrasive wear decrease with increasing acrylonitrile content.

搜集汇总

背景与挑战

背景概述

该数据集研究了水介质中丁腈橡胶（N18、N26和N41）的溶胀机理及其对磨粒磨损行为的影响，通过浸泡试验和磨粒磨损试验（圆型及角型磨粒）进行分析。结果表明，溶胀度随时间增加至240小时后平衡，导致硬度降低、摩擦系数和磨损量增加，角型磨粒磨损更严重，且影响程度随丙烯腈含量增加而减小。