Rodríguez-Uicab Omar, Guay Ian, Abot Jandro L, Avilés Francis
Department of Mechanical Engineering, The Catholic University of America, Washington, DC 20064, USA.
Centro de Investigación Científica de Yucatán A.C., Unidad de Materiales, Calle 43 No. 130 × 32 y 34, Col. Chuburná de Hidalgo, C.P. 97205 Mérida, Yucatán, Mexico.
Polymers (Basel). 2021 Mar 4;13(5):783. doi: 10.3390/polym13050783.
The effect of polymerization kinetics and resin viscosity on the electrical response of a single carbon nanotube yarn (CNTY) embedded in a vinyl ester resin (VER) during polymerization was investigated. To analyze the effect of the polymerization kinetics, the concentration of initiator (methyl ethyl ketone peroxide) was varied at three levels, 0.6, 0.9, and 1.2 wt.%. Styrene monomer was added to VER, to reduce the polymer viscosity and to determine its effect on the electrical response of the CNTY upon resin wetting and infiltration. Upon wetting and wicking of the CNTY by VER, a transient decrease in the CNTY electrical resistance (ca. -8%) was observed for all initiator concentrations. For longer times, this initial decrease in electrical resistance may become a monotonic decrease (up to ca. -17%) or change its trend, depending on the initiator concentration. A higher concentration of initiator showed faster and more negative electrical resistance changes, which correlate with faster gel times and higher build-up of residual stresses. An increase in styrene monomer concentration (reduced viscosity) resulted in an upward shift of the electrical resistance to less negative values. Several mechanisms, including wetting, wicking, infiltration, electronic transfer, and shrinkage, are attributed to the complex electrical response of the CNTY upon resin wetting and infiltration.
研究了聚合动力学和树脂粘度对乙烯基酯树脂（VER）聚合过程中嵌入其中的单根碳纳米管纱（CNTY）电响应的影响。为了分析聚合动力学的影响，引发剂（过氧化甲乙酮）的浓度在0.6、0.9和1.2 wt.%三个水平上变化。向VER中添加苯乙烯单体，以降低聚合物粘度，并确定其对树脂润湿和渗透时CNTY电响应的影响。当VER对CNTY进行润湿和芯吸时，在所有引发剂浓度下均观察到CNTY电阻出现短暂下降（约-8%）。对于较长时间，这种电阻的初始下降可能会变成单调下降（高达约-17%）或改变其趋势，这取决于引发剂浓度。较高的引发剂浓度显示出更快且更负的电阻变化，这与更快的凝胶时间和更高的残余应力积累相关。苯乙烯单体浓度的增加（粘度降低）导致电阻向上移动至较不负的值。包括润湿、芯吸、渗透、电子转移和收缩在内的几种机制被认为是导致树脂润湿和渗透时CNTY复杂电响应的原因。
