Rheological Study of Polymers Used as Viscosity Index Improvers for Automotive Lubricant Oils
Rheological Study of Polymers Used as Viscosity Index Improvers for Automotive Lubricant Oils
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汽车润滑油粘度指数改进剂聚合物的流变学研究
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
Maria Elisa Scarpelli Ribeiro e Silva
中科院分区：
文献类型：
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作者：
A. Almeida;Ana Paula Lelis Rodrigues de Oliveira;Cynthia D’Avila Carvalho Erbetta;R. Sousa;R. Freitas;Maria Elisa Scarpelli Ribeiro e Silva
在这
工作，汽车润滑油的流变学研究，中性光
石蜡（NLP）和中性介质石蜡（NMP），添加两种
基于氢化聚乙烯的商业粘度指数改进剂-VII
（异戊二烯-共-苯乙烯）的聚合反应。研究
包括测定混合物的运动粘度，
粘度指数的计算及其在经受
各种流变学实验，包括应力扫描，稳态流动，
蠕变和恢复，以及温度斜坡振荡试验。所获得的
结果表明添加剂作为粘度指数改进剂的功效，
纯油的粘度指数在相对温度下显著增加
低浓度。确定储存量（G '）和损失量（G”）
油/VII添加剂混合物的模量显示出
粘性效应大于弹性效应。除了在低剪切应力下，
随着流动曲线的调整，混合物表现出假塑性行为
拟合Ostwald-de-Waele模型（幂律），具有负流动行为
钻石时标
In this
work, a rheological study of automotive lubricant oils, neutral light
paraffinic (NLP) and neutral medium paraffinic (NMP), additivated with two
commercial viscosity index improvers-VIIs, based on hydrogenated poly
(isoprene-co-styrene), at different concentrations, was carried out. The study
included the determination of the kinematic viscosity of the mixtures, the
calculation of the viscosity indexes and their behavior when subjected to
various rheometric experiments, including stress sweep, steady state flow,
creep and recovery, and temperature ramp oscillatory tests. The obtained
results showed the efficacy of the additives as viscosity index improvers, enabling
a significant increase in the viscosity index of the pure oils at relatively
low concentrations. The determination of the storage (G’) and of the loss (G”)
moduli for the mixtures oil/VII additives showed a large predominance of the
viscous effect over the elastic one. Except when under low shear stress, the
mixtures showed a pseudoplastic behavior, with the flow curves being adjusted
to fit the Ostwald-de-Waele model (Power Law), with negative flow behavior
indexes.