Highly Improved Creep Resistance in Polypropylene Through Thermally Reduced Graphene Oxide and Its Creep Lifetime Prediction
Highly Improved Creep Resistance in Polypropylene Through Thermally Reduced Graphene Oxide and Its Creep Lifetime Prediction
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DOI：
10.1007/s10118-023-3028-x
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发表时间：
2023-07
影响因子：
4.3
通讯作者：
Can-Can Zhang-Can;Junfen Yang;Yajiang Huang;Guang-xian Li
中科院分区：
文献类型：
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作者：
Can-Can Zhang-Can;Junfen Yang;Yajiang Huang;Guang-xian Li
聚丙烯（PP）由于其主链上存在甲基而表现出次优的抗蠕变性，导致不规则的链段分布、减少的链间相互作用和结晶度。这种结构特征导致PP在应力下的链滑移，显著限制了其使用寿命。在这项研究中，热还原氧化石墨烯（TrGO）纳米片被纳入到PP基体，产生具有优异的抗蠕变性能的纳米复合材料。结果表明，在25 MPa的应力下，2.0 wt%的TrGO含量可以使PP的蠕变失效寿命比纯PP提高21.5倍。采用流变学、透射电镜（TEM）和扫描电镜（SEM）表征技术分析了TrGO对PP蠕变行为的影响机理。据观察，当TrGO含量超过1.0wt%时，在PP基体内形成有效的颗粒网络结构。这种均匀分散的TrGO形成的颗粒网络结构限制了PP分子链的迁移和重排，从而能够延长应力抵抗力而不会发生结构破坏。采用时间-应变叠加法，以临界破坏应变为判据，建立了PP及其复合材料的广义蠕变柔量曲线，预测了材料的蠕变破坏寿命，实验值与预测值吻合较好。该研究提出了一种新的策略，旨在开发具有增强的长期稳定性和耐用性的聚丙烯材料和产品，从而延长使用寿命，降低故障风险，并扩大其在各个应用领域的潜力。
Polypropylene (PP) exhibits suboptimal creep resistance due to the presence of methyl groups on its main chain, leading to irregular chain segment distribution, diminished inter-chain interaction, and crystallinity. This structural feature causes chain slippage in PP under stress, significantly constraining its service lifetime. In this study, thermally reduced graphene oxide (TrGO) nanosheets were incorporated into the PP matrix, yielding a nanocomposite with exceptional creep resistance performance. Results demonstrated that at a stress of 25 MPa, a 2.0 wt% TrGO content could enhance the creep failure lifetime of PP by 21.5 times compared to neat PP. Rheology, transmission electron microscopy (TEM), and scanning electron microscopy (SEM) characterization techniques were employed to analyze the mechanism of TrGO’s influence on PP’s creep behavior. It was observed that when TrGO content exceeded 1.0 wt%, an effective particle network structure formed within the PP matrix. This homogeneously dispersed TrGO-formed particle network structure restricted the migration and rearrangement of PP molecular chains, enabling prolonged stress resistance without structural failure. By combining the time-strain superposition method with the critical failure strain as a criterion, generalized creep compliance curves for PP and its composites were established, facilitating the prediction of material creep failure lifetimes, with a strong agreement between experimental and predicted lifetime values. This research proposes a novel strategy aimed at developing polypropylene materials and products with enhanced long-term stability and durability, thus extending service life, reducing failure risk, and broadening their potential across various application domains.