填料微观形态对聚双环戊二烯树脂的增强机理研究

Polydicyclopentadiene (PDCPD) is a novel cross-linked polymer, and research on the mechanical enhancement of PDCPD composites is increasingly concerned due to PDCPD’s excellent properties, low cost and easy forming process. However, as for mechanical enhancement effect of PDCPD composite, existed research is confined to the influence of interface compatibility between the filler and the resin matrix, while ignoring the impact of the filler’s morphology in PDCPD composite. In this project, three typical fillers were selected and different groups were quantitatively introduced to fillers by surface functionalization, the effect of filler/DCPD ring opening metathesis polymerization (ROMP) reaction parameters on filler morphology was evaluated, and the impact of filler’s morphology on the final mechanical properties of PDCPD composite was further studied. By comparative study on the relationship among filler/DCPD ROMP reaction parameters, filler’s morphology and the mechanical properties of the composite, clarifying the impact mechanism of the reaction parameters on the filler’s morphology, revealing the reinforcing mechanism of filler’s morphology on the mechanical properties of the composites, finding a new way to control the mechanical property by the structure. Both from the point views of basic research and industrial application, this research are of great scientific and practical significance.

聚双环戊二烯（PDCPD）是一种新型热固性树脂，由于其高性能、低成本、易成型加工，其复合材料的力学增强研究日益受到重视。然而，现有研究在考察PDCPD复合材料的力学增强效果时，仅局限于填料和树脂基体界面相容性的影响，而忽略了PDCPD复合材料中的填料微观形态的影响。本项目中，选择三种典型填料，通过填料表面功能化引入定量的不同官能团，评价填料/DCPD的开环易位聚合（ROMP）反应参数对PDCPD复合材料中填料微观形态的影响，进而研究填料微观形态对PDCPD复合材料力学性能的影响。拟通过比较研究填料/DCPD的ROMP反应参数、填料微观形态以及复合材料力学性能之间的关系，阐明ROMP的反应参数对填料微观形态的影响机理，揭示填料微观形态对复合材料力学性能的增强机理，为PDCPD复合材料的结构与性能控制找到规律性认识。此研究无论是从基础研究还是从工业应用的角度，都具有重要的科学意义和实际意义。

本项目采用不同维度的定量官能团功能化填料，探讨填料/DCPD体系的固化反应对填料微观形态的影响，进而研究PDCPD复合材料的增强增韧及其机理。此外，本项目将研究延伸至如下两个领域：不同维度的填料对取代聚乙烯的附生结晶行为的影响；不同维度填料对超临界CO2发泡聚乙烯的形貌调控的影响。取得了一系列有特色的创新性成果。. 不同官能团功能化的SiO2纳米填料对聚双环戊二烯树脂的增强增韧效果及其机理不同。较纯PDCPD材料，PDCPD/0.2wt% V-SiO2（乙烯基功能化SiO2）复合材料的屈服强度有所下降，而其断裂伸长率从9.0%显著增加至143.4%，使韧性从2.58提高到40.94 MPa，提高了约14倍。PDCPD/V-SiO2对韧性的显著提高归因于V-SiO2促进了拉伸过程中微孔和微裂纹的形成，此过程中吸收了大量能量。较纯PDCPD材料，PDCPD/0.3wt% P-SiO2（苯基功能化SiO2）复合材料的断裂伸长率有所下降，而屈服强度和冲击强度均明显上升，分别增加了63%和220%。PDCPD/P-SiO2对冲击强度的显著增强可能归因于P-SiO2与基体材料之间很好的结合牢度，使得冲击测试中载荷很好地转移给刚性P-SiO2。. 采用溶液共混方法制备了 PE21Br(取代基间隔为21个碳原子的精确取代聚乙烯)/单壁碳纳米管和PE21Br/还原石墨烯复合材料。PE21Br在单壁碳纳米管表面形成串晶，PE21Br在石墨烯基底表面平行方向生成棒状晶体。单壁碳纳米管和还原石墨烯促进了晶格结构的有序，诱导 PE21Br 结晶的晶格结构由三斜晶转变为正交晶。PE21Br/单壁碳纳米管和PE21Br/还原石墨烯复合材料的熔融温度比本体的分别高出约 20°C和97°C.. 线性低密度聚乙烯/碳纳米管复合发泡材料中，碳纳米管的加入不仅促进了泡孔的异相成核，也防止了开孔过程中泡孔塌陷，防塌陷是实现泡孔尺寸小、泡孔密度高的开放泡孔结构的关键。