炭纤维/乙烯基酯树脂复合材料拉挤工艺及力学性能的研究
作者：李鹏
院校:北京化工大学
关键字:炭纤维;乙烯基酯树脂;复合材料;拉挤;表面处理
学位：硕士
专业:应用化学
摘要:
本文研究了炭纤维／乙烯基酯树脂拉挤复合材料配方、成型工艺及所得的拉挤复合材料的力学性能。通过对乙烯基酯树脂固化特征分析，确定了炭纤维／乙烯基酯树脂拉挤成型工艺的引发体系及各工艺参数(三段温度、拉挤速度等)，研究了引发体系及不同工艺参数对成型工艺的影响。在炭纤维／乙烯基酯树脂复合材料拉挤工艺中引入了炭纤维在线表面处理新工艺，制备出了性能优良的炭纤维树脂基拉挤复合材料。 首先分析了乙烯基酯树脂的固化特性，采用具有不同引发效率的有机过氧化物引发剂，通过示差扫描量热(DSC)及红外吸收光谱(IR)分析了不同引发剂联用对树脂凝胶点、固化放热峰温度以及固化度的影响，结果表明合适的引发剂联用能够提高基体树脂的固化良并有利于拉挤工艺。 其次研究了炭纤维／乙烯基酯树脂复合材料拉挤成型的工艺及优化条件，分析了炭纤维含量及内脱模剂的使用对拉挤工艺和复合材料力学性能的影响，研究了模具温度和拉挤速度的协调关系，分析了拉挤工艺过程中常见的缺陷及缺陷造成的原因，得到了适应炭纤维复合材 北京化工大学硕士学位论文 料抽油杆产品连续稳定拉挤的工艺条件。 最后研究了复合材料的界面改善对其力学性能的影响，提出了在 碳纤维/乙烯基酷树脂基复合材料拉挤成型过程中引入炭纤维在线表面 处理的新工艺，既可去除商用炭纤维表面与乙烯基酷树脂不相容上胶 层，同时在保持炭纤维强度的情况下，改善了炭纤维表面粗糙度和含 氧官能团。分析了炭纤维与树脂界面性能的改善对复合材料层间剪切 强度的影响，结果表明所得的拉挤复合材料的层间剪切强度可由未处 理时的45MPa提高到72 MPa;通过动态热机械分析(DM[A)初步研 究了界面改善对材料的内耗因子、弹性模量、储能模量的影响，结果 表明复合材料界面粘接程度的改善，降低了材料的损耗因子和损耗模 量，可以提高复合材料的耐疲劳性能，这种界面性能的改善尤其对于用 于长期交变疲劳载荷下的碳纤维复合材料抽油杆是有益的。
Abstract:
The matrix formulations, pultrusion processes and mechanical properties of the pultruded carbon fiber/vinyl ester resin composites were investigated. A new method was employed to on-line treat the carbon fibers during pultrusion processing. In order to find a resin matrix favorable for the pultrusion, the combinations of two kinds of organic-peroxide initiators were used, and the curing characteristics of the resulting resin matrix were studied using Differential Scanning Calorimeter (DSC) and Infra-red spectrometer (1R). The pultrusion processes (temperature and speed) and the effect of fiber fractional and release agent on the mechanical properties of the composites were analyzed individually. In addition, the effects of interface between carbon fibers (CF) and resin matrix on the mechanical properties of the composites were researched by using Dynamic Mechanical Thermal Analysis (DMTA) and Scanning Electron Microscopy (SEM). Resulted showed that a suitable combination of initiators enhanced the curing degree of resin matrix and was favorable for the pultrusion. A continuous and stable pultrusion process for carbon fiber/vinyl ester resin composites was obtained by adjusting pultrusion temperature, pultrusion speed and matrix formulation. The Surface treatment on carbon fibers by means of air-oxidization removed the sizing incompatible with vinyl ester resin, improved the carbon fiber surface roughness, increasing the interlaminar shear strength (ILSS) from 45 MPa for un-treatment to 70 MPa for treatment. DMTA results indicated that the improvement of the interfacial adhesion between carbon fibers and resin matrix reduced tg 8 and loss modulus, which is useful in improving the composites fatigue-resistance.