论文题目：有机质子酸掺杂聚吡咯导电材料制备及其导电和溶解性能影响 

毕业学生：杨晓格

指导教师：吴唯

中文摘要：

为研究有机质子酸掺杂行为，提高聚吡咯的导电和溶解综合性能，以有机质子酸为掺杂剂，用化学氧化法制得聚吡咯粉末，压片后利用四探针仪器进行电阻率测试，利用正交试验探究了掺杂剂种类、反应温度、掺杂剂用量、氧化剂用量、反应时间对产物电导率的影响。结果表明：掺杂剂用量和氧化剂用量的影响十分显著，样品的电导率随之增加呈现先上升后减小的趋势；反应时间的影响程度一般显著；掺杂剂种类和反应温度在一定范围内的影响不太显著。最佳工艺为选用对甲苯磺酸，反应温度为5℃，掺杂剂、氧化剂用量均为单体的1/3（摩尔比），反应6 h，且在此工艺下制得了电导率约33 S/cm的聚吡咯，并分析了诸因素的影响机理。

采用两相溶液共聚法制得了可溶于乙酸乙酯的PPy-PMMA共聚物，探究并分析了加料配方对产物导电和溶解性能影响。最佳反应条件为在40℃下，n(MMA): n(K₂S₂O₈): n(Py): n(对苯甲磺酸)=2:3:6:4、反应4小时，此条件下制得了70℃溶于乙酸乙酯的溶解度为5.56 g，电导率为1.32 S/cm。

采用溶液混合法制得了可溶于乙酸乙酯的PPy/PMMA复合导电薄膜，研讨了共混条件对薄膜导电、溶解度的影响，表征了薄膜的力学性能。当反应条件为m(PMMA): m(Py)=3:1、n(FeCl₃): n(Py): n(TsOH)=1:3:1、反应4 h时，制得的复合膜70℃溶于乙酸乙酯的溶解度为9.96 g，电导率为4.55 S/cm，拉伸强度达38.6 MPa；并比较了二者工艺合成行为的差异。 

  Abstract:

In order to study Organic proton acid doping behavior and improve both conductivity and solubility of PPy, doped by organic protonic acids, PPy powder was synthesized under chemical oxidation and its conductivity was measured by four-probe method after preforming. Orthogonal experiment was carried out to investigate the influence factors of conductivity, including varieties of dopant, reacting temperature, dosages of dopant & oxidant and reaction time. It was concluded that dosages of dopant and oxidant are both significant. When the dosage is increasing, the conductivity rises first and then descends. In addition, reaction time is kind of remarkable, while varieties of dopant and reaction temperature are not very noticeable. The optimum is to choose p-toluene sulfonic acid, under 5℃, dosages of dopant and oxidant are both 1/3(mole ratio to monomer), lasting for 6h, under which conductivity of PPy prepared reached about 33S/cm. Influencing principles were also analyzed subsequently.

Py and MMA were copolymerized in two-phase solution to prepare soluble PPy-PMMA in ethyl acetate, recipes were researched and influencing factors of conductivity and solubility were analyzed. Concludes turned out to be 40℃, n(MMA): n(K₂S₂O₈): n(Py): n(TsOH)=2:3:6:4, lasting for 4h. In this way, the solubility of specimen prepared is 5.56 g(70℃ in ethyl acetate), conductivity was 1.32 S/cm.

PPy/PMMA composite films were blended in aqua, synthesize conditions were researched and influencing factors of conductivity and solubility were analyzed. Besides, tensile strength of films was represented. The optimum came out to be m(PMMA): m(Py)=3:1, n(FeCl₃): n(Py): n(TsOH)=1:3:1, react for 4h, under which the solubility of composite film was 9.96 g, conductivity was 4.55 S/cm, tensile strength was 38.6 MPa. Diversity of both technologies was illustrated. 

论文题目：Al2O3 / h-BN / Co-POM导热材料的制备及性能研究

毕业学生：刘建华

指导教师：吴唯

中文摘要：

共聚甲醛（Co-POM）具有良好的尺寸稳定性、力学性能、电绝缘性能等特性，因其分子链上无侧链，所以具有规整的分子结构，结晶度高，机械性能十分优异，被称之为金属塑料，产量仅低于聚酰胺（PA）与聚碳酸酯（PC），目前世界上使用量在五大工程塑料中排第三，被大量应用于汽车、水暖灌溉器材、家电等领域。但聚甲醛导热系数较低，难以满足导热方面的要求，限制了其在微电子、LED照明、化工换热器等领域的应用。因此，制得出高导热、优异机械性能的聚甲醛材料具有十分重大的实用价值。

本研究第一部分以共聚甲醛为基体，5μm Al₂O₃为填料，选用四种改性剂对Al₂O₃进行表面修饰，分别为硬脂酸、KH550、KH560和KH570，通过FT-IR、综合热分析仪TG和导热系数仪等测试进行分析，确定出最佳的表面改性剂。探索了改性条件及改性剂用量对Al₂O₃表面改性效果的影响。研究结果表明：通过表面接枝率和红外谱图分析，四种表面改性剂中KH560的改性效果最好，最佳水解时间、改性温度、改性时间和用量分别为60min、70℃、2h和1.5wt%。

为了探究5μm Al₂O₃含量及改性前后对填充材料导热系数、拉伸性能和非等温结晶行为的影响，本研究第二部分以Co-POM为基体树脂，KH560为改性剂，5μm Al₂O₃为导热填料，制得改性前后不同填充量的Al₂O₃/Co-POM材料，通过导热系数、拉伸性能和DSC等分析手段进行测试，探究Al₂O₃含量及改性对材料的影响。研究表明：随Al₂O₃含量增多，Al₂O₃/Co-POM的导热系数增大，未改性Al₂O₃添加量为30wt%时，导热系数为0.46 W/（m·K），拉伸强度为50.63MPa。KH560改性Al₂O₃填充体系中，Al₂O₃添加量为30 wt%时，导热系数为0.63W/（m·K），拉伸强度为55.89 MPa，与未改性Al₂O₃/Co-POM材料相比，两者都有一定的提高。

为了探究填充单一及复配填料尺寸、形态对材料性能的影响，本研究最后一部分以Co-POM为基体，5μm Al₂O₃、15~20μm h-BN和30nm Al₂O₃为填料，制得了不同体系的填充材料，通过导热系数、拉伸性能和DSC等手段进行分析测试，探究填料体系对材料性质的影响。实验结果表明：加入量相近时，片层h-BN填充材料的性能更好，30nm Al₂O₃加入量为10wt%时，导热系数为0.38 W/（m·K），拉伸强度为64.54 MPa；h-BN加入量为8wt%时，导热系数为0.39 W/（m·K），拉伸强度为64.83 MPa。对于复配体系，当填料含量为20wt%时，原料配比为Co-POM /5μm Al₂O₃/30nm Al₂O₃=100/10/10，导热系数为0.43 W/（m·K），拉伸强度为56.23 MPa；原料配比为Co-POM /5μm Al₂O₃/15~20μm h-BN=100/10/10，导热系数为0.51 W/（m·K），拉伸强度为53.41 MPa。

Abstract:

Copolyoxymethylene(Co-POM) material has regular molecular structure with no side-chain, and which is called metallic plastic because of good dimensional stability, mechanical properties, processability and insulation. The output of Co-POM material is only less than PA and PC, and nowadays the usage of Co-POM material ranks third of the five important engineering plastic, Co-POM material is widely applied to many fields, such as electronics and electrical appliances, plumbing and irrigation equipments, automobiles and so on. However, Co-POM material cannot meet the requirement of heat dissipation because of low thermal conductivity, and which limit its application in microelectronics, LED lighting, radiator and other fields. Therefore, it has very practical significance to prepare the Co-POM material with high thermal conductivity and excellent mechanical properties.

In the first part of this research, Co-POM material was choosed as matrix resin, 5μm Al₂O₃ was choosed as thermally conductive fillers, and Al₂O₃ was modified by surface modifiers, which include coupling agent KH550, KH560, KH570 and stearic acid. We confirmed the best modifier by analyses of FT-IR, TG and thermal conductivity measurement. The effects of surface modification were investigated by changing the kind and dosage of modifier, the time and temperature of modification and the hydrolysis time of coupling agent. The results proved that coupling agent KH560 was the best in four surface modifier through calculation of surface grafting degree, infrared spectra and thermal conductivity. The best hydrolysis time, modification time and temperature and dosage of KH560 were 60min, 2h, 70℃ and 1.5wt% respectively.

To investigate the influence of materials’ comprehensive properties with the content and surface modification of 5μm Al₂O₃. Al₂O₃/Co-POM materials were prepared with Co-POM material as matrix resin, KH560 as modifier and 5μm Al₂O₃ as fillers in the second part. The effects of 5μm Al₂O₃ content and filler surface modification were studied by analyses of thermal conductivity, tensile strength, DSC and so on. The results showed that the thermal conductivity of Al₂O₃/Co-POM materials increased with the increase of Al₂O₃ content. Noticeably, the thermal conductivity was increased to 0.46 w/(m·K) when Al₂O₃ content in the materials was 30wt%, and tensile strength was 50.63MPa. When 30wt% modified Al₂O₃ filled to the matrix resin, Al₂O₃/Co-POM materials’ thermal conductivity and tensile strength was increased to 0.63w/(m·K) and 55.89 MPa respectively, both of them improved compared with unmodified system.

In order to investigate the effects of materials’ properties with different sizes and shapes of fillers. Thermally conductive materials were prepared with Co-POM as the matrix, 5μm Al₂O₃, 30nm Al₂O₃, and 15~20μm h-BN as thermally conductive fillers. The experimental results showed that the thermal conductivity and tensile strength of h-BN/Co-POM materials were 0.39 w/(m·K) and 64.83 MPa respectively when the amount of h-BN was 8wt%. 10wt% 30nm Al₂O₃ filled Co-POM materials’ thermal conductivity was 0.38 w/(m·K), and tensile strength was 64.54 MPa. For two fillers combination system, when the amount of fillers were 20wt% and the mass ratio of Co-POM/5μm Al₂O₃/30nm Al₂O₃ was 100:10:10, the thermal conductivity was 0.43 w/(m·K), tensile strength was 56.23MPa. For another fillers combination system, 5μm Al₂O₃ and 15~20μm h-BN were used as thermally conductive fillers, and the content of fillers in materials were 20wt%. When the mass ratio of Co-POM/5μm Al₂O₃/15~20μm h-BN was 100:10:10, the thermal conductivity and tensile strength were 0.51 w/(m·K) and 53.41 MPa respectively.