【作者】 韩颖；

【导师】 张云灿；

【作者基本信息】 南京工业大学 ， 材料学， 2005， 硕士

【摘要】 采用在熔融挤出过程中提高双螺杆挤出机螺杆转速的机械力引发方法和采用添加引发剂与提高螺杆转速的复合引发方法，研究了马来酸酐(MAH)熔融接枝高密度聚乙烯(HDPE)的官能化反应；采用机械力引发方法研究了马来酸酐(MAH)和γ-(甲基丙烯酰氧基)丙基三甲氧基硅烷(A174)双单体熔融接枝高密度聚乙烯(HDPE)的官能化反应。结果表明：双螺杆挤出机的螺杆转速和接枝反应温度对产物接枝率和熔体流动速率具有重要影响；通过控制引发剂含量和提高双螺杆挤出机的螺杆转速可以抑制HDPE在接枝过程中的交联副反应，制得具有较高接枝率(Gd=0.75～1.34％)，较好熔体流动性(MI=0.3～0.6g／10min)和较低凝胶含量(≤0.9％)的接枝产物(HDPE-g-MAH)；接枝反应中第二单体A174的存在可以促进接枝反应的进行，螺杆转速的增加可同时引起产物中MAH和A174单元含量的明显增加，可制得具有较高MAH和A174单元含量和较好熔体流动性能的接枝产物(HDPE-g-MAH-A174，MAH％≥0.59％，MFR=0.3～0.53g／10min)。 采用机械共混及材料力学性能测试方法考察了接枝产物对HDPE／PA66及HDPE／GF材料力学性能的影响。结果表明：接枝产物的加入可显著改善HDPE／PA66共混材料的相容性和HDPE／GF材料的界面粘结性，提高其力学性能；且尤以机械力引发方法所得产物的改性效果最为显著；其中HDPE-g-MAH可使HDPE／PA66材料缺口冲击强度提高至原材料的6.5倍；HDPE-g-MAH-A174可使HDPE／GF材料的拉伸、弯曲和冲击强度分别提高至原材料的1.7、1.3、2.6倍。 SEM和DSC的分析结果表明：界面粘结性和试样成型冷却收缩应力对HDPE／GF材料的断面形貌具有重要影响，在材料界面粘结力较弱时，材料界面以明显的开裂缝隙为主，而在较好的界面偶联作用条件下，材料界面则存在明显的取向层结构；HDPE／GF材料的试棒厚度对此种取向层的形成及其完整程度具有重要影响；HDPE／GF材料试样基体冷却收缩应力的应变诱导结晶作用还引起了基体结晶热焓值的增加和结晶度的增大，试样界面粘结强度越大，冷却速率越更多还原

【Abstract】 In this paper, grafting of maleic anhydride(MAH) onto high density polyethylene(HDPE) performed in melt state through the mechanical force initiation by increasing the screw rotation speed of co-rotating twin-screw extruder and through a compounded initiation by adding a certain initiator and increasing the screw rotation speed was investigated; the grafting of maleic anhydride(MAH) and γ -methacryloxypropyltrimethoxysilane(A174) onto high density polyethylene(HDPE) performed in melt state through the mechanical force initiation was also investigated. The results show that with increase of the screw rotation speed and with increase of the grafting temperature, the grafting degree and melt flow index of the grafted products are obviously increased. The crosslinking reaction can be prevented easily by increasing the screw rotation speed of twin-screw extruder; the grafting degree of the product(HDPE-g-MAH) amounts to 1.34%, its melt-flow index is between 0.3～ 0.6g/10min and its gel content is less than 0.9%. The presence of A174 is helpful to improve the percentage of MAH grafting, and the grafting degree of the product(HDPE-g-MAH-A174) is greater than 0.59%; its melt-flow index is between 0.3～0.53g/10min.The effects of the grafted products on the mechanical properties of the HDPE/PA66 and HDPE/GF blends were tested by means of mechanical testing. The results show that grafted product (HDPE-g-MAH) can obviously improve the impact strength of the HDPE/PA66 blend, which is 6.5 times than that of unimproved one. And the tensile strength, flexural strength and Izod notched impact strength of the HDPE/GF blend, which contains the mechanical force initiation grafted product (HDPE-g-MAH-A174), are 1.7, 1.3 and 2.6 times than of unimproved one respectively.The effects of the interfacial bonding strength and the cooling shrinkage stress of the specimen during molding process on the morphology of the fracture specimens更多还原