POE-g-MAH反应性增容HDPE/PA66共混合金性能研究

以乙烯-辛烯共聚物接枝马来酸酐(POE-g-MAH)作为高密度聚乙烯(HDPE)/尼龙66(PA66)共混合金的反应性增容剂,采用熔融挤出法制备了HDPE/PA66/POE-g-MAH共混合金。研究了POE-g-MAH用量对共混合金形态结构、力学性能、流变性能和热致形状记忆性能的影响。结果表明:通过POE-g-MAH的反应性增容作用,改善了HDPE/PA66合金的界面黏结,促进了分散相粒子的细化,显著提高了合金的力学和热致形状记忆性能,并缩短了塑化时间。     

相容剂对稻糠/聚丙烯复合材料加工性能和尺寸稳定性的影响

通过反应挤出法制备了马来酸酐接枝乙烯-辛烯共聚物(POE-g-MAH)相容剂,研究了POE-g-MAH对稻糠/聚丙烯(PP)复合材料力学性能、加工性能和尺寸稳定性的影响。结果表明:POE-g-MAH增容效果优于马来酸酐接枝三元乙丙橡胶(EPDM-g-MAH)和马来酸酐接枝聚丙烯(PP-g-MAH),能显著提高复合材料的拉伸强度、冲击强度、弯曲强度和尺寸稳定性;EPDM-g-MAH和PP-g-MAH对复合材料加工性能影响不大,而POE-g-MAH使稻糠/PP复合材料的最大转矩和平衡转矩明显降低,加工性能得到改善。     

HDPE/木粉复合材料的性能研究

研究了不同种类的增容剂对高密度聚乙烯(HDPE)木/粉复合材料性能的影响,并研究了增容剂含量、木粉含量对复合材料力学性能及形态结构的影响。结果表明,HDPE木/粉复合材料的拉伸强度、弯曲强度均随马来酸酐接枝HDPE(HDPE-g-MAH)含量的增加而增大;复合材料的缺口冲击强度随甲基丙烯酸缩水甘油酯接枝低密度聚乙烯的增加而提高;复合材料的拉伸强度、弯曲强度随木粉含量的增加而增大;而缺口冲击强度则随木粉含量的增加呈降低趋势。     

HDPE/SCF/POE-g-MAH复合材料的制备与性能

以高密度聚乙烯(HDPE)为基体,以短切碳纤维(SCF)为增强剂,马来酸酐接枝乙烯-辛烯共聚物(POE-gMAH)为相容剂,通过熔融挤出制备了HDPE/SCF/POE-g-MAH复合材料。测试了HDPE/SCF/POE-g-MAH复合材料的力学性能、流变性能和断面形貌。结果表明:加入适量的SCF和POE-g-MAH,复合材料的力学性能明显得到提高。随着POE-g-MAH含量的增加,HDPE/SCF/POE-g-MAH复合材料的剪切黏度得到提高。POE-g-MAH的加入,提高了复合材料中SCF和HDPE之间的相容性。     

γ-辐照对HDPE/PUR-T共混体系性能的影响

以高密度聚乙烯(HDPE)和热塑性聚氨酯弹性体(PUR-T)为主要原料,以马来酸酐接枝(乙烯/乙酸乙烯酯)共聚物(E/VAC-g-MAH)为增容剂,采用双螺杆挤出熔融共混技术制备了HDPE/PUR-T和HDPE/PUR-T/(E/VAC-g-MAH)等共混材料,利用60Co-γ射线源在较低辐照剂量(小于等于25 kGy)下对共混材料进行了γ-辐照。考察了γ-辐照、增容剂E/VAC-g-MAH对共混体系的力学性能、界面形态与熔体流动性能的影响。结果表明,同时采用γ-辐照与使用增容剂E/VAC-g-MAH两种增容方法,可以有效地改善HDPE/PUR-T的力学性能和相容性。     

HDPE含量对PA1012/POE-g-MAH/HDPE共混物性能的影响

采用双螺杆挤出机,通过熔融共混法制备了尼龙1012(PA1012)/马来酸酐接枝乙烯-辛烯共聚物(POEg-MAH)/高密度聚乙烯(HDPE)合金材料。固定PA1012/POE-g-MAH/HDPE的含量比为80/(20-x)/x(x=0~20),通过机械性能、扫描电镜(SEM)、熔体质量流动速率(MFR)测试,考查了HDPE含量对POE-g-MAH增韧PA1012性能的影响。当(20-x)∶x小于3∶2时,随着HDPE含量的提高,合金材料的冲击强度、弯曲模量均增大。当PA1012/POE-g-MAH/HDPE的含量比为79.8/12/8时,与20%POE-g-MAH增韧PA1012相比,悬臂梁缺口冲击强度提高了30.4%,弯曲模量提高了19.8%,有效实现了增韧PA1012的刚韧平衡。     

相容剂对HDPE/PC共混合金性能的影响

采用熔融接枝方法制备马来酸酐接枝高密度聚乙烯(HDPE-g-MAH)和丙烯酸接枝高密度聚乙烯(HDPE-g-AA)，比较了这2种相容剂对HDPE／聚碳酸酯(Pc)共混合金体系的增容效果，着重研究了接枝单体、引发剂对HDPE接枝物的接枝率和熔体流动速率的影响及HDPE接枝物用量对HDPE／PC合金力学性能的影响。结果表明：HDPE-g-MAH相容剂的增容效果较好。用量为15份时使HDPE／PC合金缺口冲击强度提高了30％。     

HDPE/CB/PA6复合材料的导电与力学性能研究

为了改善尼龙6低温与干态存在着冲击强度低、纤维状易于电荷富集的缺陷,制备了高密度聚乙烯(HDPE)/导电炭黑(CB)/尼龙6(PA6)复合材料。首先制备了HDPE/CB共混物作为功能改性剂,再以马来酸酐接枝乙烯-辛烯共聚物(POE-g-MAH)为增容剂,通过双螺杆挤出机熔融共混制备了HDPE/CB/PA6复合材料。通过扫描电子显微镜(SEM)、万能试验机、高阻计等方法,研究了添加增容剂和HDPE与PA6配比以及导电炭黑粒子含量对复合材料力学性能和导电性能的影响。结果表明,加入5 phr的增容剂POE-g-MAH,明显提高了HDPE与PA6的界面黏附力,复合材料相容性较好;当HDPE与PA6的质量比为35/65时,复合材料的断裂伸长率从纯PA6的88%增加到251%,缺口冲击强度从12.5 kJ/m~2增加到53.7 kJ/m~2;当导电炭黑的含量增加到2.5 phr时,复合材料的室温体积电阻率降低了7~10个数量级,约为10~8Ω·cm。     

硅烷接枝HDPE/纳米SiO_2复合材料的制备与性能

将经表面处理后的纳米SiO2和硅烷接枝高密度聚乙烯(HDPE)熔融共混制得硅烷接枝HDPE/纳米SiO2复合材料,并对其结晶行为、力学性能及热性能进行了研究。结果表明:与HDPE相比,硅烷接枝HDPE/纳米SiO2复合材料的结晶度降低约17%;在纳米粒子含量为6%时,热分解温度提高了15℃;在纳米粒子含量为10%时,体系的拉伸强度提高了25%。     

HDPE熔融接枝GMA/St及其增容HDPE/PET合金性能的研究

利用HAAKE流变仪,采用熔融接枝法分别制备了甲基丙烯酸缩水甘油酯(GMA)、GMA/苯乙烯(St)接枝高密度聚乙烯(HDPE),将所得接枝物HDPE-g-GMA和HDPE-g-(GMA-co-St)作为HDPE/PET共混合金的反应性增容剂,研究了其对体系力学性能和热致形状记忆性能等的影响。结果表明:采用GMA/St双组分单体具有较高的接枝率,生成的接枝物对HDPE/聚对苯二甲酸乙二醇酯(PET)共混合金的增容效果较好;提高了体系的力学性能和热致形状记忆性能,且HDPE-g-(GMA-co-St)含量为5～10phr时,合金具有较好的综合性能。     

蒙脱土及粉煤灰玻璃微珠对超高分子量聚乙烯/高密度聚乙烯复合材料流动性能的影响

在双螺杆挤出机上制备了超高分子量聚乙烯/高密度聚乙烯复合材料,选择蒙脱土及粉煤灰玻璃微珠对超高分子量聚乙烯/高密度聚乙烯复合材料进行流动改性,采用XRD研究了蒙脱土在复合材料中的结构,研究了蒙脱土及粉煤灰玻璃微珠对复合材料流动性能的影响。研究结果表明:在低填充量下,蒙脱土及粉煤灰玻璃微珠可以提高超高分子量聚乙烯/高密度聚乙烯复合材料的流动性能。蒙脱土及粉煤灰玻璃微珠协同改性可以明显提高复合材料的流动性能。     

Melt Rheological and Thermoresponsive Shape Memory Properties of HDPE/PA6/POE-g-MAH Blends

High density polyethylene (HDPE)/nylon6 (PA6) blends were prepared by means of melt extrusion and using ethylene – octane copolymer graft maleic anhydride (POE-g-MAH) as a reactive compatibilizer. Phase morphology, rheological and thermoresponsive shape memory properties of the blends had been studied. The results showed that addition of POE-g-MAH could increase compatibility and phase-interfacial adhesion between HDPE and PA6, decrease the temperature sensitivity of the melt, improve the shape memory property and processability of HDPE/PA6 blends. The shape recovery rate of HDPE/PA6/POE-g-MAH (80/20/10) blend is 96.5% when the stretch ratio is 75% and optimal shape recovery response temperature is 135°C.     

PA66/EPDM-g-MAH/CaCO_3复合材料的性能

采用熔融挤出过程中改变螺杆转速和添加引发剂的复合引发方法制备了马来酸酐接枝三元乙丙橡胶(EPDM-g-MAH),将其单独或与CaCO_3混合后改性聚酰胺66(PA66)。通过滴定分析、红外表征和熔体流动速率(MFR)测定等方法研究了175℃条件下螺杆转速对EPDM-g-MAH的MFR和接枝率的影响。探讨了接枝物和CaCO_3对PA66力学性能、热变形温度的影响。研究结果表明,改变螺杆转速可以有效控制接枝物凝胶含量(1%),提高接枝率和MFR;当接枝物用量为30份时,PA66/EPDM-g-MAH复合材料的简支梁缺口冲击强度为34.24 k J/m2,是纯PA66的3.89倍;当CaCO_3用量小于15份时,两种CaCO_3与EPDM-g-MAH均能够协同增韧PA66,当PA66/EPDM-g-MAH/CaCO_3配比为100/30/10时,加入超细活性重质CaCO_3及纳米CaCO_3的复合材料的简支梁缺口冲击强度均达到最大值,分别为纯PA66的4.35倍和4.10倍,超细活性重质CaCO_3的作用优于纳米CaCO_3。超细活性重质CaCO_3用量为20份时,PA66/EPDM-g-MAH复合材料的弯曲强度、热变形温度及MFR最佳,分别为59.42 MPa、81.6℃及9 g/(10 min)。     

Preparation of HDPE/UHMWPE/MMWPE blends by two-step processing way and properties of blown films

Summary Blends of high density polyethylene (HDPE) and ultra high molecular weight polyethylene (UHMWPE) were prepared by two-step processing way. Middle molecular weight polyethylene (MMWPE) as a fluidity modifier and compatilizer was added into UHMWPE in the first step, and then modified UHMWPE and HDPE were blending extruded to prepare the HDPE/UHMWPE/MMWPE blends used for blown films. The mechanical test of the blown films revealed that when the content of MMWPE in modified UHMWPE was 40wt% and the content of UHMWPE in the blends was 20 wt%, the film had the optimal mechanical properties. The tensile strength and tear strength of the film increased by 50% and 21%, respectively, compared with those of pure HDPE film. Rheological curves indicated that the melt torque and the apparent viscosity of the HDPE/UHMWPE/MMWPE blends made by two-step processing way both greatly reduced than other blends. The results from DSC suggested that the blends by two-step processing way may form more stable and perfect co-crystallization. PLM (polarized light microscopy) and SEM micrographs revealed that two-step processing way can improve the surface morphology of the films and make the dispersion of UHMWPE particles in HDPE increase.     

Thermal and mechanical properties of UHMWPE/HDPE/PCL and bioglass filler: Effect of polycaprolactone

Polymeric composites based on polyethylene, high-density polyethylene (HDPE) and ultra-high-molecular-weight polyethylene (UHMWPE) with polycaprolactone (PCL) and a ceramic filler (bioglass type) were studied in terms of their thermal and mechanical behavior. Two polyethylene ratios (10/90 and 30/70% wt/wt of UHMWPE/HDPE) and two PCL content ratios (5% and 10% wt/wt) were used. The obtained composites were characterized by differential scanning calorimetry, melt flow index, Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction. The results indicate a nonchemical interaction between polyethylene, especially the UHMWPE, and PCL and that the composites' thermal transitions vary from the parent polymers and depend on the PCL concentration. The PCL's melting temperature in the composite was reduced, showing a new one. Also, the melting enthalpy of polyethylene was reduced when the concentration of PCL increased. The mechanical behavior depends on both the polyethylene ratio and the PCL content. The composite with 30% wt/wt of UHMWPE and 10% wt/wt of PCL showed the highest toughness value due to the good interaction between polymers. These new composites may be attractive for biomedical applications and could be evaluated, for example, as materials for prostheses.     

UHMWPE/HDPE共混物的流动性及力学性能的研究

采用不同MFR的HDPE与UHMWPE进行熔体共混。结果表明UHMWPE／HDPE共混物流动性和力学性能的变化受体系组成、熔体粘度比等因素的影响较大。HDPE的MFR过高、过低或用量过多，均不利于共混物流动性及综合力学性能的改善。当HDPE作为分散相时，易于实现向UHMWPE高粘弹粒子的渗透、分散及结合，共混物的．MFR及拉伸屈服强度、断裂强度、断裂伸长率均比UHMWPE有提高，共混物表现出协同效应；当UHMWPE为分散相或二者熔体粘度比差异过大时，混合效果变差，共混物综合力学性能下降；在某些中间配比下，二者表现出增链缠结效应，共混物MFR明显降低。     

PA66/POE-g-MAH/纳米SiO_2复合材料的制备及性能

通过熔融共混的方法制备PA66/POE-g-MAH/纳米SiO_2三元共混体系,研究纳米SiO_2、POE-g-MAH对PA66力学性能的影响.研究结果表明:POE-g-MAH与纳米SiO_2对PA66有协同增韧效应,当PA66/POE-g-MAH/纳米SiO_2配比为100/30/0.1时,复合体系的缺口冲击强度达到最大,为纯PA66的10.9倍,为PA66/POE-g-MAH(100/30)二元体系的1.8倍;低温缺口冲击强度也达到最大,为纯PA66的6.3倍.用扫描电镜观察分析冲击断口形态.     

超高分子量聚乙烯/高密度聚乙烯共混物的低温冲击研究

通过DSC、SEM和动态流变法分析超高分子量聚乙烯/高密度聚乙烯(UHMWPE/HDPE)共混物的相容性。结果表明:UHMWPE和HDPE具有良好的相容性。UHMWPE/HDPE共混物是典型的假塑性流体,当HDPE的质量分数逐渐增大,共混物的复数黏度明显减小,其流动性变好。UHMWPE能够显著提高共混物的低温冲击性能,当UHMWPE含量超过40%,共混物在-60℃的缺口冲击强度在70 kJ/m²以上。当UHMWPE含量为50%,共混物的熔体流动速率为0.12 g/10min,-60℃缺口冲击强度达到77 kJ/m²,使加工性和低温冲击性能达到平衡。     

BP神经网络在POE-g-MAH/HDPE增韧PA6研究中的应用

运用BP神经网络研究了马来酸酐接枝乙烯-辛烯共聚物(POE-g-MAH)/高密度聚乙烯(HDPE)对尼龙6(PA6)的增韧作用,并在此基础上建立了PA6/POE-g-MAH/HDPE复合材料各组分用量与复合材料冲击强度的关系模型。结果表明:该模型和实验结果基本吻合,可信度较高;当POE-g-MAH质量分数为12%,HDPE质量分数为16%时,PA6的缺口冲击强度达到95.02 kJ/m2。