振动力场下PP/CF复合材料的结构与力学性能

采用最新开发的平衡式三螺杆动态混炼挤出机在稳态与振动条件下制备了PP/CF复合材料。探究了振动力场对不同配比的PP/CF复合材料的微观结构和力学性能的影响,以及不同振动参数对PP/CF复合材料的微观结构和力学性能的影响。结果表明,振动力场的加入不仅促进了CF在PP基体中的均匀分散,而且增强了PP与CF的界面结合,从而提高了复合材料的力学性能。与此同时,强度过大的振动力场会导致复合材料中CF的平均长度下降,使其力学性能下降。当振幅A=0. 4 mm,振频f=10 Hz时,PP/CF复合材料的力学性能达到最优,此时获得的PP/CF复合材料的拉伸强度和冲击强度比在稳态挤出条件下分别提升了约28%和18%。     

动态塑化过程振动参数对聚丙烯性能的影响

采用新型液压脉振式注射机成型聚丙烯(PP)试样,探讨了塑化过程中振幅和频率对PP物理力学性能和成型过程整机能耗的影响。结果表明:保持其他工艺参数不变,在塑化过程中施加振动后,PP试样的拉伸强度提高9.8%,冲击强度提高13.8%,密度提高0.3%,整机加工能耗降低6.6%。     

塑料电磁动态塑化挤出机加工制品的力学性能

本文采用塑料电磁动态塑化剂出机挤出的条料和吹塑的薄膜进行制样,并对其试样进行力学性能测试分析,结果表明,由于在挤出加工的全过程中引入了周期性振动力场,经塑料电磁动态塑化挤出机加工的制品的力学性能得到了改善和提高,对于PP和LDPE挤出试样,拉伸强度分别提高4.2%和4.7%,对HDPE吹塑膜,纵模向拉伸强度分别提高19.2%和37.4%。     

振动力场对聚丙烯/硅灰石复合材料性能的影响

采用三螺杆动态混炼挤出机通过熔融共混制备了聚丙烯(PP)/硅灰石复合材料,研究了振动工艺参数对材料力学性能及微观形态结构的影响。结果表明,PP/硅灰石复合材料的力学性能对振动参数的响应并不是单调增加,而是存在一个最佳的响应范围。在这一范围内,其综合力学性能得到极大提高。     

三螺杆动态混炼挤出机振动强化mEPDM增韧PP的研究

三螺杆动态混炼挤出机将振动力场引入到物料的塑化混炼挤出过程,达到强化混炼和分散的目的.从实验的角度研究了三螺杆动态混炼挤出机中央螺杆的轴向振动对mEPDM增韧PP的作用规律与机理.研究发现,振动力场强化了PP/mEPDM共混物的冲击韧性;mEPDM含量不同,振动对PP/mEPDM共混物冲击强度提高的幅度亦不相同;随着振动频率或振幅的提高,PP/mEPDM共混物的冲击强度表现出先增大后减小的趋势.     

动态三螺杆加工超细碳酸钙填充聚丙烯研究

以超细碳酸钙填充聚丙烯作为研究对象,经三螺杆动态加工后,将粒料制成试样并进行力学性能测试和扫描电镜分析.研究了不同振动参数对共混物力学性能和对截面形态结构的影响规律.结果表明,与稳态相比,动态(引入振动力场)加工条件下试样的冲击强度、拉伸强度和断裂伸长率都有显著的提高.     

尼龙66/针状硅灰石复合材料的制备和性能研究

以针状硅灰石为填料,用双螺杆挤出机共混制备尼龙(PA)66/硅灰石复合材料,研究了硅灰石含量、处理方法和加工工艺对复合材料性能的影响,并观察了硅灰石共混前后和PA66/硅灰石复合材料冲击试样断面的形貌。结果表明,硅灰石用KH–560预处理时比用KH–550预处理所制备的PA66/硅灰石复合材料的力学性能好。硅灰石以侧喂料方式加入并采用较低的螺杆转速时,可使复合材料具有较高的力学性能。随着硅灰石含量的增加,复合材料的拉伸强度、弯曲强度和缺口冲击强度都大幅提高。经过1%KH560预处理的硅灰石质量分数在30%时,PA66/硅灰石复合材料的力学性能最好。     

电磁动态注射机振动参数对PP力学性能的影响

采用电磁动态注射机注塑成型PP试样,并对其进行拉伸强度、冲击强度和DSC测试,探讨振动频率和振幅对制品力学性能的影响。结果表明:施加振动后,拉伸强度和冲击强度提高;熔点向高温漂移,有利于结晶完善程度的提高。对PP注塑料,电磁动态注塑成型时最佳的振动参数范围为f=3～9Hz,A=0 10mm～0 40mm。     

振动塑化挤出对聚烯烃片材性能的影响

利用塑料电磁塑化挤出机挤出聚烯烃片材，系统研究了挤出机螺杆轴向振动对聚乙烯挤出制品结构与性能的影响。采用DSC对挤出试样的结晶结构及形态进行分析。结果表明，振动塑化挤出使聚合物挤出试样结晶度提高，结晶完善，晶片之间的连接分子数量增加，因而制品的力学性能有所提高，特别在横向上表现明显。在适当的振动条件下，高密度聚乙烯（HDPE）试样的横向拉伸强度和冲击强度分别从22．68MPa和12．7kJ／m^2提高到了25．55MPa和23．5kJ／m^2；而聚丙烯（PP）试样横向拉伸强度和冲击强度则分别提高了20％和64％。     

聚丙烯/硅灰石复合材料反应增容研究

采用马来酸酐(MAH)在聚丙烯(PP)与硅灰石之间进行反应增容,改善了PP/硅灰石复合材料的热性能和力学性能.通过扫描电子显微镜观察了复合材料冲击断面的形貌,并测试了复合材料的负荷变形温度、拉伸性能、弯曲性能和冲击性能.结果表明,在MAH质量分数不超过5%时,PP和硅灰石之间的界面结合情况明显改善,复合材料的负荷变形温度、拉伸强度、弯曲强度、弯曲弹性模量显著提高,最大值分别达到75℃、36.1 MPa、50.3MPa、2.6 GPa.     

机械力化学改性硅灰石/聚丙烯性能的研究

利用气流磨对硅灰石进行机械力化学改性，并用IR分析对改性效果进行了预评价；对比了用改性前后的硅灰石填充聚丙烯(PP)的性能。结果表明：改性后硅灰石分别为由亲水疏油性变为亲油疏水性；硬脂酸质量分数为1．5％时，改性硅灰石／PP复合材料的拉伸强度和冲击强度最好。     

Effects of interfacial adhesion on properties of polypropylene/Wollastonite composites

Wollastonite reinforced polypropylene (PP/CaSiO₃) composites were prepared by melt extrusion. A silane coupling agent and a maleic anhydride grafted PP (PP‐g‐MA) were used to increase the interfacial adhesion between the filler and the matrix. The increased adhesion observed by scanning electron microscopy (SEM) resulted in improved mechanical properties. A model was applied to describe the relationship between the interfacial adhesion and tensile properties of PP/CaSiO₃ composites. There is stronger interfacial adhesion between silane‐treated CaSiO₃ and polymer matrix containing PP‐g‐MA as a modifier. Results of dynamic mechanical thermal analysis (DMTA) showed that stronger interfacial adhesion led to higher storage modulus. The influence of CaSiO₃ particles on the crystallization of PP was studied by using differential scanning calorimetry (DSC). The introduction of CaSiO₃ particles does not affect the crystallization temperature and crystallinity of PP matrix significantly. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Effects of malonic acid treatment on crystal structure,melting behavior,morphology, and mechanical properties of isotactic poly(propylene)/wollastonite composites

Wollastonite is treated with a new surface modifier (malonic acid). The influence of malonic acid treatment on the crystallization and mechanical properties of polypropylene (PP)/wollastonite composites has been studied. The results of differential scanning calorimetry, wide angle X‐ray diffractometry, and polarized light microscopy prove that malonic acid‐treated wollastonite increases the relative content of β‐crystal form of PP. The scanning electron microscopy shows that malonic acid‐treated wollastonite has better compatibility with PP matrix than the untreated wollastonite. Higher β‐phase contents, smaller spherulite sizes, and better compatibility with PP matrix of the composites containing malonic acid‐treated wollastonite result in improved impact strength and tensile strength, but lower flexural modulus. The results of Fourier transform infrared spectroscopy show that malonic acid reacts with the Ca²⁺ of wollastonite to form the calcium malonate, which acts as an effective β‐nucleating agent. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers     

EPDM/POE/PP热塑性硫化橡胶材料的制备及性能研究

以三元乙丙橡胶(EPDM)/乙烯-辛烯共聚物(POE)/聚丙烯(PP)为原料,在PP含量固定的情况下,将POE部分取代EPDM,采用动态硫化技术制备出EPDM/POE/PP三元热塑性橡胶材料(TPV),研究不同含量的POE对材料力学性能、流变性能和微观形貌的影响。结果显示,随着POE含量的增加,三元TPV材料的硬度和熔体质量流动速率不断增大;拉伸强度和断裂伸长率呈线性增大,当EPDM/POE/PP比例为45/40/15时,材料力学性能达到最大值。流变性能和微观形貌分析结果表明,EPDM/POE/PP三元TPV材料具有良好的综合性能。     

聚丙烯/溴化丁基橡胶合金的力学性能研究

采用动态硫化工艺,制备聚丙烯(PP)/溴化丁基橡胶(BIIR)合金,研究了PP与BIIR的质量比、填充补强剂凹凸棒土(AT)和马来酸酐接枝聚丙烯相容剂(PP-g-MAH)的用量对合金力学性能的影响。结果表明,不加AT时,随着BIIR用量的增加,PP/BIIR的硬度减小,拉伸强度不断降低,断裂伸长率和冲击强度显著增大;当PP与BIIR的质量比为90∶10且AT的用量为5份时,PP/BIIR合金的性能最佳;PP-g-MAH的加入可以改善合金的力学性能。     

The Effect of Vibration on Mechanical Properties of Blends of EPDM/PP in a Tri-screw Dynamic Mixing Extruder

The effects of vibration force field on mechanical properties of blends of EPDM/PP during process of plastics in tri-screw dynamic mixing extruders were investigated experimentally. It was found that vibration force field enhanced mechanical properties of blends of EPDM/PP, and the amplitude of enhancement varied as EPDM content varying. The yangs modulus, the impact strength and the tensile strength were improved the maximum 17, 28, and 17.3%, respectively under dynamic conditions than that under steady conditions. Mechanical properties of blends of EPDM/PP represented a tendency of a rising followed by a fall with the increase of vibration frequency and amplitude.     

Improvement of toughness properties of polypropylene/wollastonite composites using an interface modifier

The effects of type of processing of polypropylene (PP)/wollastonite composites on mechanical properties and dispersion state were investigated. The concentration in weight of the filler in the compounds was of 2.5%, 5%, and 10%, respectively. Stearic acid was used as an interface modifier for the PP–wollastonite system. Wollastonite was also modified with stearic acid. The infrared spectra did not show any chemical changes between unmodified and modified wollastonites. The interactions between wollastonite and stearic acid were mainly physical. The compounds with interface modifier (stearic acid) showed the higher values in impact strength and elongation at break, as well as the best dispersion state. Qualitative chemical analysis on scanning electronic microscopy detected the presence of the acid stearic in the interface. POLYM. COMPOS., 35:1184–1192, 2014. © 2013 Society of Plastics Engineers     

动态硫化聚丙烯的研究

研究了聚丙烯动态硫化体系及工艺对聚丙烯复合材料力学性能熔体强度的影响，结果表明，交联剂，闻并助剂、改性剂，加料程度及加工温度是影响Ｉｚｏｄ冲击强度和熔体强度的主要因素。     

Studies on morphology,mechanical, thermal,and dynamic mechanical behavior of extrusion blended polypropylene and thermotropic liquid crystalline polymer in presence of compatibilizer

Polypropylene was melt blended in a single screw extruder with thermo tropic Vectra B‐950 liquid crystalline polymer (copolyester amide) in different proportions in presence of 2% of EAA, ethylene‐acrylic acid copolymer (based on PP) as a compatibilizer. The mechanical properties of such compatibilized blends were evaluated and compared in respect of their Young's Modulii, Ultimate tensile strength, percent elongation at break, and toughness to those of Pure PP. The Morphology was studied by using a polarizing light microscope (PLM) and Scanning electron microscope (SEM). The Thermal characterization of these blends were carried out by differential scanning calorimeter (DSC).The mechanical properties under dynamic conditions of such compatibilized blends and pure PP were studied by dynamic mechanical analyzer (DMA). Mechanical analysis (Tensile properties) of the compatibilized blends displayed improvements in Modulii and ultimate tensile strength (UTS) of PP matrix with the incorporation of 2–10% of LCP incorporation. The development of fine fibrillar morphology in the compatibilized PP/LCP blends had large influence on the mechanical properties. Differential scanning calorimeter (DSC) studies indicated no remarkable changes in the crystalline melting temperature of the blends with respect to that of pure PP. However, an increase in the softening range of the blends over that of PP was observed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

振动力场下PP增强管材的制备及性能研究

采用电磁动态塑化挤出机挤出聚丙烯（PP）管材,通过爆破压力测试、拉伸性能测试、差示扫描量热（DSC）分析和X射线衍射（XRD）分析研究了振动频率和振幅对PP管材结构与力学性能的影响。力学性能测试结果表明,振动挤出PP管材的周向强度有了显著提高,实现了管材的双向自增强。与稳态挤出的PP管材相比,振动挤出PP管材的爆破压力最大提高了27．03％,轴向拉伸屈服强度最大提高了7．3％。DSC分析和XRD分析表明,振动挤出的PP管材结晶度提高,熔点升高,结晶完善,晶粒变小,有利于管材力学性能的提高。