丁基橡胶/聚丙烯热塑性硫化胶的结晶和动态力学性能研究

采用动态硫化法制备丁基橡胶(IIR)/聚丙烯(PP)热塑性硫化胶(TPV),研究橡塑比对TPV结晶性能、动态力学性能和物理性能的影响,并与IIR/PP简单共混胶进行对比。结果表明:与简单共混胶和PP相比,TPV的结晶温度和熔点较低,随着橡塑比的增大,TPV的结晶温度降低,结晶度减小,结晶时间延长;随着橡塑比的增大,TPV的储能模量总体降低,且TPV中IIR相的玻璃化转变温度向高温方向移动,PP相的损耗峰减弱,两相相容性增强;在-60～-30℃范围内,与相同橡塑比TPV相比,简单共混胶的储能模量较低,IIR和PP两相相分离明显;与简单共混胶相比,TPV的硬度、拉伸强度和拉断伸长率较大,溶胀比较小;随着橡塑比的增大,TPV的硬度和拉伸强度减小,溶胀比和拉断伸长率呈增大趋势。     

动态硫化法制备多壁碳纳米管/热塑性硫化胶复合材料的热电性能（英文）

采用动态硫化法制备出多壁碳纳米管(MWCNTs)/热塑性硫化胶(TPV)复合材料。结果表明,MWCNTs/TPV复合材料具有"海岛"相结构,丁基橡胶相以微米级颗粒分散于聚丙烯(PP)相中,MWCNTs则主要分散于PP相及橡塑两相界面。当MWCNTs的质量分数达到渗滤阈值(3%)时可形成MWCNTs网络,致使复合材料的体积电阻率急剧减小,即MWCNTs/TPV复合材料的热电性能均因MWCNTs的存在而得到明显改善。     

石墨烯/多壁碳纳米管/热塑性硫化胶复合材料的制备及性能（英文）

通过熔融接枝共混制备了石墨烯(Ge)/多壁碳纳米管(MWCNTs)/聚丙烯(PP)母粒,然后与丁基橡胶动态硫化制备了Ge/MWCNTs/热塑性硫化胶(TPV)复合材料,考察了Ge/MWCNTs/TPV复合材料的相态结构、热电性能和力学性能。结果表明,Ge/MWCNTs作为异相成核剂能够提高PP的结晶温度;Ge/MWCNTs/TPV复合材料呈现"海-岛"结构,Ge和MWCNTs在PP相和橡塑两相界面分散均匀、与基体结合能力强。加入质量分数均为3%的Ge和MWCNTs时,Ge/MWCNTs/TPV复合材料的直流电导率提高5个数量级,热导率提高了36.7%,拉伸强度达17.3 MPa,扯断伸长率达260%。     

Preparation and properties of graphene/multi-walled carbon nanotube/thermoplastic vulcanizate composites

通过熔融接枝共混制备了石墨烯（Ge）/多壁碳纳米管（MWCNTs）/聚丙烯（PP）母粒,然后与丁基橡胶动态硫化制备了Ge/MWCNTs/热塑性硫化胶（TPV）复合材料,考察了Ge/MWCNTs/TPV复合材料的相态结构、热电性能和力学性能。结果表明,Ge/MWCNTs作为异相成核剂能够提高PP的结晶温度;Ge/MWCNTs/TPV复合材料呈现“海-岛”结构,Ge和MWCNTs在PP相和橡塑两相界面分散均匀、与基体结合能力强。加入质量分数均为3%的Ge和MWCNTs时,Ge/MWCNTs/TPV复合材料的直流电导率提高5个数量级,热导率提高了36.7%,拉伸强度达17.3 MPa,扯断伸长率达260%。     

聚丙烯(PP)基介电复合材料的研究

以聚丙烯(PP)为基体,多壁碳纳米管(MWCNTs)为填料,采用微纳层叠共挤的方法制备了PP/MWCNTs介电复合材料,分别对不同结构的介电复合材料中MWCNTs分散情况及其对复合材料介电性能的影响进行了研究。结果表明,与纯PP相比,MWCNTs的添加能够明显提高PP基复合材料的介电常数;具有层结构的PP/MWCNTs介电复合材料,分散相MWCNTs比在单层PP基复合材料中分散更好,复合材料介电常数提高1.2倍。     

辛基酚醛树脂动态硫化丁基橡胶/聚丙烯 热塑性硫化胶的性能研究

选用辛基酚醛树脂硫化剂,采用动态硫化法制备丁基橡胶(IIR)/聚丙烯(PP)热塑性硫化胶(TPV),研究辛基酚醛树脂硫化剂用量对TPV的流变性能、物理性能、动态力学性能和微观形貌的影响,并与IIR/PP简单共混胶进行对比。结果表明:随着辛基酚醛树脂硫化剂用量的增大,动态硫化过程中TPV熔体的转矩逐渐增大,TPV的储能模量和交联密度提高;橡塑简单共混胶的物理性能最差;随着辛基酚醛树脂硫化剂用量的增大,TPV的硬度增大,拉伸强度和拉断伸长率呈先提高后降低趋势,热老化后各项物理性能变化规律与老化前相同;橡塑简单共混胶以及采用少量辛基酚醛树脂硫化剂动态硫化TPV均有2个损耗峰,随着辛基酚醛树脂硫化剂用量的增大,TPV中IIR相的玻璃化转变温度向高温方向移动;橡塑简单共混胶断面比较平整,脊线少,随着辛基酚醛树脂硫化剂用量的增大,TPV断面变得粗糙且脊线有增多趋势。     

废旧胶粉/聚丙烯/环氧树脂复合材料结构和性能的研究

制备废旧胎面胶粉(WRP)/聚丙烯(PP)/环氧树脂(EP)复合材料,并研究EP用量对复合材料结构和性能的影响。结果表明,EP的交联网络与WRP分子链形成互穿网络结构,增大了WRP/PP/EP复合材料的交联程度。随着EP用量的增大,WRP/PP/EP复合材料的拉伸强度和拉断伸长率先增大后减小,在EP用量为0. 3份时达到最大值;熔体流动速率降低;凝胶质量分数增大。添加EP后,WRP相与PP相的玻璃化温度逐渐接近,两者的相容性提高;WRP相的热质量损失速率减小,PP相的热质量损失速率增大;复合材料的断面变得平滑,孔洞减少,界面相容性提高,EP用量为0. 3份时WRP相与PP相的相容性最好。     

废旧胶粉/聚丙烯/环氧树脂复合材料的结构和性能研究

制备废旧胎面胶粉(WRP)/聚丙烯(PP)/环氧树脂(EP)复合材料,并研究EP用量对复合材料结构和性能的影响。结果表明,EP的交联网络与WRP分子链形成互穿网络结构,增大了WRP/PP/EP复合材料的交联程度。随着EP用量的增大,WRP/PP/EP复合材料的拉伸强度和拉断伸长率先增大后减小,在EP用量为0. 3份时达到最大值;熔体流动速率降低;凝胶质量分数增大。添加EP后,WRP相与PP相的玻璃化温度逐渐接近,两者的相容性提高;WRP相的热质量损失速率减小,PP相的热质量损失速率增大;复合材料的断面变得平滑,孔洞减少,界面相容性提高,EP用量为0. 3份时WRP相与PP相的相容性最好。     

动态硫化工艺对丁基橡胶/聚丙烯热塑性硫化胶性能的影响

考察了3种不同动态硫化工艺(M 1、M 2和M 3)对丁基橡胶(IIR)/聚丙烯(PP)热塑性硫化胶(TPV)结构与性能的影响,并考察了转子转速和动态硫化时间对IIR/PP TPV物理机械性能的影响。结果表明,不同动态硫化工艺制备的TPV的Payne效应均随着应变的增大而减小,采用M 3工艺制备的TPV的网络结构最强。采用3种工艺制备的TPV的拉伸强度由大到小依次为:M 3、M 2、M 1。采用M 2和M 3工艺制备的TPV中IIR与PP相容性较好。不同动态硫化工艺制备的TPV中IIR均呈不规则长条状分散在PP中,采用M 1工艺制备的TPV中交联IIR颗粒的尺寸最大,采用M 3工艺制备的TPV中交联IIR相颗粒和滑石粉填料分散较均匀。随着动态硫化过程中转子转速的提高及动态硫化时间的延长,采用M 3工艺制备的TPV的拉伸强度和扯断伸长率均先增加后减小。当转子转速为80 r/min、动态硫化时间为5 min时,IIR/PP TPV的物理机械性能较好。     

丁基橡胶/聚丙烯动态硫化热塑性弹性体的制备和性能研究

以丁基橡胶(IIR)和聚丙烯(PP)为基体材料,利用动态硫化的方法制备了丁基橡胶/聚丙烯热塑性弹性体(IIR/PP TPV),主要研究了硫化剂用量和制备工艺参数对IIR/PP TPV力学性能和动态力学性能的影响。结果表明,随着硫化剂用量的增加,IIR/PP TPV的力学性能得到提高,硫化剂用量为9 phr时,IIR/PP TPV的综合性能优异;动态硫化温度为180℃时,IIR/PP TPV有优异的力学性能和阻尼性能;随着动态硫化时间的增加,拉伸强度呈现先增加后减小而断裂伸长率呈现逐渐增大的趋势,硫化时间超过10 min之后,IIR/PP TPV的阻尼性能开始下降,当硫化时间为10 min时,IIR/PP TPV的力学性能和动态力学性能优异。     

酒石酸改性BT增强PP复合材料导热与介电性能

以酒石酸为改性剂,对钛酸钡(BT)颗粒进行表面改性,制备了聚丙烯(PP)/纳米氧化铝(Al2O3)/改性BT系列3相复合材料.通过傅里叶红外光谱、扫描电子显微镜、介电频谱仪、导热分析仪对复合材料的红外光谱、微观形貌、介电性能、导热性能等进行分析表征.结果表明,酒石酸对BT颗粒的表面改性能有效改善BT、Al2O3等无机填...     

Fabrication and characterization of homogeneous composites of polypropylene and multiwalled carbon nanotubes

The polypropylene‐grafted multiwalled carbon nanotubes (PP‐MWCNTs) were produced from the reaction of PP containing the hydroxyl groups and MWCNTs having 2‐bromoisobutyryl groups. The PP‐MWCNTs had a significantly rougher surface than the original MWCNTs. PP‐MWCNTs had PP layers of thickness 10–15 nm on the outer walls of the MWCNTs. PP/PP‐MWCNT composites and PP/MWCNT composites were prepared by solution mixing in o‐xylene. Unlike PP/MWCNT composites, PP‐MWCNTs were homogeneously dispersed in the PP matrix. As a consequence, the thermal stability and conductivity of PP/PP‐MWCNT composites were dramatically improved even if only 1 wt % of PP‐MWNTs was added to the PP matrix. The good miscibility of PP and PP‐MWCNTs plays a critical role in the formation of the homogeneous composites and leads the high thermal stability and conductivity. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

强剪切流动下聚丙烯基复合材料介电性能和结构演变的研究

研究了多壁碳纳米管(MWCNT)、线型低密度聚乙烯(LLDPE)和强剪切流动场对聚丙烯(PP)/MWCNT/LLDPE复合材料的导电性能、结晶性能、力学性能和介电性能的研究。结果表明,PP/MWCNT复合材料随着MWCNT含量的提高,导电性能逐步改善,导电逾渗值约为1.8%,而第二分散相LLDPE的引入使复合材料的导电性能表现出了先降低后升高的现象,并且随着LLDPE含量的增加,MWCNT逐步向LLDPE内部迁移,构成了双连续结构。复合材料经过固态口模拉伸的强剪切流动场之后,随着拉伸速率从10 mm/min增加到300 mm/min的过程中,复合材料的融化温度逐渐向高温方向偏移,表现出了片层厚度增加的现象。复合材料内部分子链取向和纤维结构的形成,能够显著提高复合材料的拉伸强度和介电性能,拉伸强度提高从约50 MPa提高到了约240 MPa,提高了约380%。MWCNT和强剪切流动场的引入也使复合材料的介电常数大幅提升。     

Fabrication and characterization of NBR/MWCNT composites by latex technology

To develop a rubber composite with excellent electrical properties, a sort of synthetic rubber, acrylonitrile butadiene rubber (NBR) with CN dipoles as matrix, multi‐walled carbon nanotubes (MWCNTs) as filler, was synthesized. NBR composites reinforced with 0.5, 1.5, 3, 10, and 20 phr MWCNT contents were fabricated by latex technology. The electrical conductivity, dielectric characteristics, and electromagnetic interference (EMI) shielding effectiveness at room temperature of NBR/MWCNT composites were investigated. MWCNTs were found well dispersed into NBR matrix even for 20 phr content by FESEM observation. The electrical conductivity increased with an increment of MWCNT content. The dielectric constant was over 10⁴ at 10³ Hz frequency for 10 and 20 phr MWCNTs‐reinforced NBR composites. It was attributed to the increased electrons and interface polarization. The improved conductivity and dielectric permittivity resulted in an enhanced EMI shielding effectiveness. The EMI shielding effectiveness reached 26 dB at 16.7 GHz frequency for NBR/20 phr MWCNT composite with 1.0 mm thickness. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers     

有机蒙脱土/丁基橡胶/聚丙烯热塑性硫化胶的制备与性能

采用动态硫化法制备了有机蒙脱土(OMMT)/丁基橡胶(IIR)/聚丙烯(PP)热塑性硫化胶(TPV),考察了OMMT的用量和IIR/PP的质量比对TPV的物理机械性能、动态力学性能及热性能的影响.结果表明,当OMMT的用量为20份时,TPV的物理机械性能较佳,Payne效应最弱,OMMT均匀地分布在基体中,阻尼性能较好...     

Preparation and properties of polyurethane/multiwalled carbon nanotube nanocomposites by a spray drying process

A spray drying approach has been used to prepare polyurethane/multiwalled carbon nanotube (PU/MWCNT) composites. By using this method, the MWCNTs can be dispersed homogeneously in the PU matrix in an attempt to improve the mechanical properties of the nanocomposites. The morphology of the resulting PU/MWCNT composites was investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). SEM and TEM observations illustrate that the MWCNTs are dispersed finely and uniformly in the PU matrix. X‐ray diffraction results indicate that the microphase separation structure of the PU is slightly affected by the presence of the MWCNTs. The mechanical properties such as tensile strength, tensile modulus, elongation at break, and hardness of the nanocomposites were studied. The electrical and the thermal conductivity of the nanocomposites were also evaluated. The results show that both the electrical and the thermal conductivity increase with the increase of MWCNT loading. In addition, the percolation threshold value of the PU composites is significantly reduced to about 5 wt % because of the high aspect ratio of carbon nanotubes and exclusive effect of latex particles of PU emulsion in dispersion. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Effects of multi‐walled carbon nanotubes and conductive carbon black on electrical,dielectric, and mechanical properties of epoxidized natural rubber composites

The influence of multi‐walled carbon nanotubes (MWCNTs) and conductive carbon black (CCB) on cure, electrical, dielectric, and mechanical properties of epoxidized natural rubber (ENR) composites was investigated. It was found that short MWCNTs (S‐MWCNTs) with low loading significantly affected the cure characteristics in a way similar to high loading of CCB. Moreover, the ENR/S‐MWCNTs composites exhibited high AC conductivity, dielectric constant, and dielectric loss tangent (tan δ ) compared to the ENR/CCB and ENR/L‐MWCNTs (long MWCNTs) composites. In addition, the S‐MWCNTs composites showed the lowest percolation threshold concentration, defined as the lowest loading to form conductive paths in the insulating ENR matrix. This might be attributed to the comparatively high interfacial polarization, with good dispersion and distribution, of the S‐MWCNTs in ENR matrix. These characteristics were confirmed by TEM imaging and by a high bound rubber content, corroborating strong filler–rubber interactions in the ENR/S‐MWCNTs composites. However, the L‐MWCNTs composites showed the lowest electrical and other related properties, despite the highest aspect ratio and specific surface area of this filler. This might be because of the flocculation of nanotubes by mutual entanglement, leading to a poor uneven distribution in the ENR matrix. POLYM. COMPOS., 38:1031–1042, 2017. © 2015 Society of Plastics Engineers     

Simultaneous enhancement of dielectric and mechanical properties of high‐density polyethylene/nitrile rubber/multiwalled carbon nanotube composites prepared by dynamic vulcanization

Polymer dielectric composites, which possess high dielectric and loss suppression with excellent mechanical properties, are of crucial importance in practical applications. Herein, high‐density polyethylene/nitrile rubber/multiwalled carbon nanotube (HDPE/NBR/MWCNT) composites were fabricated by the dynamic vulcanization (DV) technique. The effect of DV on the structure and properties of HDPE/NBR/MWCNTs was systematically investigated. The results illustrate that the DV technique combines the advantages of the crosslinked phase and melt processability of thermoplastics. With the increase of dicumyl peroxide content, the dielectric permittivity and the mechanical properties clearly increase, due to a better compatibility and dispersibility achieved by DV. More importantly, a continuous decrease of dielectric loss and conductivity are observed with the increase of dicumyl peroxide content. These can probably be assigned to the combination of better dispersion and slower chain mobility of the NBR phase induced by crosslinking. © 2020 Society of Industrial Chemistry     

Increasing the thermal conductivity of palmitic acid by the addition of carbon nanotubes

Four different methods, acid oxidation, mechanochemical reaction, ball milling, and grafting following acid oxidation, were used to treat multi-walled carbon nanotubes (MWCNTs). During treatment, hydroxyl groups, carboxylic groups, and amidocyanogen were introduced onto the surfaces of the MWCNTs. The MWCNTs were dispersed into palmitic acid (PA) to prepare phase change composites with high thermal conductivity. Both chemical treatment and ball milling help to break the MWCNT aggregates and to enhance their dispersibility. Measurements show that the thermal conductivity increase of the composites is highly dependent on the MWCNT pretreatment process. We propose that the difference in the interfacial thermal resistance between the MWCNTs and the matrix is due to the difference of the MWCNT surface state caused by different treatment processes. In all the MWCNT/PA composites, the one containing MWCNTs with hydroxyl groups, treated by a mechanochemical reaction, has the highest thermal conductivity increase, which, at room temperature, is up to 51.6% for a MWCNT addition of 1.0%.