氯化聚乙烯橡胶/废旧三元乙丙橡胶胶粉共混发泡材料的研究

研究氯化聚乙烯橡胶(CM)/废旧三元乙丙橡胶(EPDM)胶粉共混发泡材料的性能,并采用活化剂420等对废旧EPDM胶粉进行活化改性,考察废旧EPDM胶粉改性对共混发泡材料的影响。结果表明:随着废旧EPDM胶粉用量的增大,共混发泡材料的门尼粘度增大,邵尔C型硬度减小,发泡倍率先增大后减小,发泡收缩率减小;废旧EPDM胶粉改性后,共混发泡材料的门尼粘度变化不大,M_H-M_L值增大,发泡倍率略有减小,但物理性能和发泡收缩率改善,且泡孔结构更密实、更完整。     

发泡剂和废旧胶粉用量对EPDM发泡性能的影响

采用模压化学发泡法制备了EPDM/胶粉共混发泡材料。利用均匀实验设计法设计了实验,研究了废旧胶粉和化学发泡剂用量对EPDM发泡材料硫化特性、力学性能的影响,并通过神经网络和遗传算法对实验数据进行处理。结果表明,随着胶粉用量的增加,发泡材料的交联作用和发泡进程均有所减弱,当胶粉用量在20份以下,发泡剂用量在9~12份时,发泡材料的综合性能较好。     

纤维和粉煤灰对改性橡胶粉水泥基复合材料性能的影响

采用不同的方法对废旧橡胶粉进行表面改性,将其按适宜比例掺入水泥砂浆,复掺一定量粉煤灰,并采用纤维进行增强,制备了性能优异的水泥基复合材料,探讨了界面改性剂在砂浆中的作用机理,分析了废胶粉改性工艺及废胶粉、粉煤灰和纤维掺量对砂浆性能的影响,提出了一种经橡胶、纤维和粉煤灰改性的水泥基复合材料的理论结构模型.结果表明,对废旧橡胶颗粒进行表面改性后,可以在一定程度上提高砂浆的力学性能,纤维、废胶粉及粉煤灰的复合作用使得砂浆的性能有较大地改善,尤其是水泥砂浆的韧性显著增加,干收缩程度减小.     

废胶粉的改性及工业应用

随着废旧橡胶的产量逐年增加,如何有效利用废旧橡胶资源已成为当务之急,胶粉是目前废橡胶的主要回收利用方式之一,但因为胶粉表面活性低,与基体材料的相容性差,在使用时需对其进行改性处理。本文介绍了目前国内外废胶粉的主要改性方法,如再生脱硫改性、机械力化学改性、聚合物涂层改性、接枝或互穿聚合物网络改性、有机-无机杂化等方法,并对胶粉在橡塑、铺装、建筑等领域的应用现状进行了综述。     

废旧轮胎胶粉应力诱导脱硫反应影响因素的研究

在废旧轮胎胶粉/EPDM的熔融挤出过程中,以仲丁醇为脱硫反应促进剂,研究螺杆转速和挤出反应温度对脱硫共混物凝胶质量分数(w)、凝胶分子链结构以及SBR/脱硫共混物再硫化材料物理性能的影响。结果表明:在废旧轮胎胶粉/EPDM的熔融挤出过程中,随着螺杆转速和挤出反应温度的升高,废旧轮胎胶粉颗粒所受的机械剪切应力作用增强,引起废旧轮胎胶粉中交联网络的断裂、降解或解交联反应,导致脱硫共混物w显著减小以及SBR/脱硫共混物再硫化材料中凝胶粒子尺寸明显减小;添加仲丁醇有利于脱硫反应的进行,并具有抑制交联副反应和保护脱硫产物中双键的作用,使脱硫共混物的w进一步减小;在螺杆转速为1 000 r.min-1、挤出反应温度为240℃的条件下,SBR/脱硫共混物(添加仲丁醇)再硫化材料的拉伸强度和拉断伸长率分别为19.3 MPa和567%。     

基于废旧轮胎胶粉的热塑性弹性体的制备及发泡性能研究

通过沥青改性胶粉及采用相容剂与聚丙烯共混制备了性能优良的热塑性弹性体(TPE)材料,并以超临界流体为发泡剂对其发泡性能进行了研究。实验结果表明,胶粉通过沥青改性后,可以明显地提高TPE的拉断伸长率,并且发泡TPE的泡孔平均直径增大,泡孔密度减少,相对密度减小,但是随着沥青用量的增加,材料的粘度降低,从而出现泡孔破裂和塌陷现象,最后导致泡孔平均直径和泡孔密度减小,相对密度增加。相容剂苯乙烯嵌段共聚物接枝马来酸酐(SEBS-g-MA)可以提TPE的拉断伸长率并改善泡孔结构。温度的升高和饱和压力的增大,都导致了发泡弹性体的泡孔增大,泡孔密度和相对密度减小。     

聚丙烯/废旧轮胎胶粉共混物的微孔发泡研究

采用超临界CO2为发泡剂,通过压力释放法对聚丙烯/废旧轮胎胶粉共混物的发泡性能进行研究。结果表明,加入胶粉严重破坏了聚丙烯均匀的泡孔结构,共混物发泡体具有独特的双孔结构;马来酸酐接枝聚丙烯/废旧轮胎胶粉共混物发泡体具有更加均匀一致的泡孔结构。     

回收高密度聚乙烯/废胶粉共混体系的力学性能研究

探讨了废胶粉（WRP）和回收高密度聚乙烯（RHDPE）共混改性时废胶粉的质量分数、相容剂的种类以及胶粉改性剂对RHDPE／WRP共混体系力学性能的影响。实验结果表明，当废胶粉的质量分数为20％时，体系的综合力学性能最佳。在RHDPE／WRP体系中分别添加EPDM、EVA、EAA时，EVA的增容效果最好，添加5％的EVA能使RHDPE／EVA／WRP体系的冲击强度增加55％。废胶粉经自制表面改性剂ACDI预处理后，其相应的RHDPE／EVA／MWRP体系的拉伸强度和弯曲模量分别增加35％和25％，而对共混物的其它性能影响不大。     

反式-1,4-聚异戊二烯与胶粉共混发泡的性能研究

实验对不同共混比的TPI/胶粉共混胶模压发泡,研究了胶粉的含量及胶粉改性方法对共混胶发泡的硫化特性、物理机械性能以及泡孔结构的影响。结果表明:随着胶粉含量的增加,材料的密度逐渐增大,胶粉用量为10份时,拉伸强度、撕裂强度、扯断伸长率三者有所升高,胶粉用量为20份时又略有下降;然后各物理机械性能值随胶粉用量增加呈递增趋势,胶粉用量为40份时,各值达到峰值。相比未改性及用活化剂450改性胶粉,用Si-69包覆改性的胶粉填充TPI基体发泡材料具有较好的拉伸、撕裂强度,试样的泡孔结构更加完整,无破裂和塌陷,泡孔孔径分布一致,泡孔致密均匀。     

胶粉的改性及其在聚合物和沥青材料中的应用

我国每年产生大量的废旧轮胎,对生态环境造成了严重威胁,对其进行合理的回收利用已成为当务之急,而将废旧轮胎加工成胶粉作为原材料使用是很好的解决方法。文章总结了脱硫再生与表面活化等胶粉改性方法及原理,综述了废轮胎胶粉在橡胶、塑料复合材料以及沥青中的应用。着重介绍了胶粉的种类、粒径与不同增容体系对材料性能的影响,以及各种改性手段对于提升胶粉与基体材料界面相互作用的技术原理。最后,对我国胶粉工业未来的发展方向进行了展望。     

EVA/EPDM/IR/IR共混发泡材料的研制与应用

进行了ＥＶＡ／ＥＰＤＭ／ＩＲ三元共混和ＥＶＡ／ＥＰＤＭ／ＩＲ／ＩＲ四元共混发泡材料的研制,经物性对比表明：共混发泡材料的物性较非共混发泡普遍提高。ＥＰＤＭ的混入可以增加发泡材料的拉伸强度和撕裂强度,同时降低收缩率和永久压缩变形;ＩＲ的混入除具备ＥＰＤＭ的优点外尚对提高发泡材料的柔软度有帮助;ＩＲ的混入仅改善发泡材料二次热压成型制品表面的清晰度。     

氯化聚乙烯/废旧轮胎胶粉共混发泡性能研究

采用模压法进行发泡,以氯化聚乙烯（CM）为基体,研究了胶粉用量、硫化温度、硫化助剂对CM发泡体的泡体性能、泡孔结构的影响。结果表明,CM发泡体随着胶粉用量的增加,发泡密度逐渐增加,泡孔体积及发泡倍率逐渐减少。综合CM发泡体的泡体性能及泡孔结构,当胶粉用量为10份,170℃下硫化7min,使用TCHC作硫化助剂时,可得到发泡效果好,断面均匀分布,泡孔结构明显的CM发泡体。     

Impact modification of polypropylene‐based composites using surface‐coated waste rubber crumbs

Blends of maleated polypropylene (MAPP) with high contents of waste rubber powder, namely ground tire rubber and waste ethylene propylene diene monomer (EPDM) powder, were used as impact modifiers for polypropylene (PP) based composites with different reinforcements (hemp, talc, and milled glass fiber). Adding reinforcements led to increase in modulus (tensile, flexural, and torsion moduli) of PP, while its impact strength decreased noticeably. Impact modification of PP‐based composites was successfully performed via inclusion of MAPP/waste rubber compounds, especially compounds containing waste EPDM powder. Inclusion of such impact modifiers increased impact strength of composites over 80%. The effects of impact modification were more significant for hemp‐ and glass‐filled composites compared to composites containing talc. However, slight decrease in tensile, flexural, and torsion moduli (up to 30%) of the composites was also observed after inclusion of impact modifiers. POLYM. COMPOS., 35:2280–2289, 2014. © 2014 Society of Plastics Engineers     

Rheological properties and foam processibility of precured EPDM

EPDM foam was prepared by dynamically vulcanizing EPDM compound in a HAAKE rheometer firstly, then mixing the partially precured EPDM compound with a blowing agent and a sulfur vulcanizing system on a two roll mill. The compound was extruded through a cold feed extruder, and the extrudate was foamed in a circulating hot air oven. EPDM compound was vulcanized partly in the HAAKE rheometer, the final torque increases with increasing sulfur content. Rheological measurement shows the dynamic storage modulus, the loss modulus, and the complex viscosity of precured EPDM compound increase with increasing sulfur content. Then the partially precured EPDM compound was compounded with a blowing agent and a sulfur vulcanizing systems, Rheometric measurement shows that the rate of vulcanization of partially precured EPDM compound is not affected by the precure. The blowing results show that the foam processibility could be improved and the expansion ratio increases in the same processing condition for optimum partially precured EPDM compound, which indicates the optimum crosslink density for EPDM could enhance the efficiency of blowing agent AC. SEM shows that the foam articles have a closed‐cell structure with few open cells, and the large cells inlay among the small cells. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3387–3394, 2006     

Oxidation‐grafting surface modification of waste silicone rubber composite insulator powder: Characterizations and properties of EPDM/modified waste powder composites

In order to broaden the applications of waste silicone rubber composite insulator powder (WSP), modified waste powder (WSP‐KH570) was prepared by a two‐step treatment process involving improved surface oxidation approach by using acidic H₂O₂ solution and subsequently grafting of KH570. Fourier transform infrared spectroscopy in the attenuated total reflection mode (FTIR‐ATR) analysis revealed the presence of KH570 on the powder surface. The result was confirmed by thermogravimetric analysis (TGA). Blends of ethylene propylene diene monomer (EPDM) with WSP‐KH570 were prepared. The effects of WSP‐KH570 on mechanical properties and thermal properties of the blends were investigated. The WSP‐KH570 showed an observed improvement in tensile strength and elongation at break of EPDM/WSP‐KH570 blends compared with corresponding compositions of EPDM/WSP blends. The TGA cure showed that EPDM filled with WSP‐KH570 had higher thermal stability at 210–380 °C than EPDM/WSP. Dynamic mechanical analysis indicated EPDM and WSP‐KH570 were better miscible with the blend ratio (90/10). © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45438.     

废胶粉填充改性PP复合材料

采用熔融挤出共混的方法,选用三种废胶粉填充聚丙烯(PP),制备了PP/废胶粉复合材料,研究了废胶粉质量分数对复合材料力学性能的影响.结果表明:废旧三元乙丙橡胶粉可明显提高复合材料冲击强度和拉伸断裂应变,当其质量分数为60%时,简支梁缺口冲击强度可提高33%,拉伸断裂应变增大了26%,有显著的增韧效果:废旧杂胶粉的加入使...     

Aramid fiber reinforced EPDM microcellular foams: Influence of the aramid fiber content on rheological behavior,mechanical properties,thermal properties,and cellular structure

In this paper, aramid fiber (AF)/ethylene-propylene-diene monomer (EPDM) microcellular foams added with different content of AF are prepared by the supercritical foaming method. The effect of the AF content on the rheological behavior, mechanical properties, thermal properties and cellular structure of the AF/EPDM microcellular foams has been systematically studied. The research illustrates that compared with pure EPDM, the AF/EPDM matrix has greater viscosity and modulus, which is conducive to reduce the cell size and increase its density. And the thermal stability of EPDM foams is improved with the addition of aramid fiber. Meanwhile, when the content of AF is added to 1 wt%, the AF/EPDM microcellular foam exhibits a relatively low thermal diffusion coefficient and apparent density with the thermal conductivity to 0.06 W/mK. When the AF is added to 5 wt%, the tensile strength of the AF/EPDM microcellular foam increases to 1.95 MPa, which is improved by 47% compared with that of the pure EPDM foam. Furthermore, when the compressive strain reaches to 50%, the compressive strength of the AF/EPDM microcellular foam is 0.48 MPa, improved by 296% compared with that of the pure EPDM foam.     

EVA/EPDM/IR/IR共混发泡材料的性能研究

研究了乙烯醋酸乙烯酯共聚物（ＥＶＡ）／ＥＰＤＭ／ＩＲ三元共混和ＥＶＡ／ＥＰＤＭ／ＩＲ／ＩＲ四元共混发泡材料的性能。在ＥＶＡ中混入ＥＰＤＭ可使发泡材料的拉伸强度、撕裂强度和粘合强度提高,而收缩率和压缩永久变形降低;在ＥＶＡ中混入ＩＲ除具备混入ＥＰＤＭ同样的优点外,还可提高发泡材料的柔性;ＩＲ的混入可改善发泡材料二次热压成型制品的表面清晰度。     

Mechanical Properties of Silicone Rubber Enhanced Microcellular EPDM Foams Based on Supercritical CO2 Foaming Technology

Microcellular ethylene-propylene-diene monomer (EPDM) foams derived from miniaturizing the cellular structure can improve mechanical properties of traditional EPDM foams. It is a current challenge that microcellular EPDM foams prepared by supercritical CO₂ foaming technology cannot undergo the post-crosslinking process due to the disappearance of cellular structure, which strongly restricts the development of the mechanical properties of EPDM foams. Hence, a scalable and blending route by selecting the silicone rubber (SR) with different crosslinking temperature compared to EPDM is developed to improve mechanical properties of EPDM foams. During the pre-crosslinking process of EPDM, SR forms a complete crosslinking network, which can make up for the strength of EPDM without the post-crosslinking. Meanwhile, the silica can reduce the domain size of SR and enhance the compatibility between EPDM and SR. As expected, the addition of SR improves the storage modulus, viscosity and matrix strength of EPDM, which shows enhanced mechanical properties of EPDM foams. When the foam density is basically the same, the tensile strength and compressive strength of SR/EPDM foam are increased by 461% and 283% respectively compared with that of EPDM foam. Finally, the maximum tensile strength and compressive strength (40% strain) of SR/EPDM foam achieves 3.58 MPa and 0.59 MPa, respectively.     

Design of ethylene-propylene-diene monomer foam and its double-layer composite for improving sound absorption properties via experimental method and theoretical verification

In this work, the ethylene-propylene-diene monomer (EPDM) foam was fabricated via 4-4′-oxobisbenzenesulfonyl hydrazide (OBSH) and phenolic resin (PF) in an effort to prepare the sound-absorbing composite which has excellent sound absorption at the medium and low frequency. For single-layer EPDM foams, cell morphology showed a certain pattern, causing the peak of the sound absorption coefficient move to a higher frequency and the peak value reached a maximum of about 0.75 as the OBSH content increased. In addition, with the foaming temperature increasing, the cell morphology had a different tendency and the peak of the sound absorption coefficient moved first to the higher frequency and then to the lower frequency due to the vulcanization reaction. Compared with the single-layer EPDM foams, the sound absorption curve of the double-layer composite made of the single-layer EPDM foam and pure EPDM sheet with cavities moved to a lower frequency by about 400 Hz. The theoretical calculation method was used to verify the accuracy of the experimental results. This work provided a simple approach to control the sound absorption property of EPDM foamed material and its double-layer composite through from an experimental and theoretical perspective.