废胶粉填充改性RHDPE增容研究

研究了废胶粉的活化处理、不同种类相容剂对回收高密度聚乙烯/废胶粉(RHDPE/WRP)共混体系的增容效果.结果表明,WRP活化处理对提高WRP界面活性有效果.不同相容剂对提升共混体系性能的影响不同,其中添加10份马来酸酐接枝聚乙烯(PE-g-MAH)相容剂对提升RHDPE/活化WRP体系整体性能最有效,可使RHDPE/WRP共混材料的拉伸强度从简单共混物的18.8 MPa提高到22.5 MPa,缺口冲击强度从37.5 kJ/m2提高到60.9 kJ/m2;热变形温度从55.8℃提高到63.6℃.     

PS-g-MAH的制备及其增容PS阻燃复合材料的研究

以聚苯乙烯(PS)为载体,马来酸酐(MAH)为接枝单体,过氧化二异丙苯(DCP)为引发剂,采用熔融接枝法制备了聚苯乙烯接枝马来酸酐共聚物(PS-g-MAH)。考察了MAH用量、DCP用量对PS-g-MAH接枝率的影响。经红外光谱(IR)表征,接枝物为目标产物。将接枝率为3.7%的PS-g-MAH作为PS/膨胀阻燃剂/热塑性弹性体复合材料的增容剂,探讨了增容剂对该复合材料阻燃、力学和加工性能及微观结构的影响。结果表明,当增容剂用量为12份时,冲击强度达到4.89 kJ/m2,比未增容时提高了87.4%,拉伸强度仍可保持在21.3 MPa。在力学性能得到改善的同时,复合材料的垂直燃烧可达到FV-0级,氧指数由27.1%提高到了27.9%,熔体质量流动速率为4.62g/10min。     

聚乙烯／废轮胎胶粉共混体系力学性能的研究

利用废轮胎胶粉(WTRP)填充改性聚乙烯(PE),研究了 PE/WTRP 共混体系的力学性能。结果表明,采用简单共混方法,加入 WTRP 使共混体系的拉伸强度和缺口冲击强度均明显下降;对 WTRP 表面进行合适程度的活化,添加0.1份(质量份数,下同)过氧化二异丙苯使共混体系界面间形成微交联结构,添加5份增容剂硅烷偶联剂A171接枝高密度聚乙烯对体系进行改性后能明显提高共混体系的力学性能。共混体系的拉伸强度从简单共混物的14.4 MPa 上升至20.7 MPa,缺口冲击强度从14.8 kJ/m~2上升至39.6 kJ/m~2;通过测定胶粉的凝胶含量表征了胶粉的表面相对活化度。     

环氧基硅烷改性氰酸酯树脂的性能研究

采用环氧基硅烷(ESi)对双酚A型二氰酸酯树脂(BCE)进行改性,研究了ESi用量对ESi/BCE体系力学性能和动态力学性能等影响。结果表明:适量的ESi可以明显提高BCE的韧性和强度;当w(ESi)=6%时,ESi/BCE改性体系的力学性能最好,其冲击强度和弯曲强度分别从10.1 kJ/m2、94.11 MPa提高到14.49 kJ/m2、110.94 MPa;ESi/BCE体系的交联密度降至适度是其韧性提高的主要原因,并且其玻璃化转变温度(Tg)低于纯BCE体系(但降幅不大)。     

分子筛负载马来酸酐及改性PP的研究

通过物理吸附将马来酸酐(MAH)负载在分子筛上,经母料法熔融制备了PP/分子筛复合材料.采用DSC、POM和电子拉力机等方法对复合材料的结晶行为和力学性能进行研究.结果表明:分子筛对PP结晶起到异相成核作用,随分子筛用量增加,复合材料的结晶温度由纯PP的116.3℃提高到119.5℃,结晶热焓逐渐减小,熔融热焓逐渐增大,复合材料的拉伸强度、弯曲强度及弯曲模量有不同程度的提高.低MAH负载量的分子筛(质量分数3%)有助复合材料力学性能的进一步提高,复合材料的拉伸强度、弯曲强度、弯曲模量及冲击强度分别由纯PP的35.3 MPa、45.2 MPa、1.47 GPa及2.24 kJ/m2提高到37.6 MPa、53.5 MPa、1.85 GPa及3.01 kJ/m2.MAH具有诱导PP形成β晶的倾向,150℃附近的β晶熔融峰强度随MAH用量增加而提高.     

PA6/POE共混体系的性能研究

利用双螺杆挤出机将尼龙(PA)6与聚烯烃弹性体(POE)共混,研究添加过氧化二异丙苯(DCP)、马来酸酐(MAH)后的体系性能以及工艺条件对性能的影响。结果表明,POE含量在15份时缺口冲击强度仅提高了3 k J/m2,拉伸强度降低明显;当双螺杆挤出机的转速为100 r/min,DCP用量为0.2份,体系的力学性能达到最佳值;在DCP用量为0.2份时,添加0.4份MAH,体系的缺口冲击强度相对于纯PA6,提高约12 k J/m2;通过SEM分析冲击断面发现,加入了DCP或DCP/MAH后,POE分散相尺寸相对于单纯的两相共混体系的明显减小。     

反应增容聚丙烯/废胶粉共混物的研究

按一定的次序将单体二乙烯基苯(DVB)、马来酸酐(MAH)、引发剂过氧化二异丙苯(DCP)与聚丙烯(PP)及废胶粉(WRP)等在高速混合机中混合均匀后.在双螺杆挤出机中就地反应增容制备PP/WRP共混材料,讨论了DVB/MAH/DCP的用量对PP/WRP共混物的拉伸强度、缺口冲击强度以及弯曲强度的影响.通过扫描电镜(SEM)分析了反应增容对PP/WRP共混物界面的影响.结果表明,双单体反应增容能有效抑制PP降解,改善共混物界面相容性.提高共混物的力学性能.当引发剂和双单体的质量分数分别为0.2%和3.0%,DVB/MAH的质量比为3～4时,PP/WRP共混物的综合性能最佳.     

mPE-g-MAH对HDPE/木粉复合材料的改性

采用废木粉填充高密度聚乙烯（HDPE）制备木塑复合材料。采用马来酸酐接枝茂金属聚乙烯（mPE—g-MAH）对复合材料进行增容和增韧，并阐述了它的增容和增韧机理。讨论了mPE—g—MAH用量对复合材料的力学性能如拉伸强度、冲击强度、弯曲强度、弯曲模量的影响。结果表明，mPE—g—MAH不仅可明显提高复合材料的强度和韧性，而且也使材料的弯曲模量有了一定的提高。当其质量分数为16％时，复合材料的拉伸强度、冲击强度分别由原来的16．2MPa和4．5kJ／m^2提高到30．5MPa和9．8kJ／m^2。     

MAH原位接枝HDPE及其对HDPE/N-PCB复合材料力学性能的影响

将马来酸酐(MAH)、过氧化二异丙苯(DCP)、苯乙烯(St)、高密度聚乙烯(HDPE)和废印刷电路板非金属粉末(N-PCB)直接反应挤出,制备了HDPE/N-PCB复合材料,并研究了MAH用量对HDPE/N-PCB复合材料力学性能影响。对HDPE/N-PCB复合材料抽提残留物的红外分析结果表明,在HDPE/N-PCB复合材料中加入DCP、St、MAH之后,通过DCP引发HDPE原位接枝MAH,并随即与N-PCB粉末表面的羟基反应而起到了桥联作用,可改善HDPE基体与N-PCB粉末两相的界面作用。MAH反应增容后的HDPE/N-PCB复合材料与增容前相比,其拉伸强度、弯曲强度、缺口冲击强度及断裂伸长率的最大增幅分别为36%、12%、208%和262%。     

多单体反应挤出PP/胶粉共混材料的研究

按一定的次序将单体马来酸酐(MAH)、苯乙烯(St)、引发剂过氧化二异丙苯(DCP)、聚丙烯(PP)、废胶粉等在高速混合机中混合均匀后,在双螺杆挤出机中就地反应增容制备 PP/胶粉共混材料。讨论了 MAh/St/DCP 三者的含量对 PP/胶粉共混材料力学性能的影响;红外光谱(FTIR)分析证明双单体成功接枝于 PP 大分子链中。通过扫描电镜分析了一步法反应增容对 PP/胶粉共混物界面的影响。结果表明,一步法反应增容改善了共混物的界面相容性,当 PP、胶粉、DCP、MAH、St 的配比为70/30/0.1/1.5/1.5时,PP/胶粉共混物的拉伸强度和悬臂梁缺口冲击强度达到最佳。     

Facile fabrication of shape memory composites from natural Eucommia rubber and high density polyethylene

Shape memory materials are a type of smart material with potential applications in sensors, textiles, aerospace engineering and medical devices. In this study, we prepared Eucommia rubber and high density polyethylene (HDPE) composites with co‐continuous architecture by a simple physical blending method. The shape memory composites memorized two temporary shapes using different melting points of natural Eucommia rubber and HDPE with the addition of dicumyl peroxide (DCP). The architecture of Eucommia rubber/HDPE composites is critical to the materials' properties: each component forms a three‐dimensional percolating network and good properties of the two components may be synergically combined. Our results showed that the memory behavior of the composites was dependent on the degree of crystallinity in the composites. When the DCP was 1 phr, the physical and mechanical properties of the Eucommia rubber/HDPE composites improved and exhibited excellent shape memory behavior, with better values of the shape fixity ratio than of the shape recovery ratio. When DCP was 6 phr, the crystalline phase of Eucommia rubber in the composites was almost completely destroyed, which resulted in one temporary shape memory behavior of the composites. © 2016 Society of Chemical Industry     

Effect of dicumyl peroxide and phenolic resin as a mixed curing system on the mechanical properties and morphology of TPVs based on HDPE/ground tire rubber

Thermoplastic vulcanizates (TPVs) are a special group of thermoplastic elastomer with the characteristic that consists of rubber elasticity and the processability of thermoplastic polymers. TPVs based on high density polyethylene (HDPE)/ground tire rubber (GTR) with phenolic resin (HY‐2045) and dicumyl peroxide (DCP) as vulcanizing agents are prepared through dynamic vulcanization in this article. The blends consisting of 40/60 HDPE/GTR are melt‐mixed in an internal mixer and then pressed with a compression molding machine. The aim of this experiment is to study the influence of a compound curing agent system on the mechanical properties of the HDPE/GTR composites. The results indicate that the mechanical properties of the HDPE/GTR blends are improved significantly by adding 4 phr HY‐2045 and 0.3 phr DCP than those of TPVs without any vulcanizing agents after dynamic vulcanization. The X‐ray photoelectron spectroscopy study and the FTIR‐ATR analysis confirmed that the crosslinking phenomenon occurred in the preparation of TPVs; and the gel fraction analysis indicates that the GTR components and the HDPE components of the HDPE/GTR blends are all moderately crosslinked. In addition, the morphology of the HDPE/GTR blends has been investigated by scanning electron microscopy. POLYM. COMPOS., 36:1907–1916, 2015. © 2014 Society of Plastics Engineers     

Thermoplastic elastomers based on high‐density polyethylene,ethylene–propylene–diene terpolymer,and ground tire rubber dynamically vulcanized with dicumyl peroxide

Thermoplastic vulcanizates (TPVs) based on high‐density polyethylene (HDPE), ethylene–propylene–diene terpolymer (EPDM), and ground tire rubber (GTR) were dynamically vulcanized with dicumyl peroxide (DCP). The polymer blend was composed of 40% HDPE, 30% EPDM, and 30% GTR, and the concentration of DCP was varied from 0.3 to 3.6 parts per hundred rubber (phr). The properties of the TPVs were determined by evaluation of the gel fraction content and the mechanical properties. In addition, IR spectroscopy and differential scanning calorimetry analysis were performed as a function of the DCP content. Decreases in the Young's modulus of the blends and the crystallinity of HDPE were observed when the content of DCP was greater than 1.8 phr. The results regarding the gel content indicate that the presence of DCP promoted the crosslinking of the thermoplastic matrix, and optimal properties were obtained with 1.5% DCP. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39901.     

Preparation and characterization of environment friendly used rubber powder modified pulp sediments composites

In recent years, with growing contradiction between energy supply and demand, the more and more high demand of the environmental protection is needed. The work represented an environment friendly method for recycling of waste rubber and pulp sediment that a new composite material was prepared using pulp sediment as the matrix, used rubber powder as the toughening agent, and sawdust as the reinforcement. The effects of used rubber powder content on the mechanical properties of the pulp sediment and sawdust/pulp sediment were studied by measuring Shore A hardness, tensile stress, and elongation-at-break. The morphology of used rubber powder/pulp sediment composites was analyzed by scanning electronic microscopy and transmission electron microscopy. The curing conditions were also discussed. The results showed when the used rubber powder/pulp sediment mass ratio was 8/100, the used rubber powder/pulp sediment sample showed smooth surface, high hardness, compact structure, uniform arrangement, and good compatibility. When the pulp sediment used as the matrix, sawdust as the reinforcement, and used rubber powder as the toughening agent, the proper recipe of the composites was 100?phr pulp sediment, 30?phr sawdust, and 10?phr used rubber powder. The mechanical properties of the used rubber powder/pulp sediment were greater than those of pure pulp sediment and used rubber powder/sawdust/pulp sediment. The best curing conditions for the used rubber powder/pulp sediment composites were at 150?°C under 5?MPa for 15?min. The study on used rubber powder modified pulp sediment, exploits a new way to recycle used rubber powder and pulp sediment, not only benefit environment purification, but also reduce cost of sheet materials, and develops a new way for the economy and environment protection.     

Mechanical and dynamic mechanical properties of waste rubber powder/HDPE composite

Mechanical and dynamic mechanical properties of a waste rubber powder‐filled high‐density polyethylene (HDPE) composite are investigated. Rubber powder is surface‐modified with acrylamide (AAm) using ultraviolet. Rubber powder and HDPE are extruded using a single‐screw extruder and maleic anhydride‐grafted polypropylene is added as a compatibilizer to improve the adhesion between rubber powder and HDPE. The tensile stress and strain of AAm‐grafted rubber powder/compatibilizer/HDPE composites always exhibit higher values than those of unmodified rubber powder/HDPE composites. Surface modification of rubber powder is shown to decrease the magnitude of the tan δ of the HDPE composite. Higher values of the notched Izod impact strength of a surface‐modified rubber‐filled composite is observed compared to those of unmodified rubber‐filled composite. Experimental results show that acryl amide‐grafted rubber powder reacts with maleic anhydride and it results in improved mechanical properties of the HDPE composite. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2595–2602, 2000     

Mechanical properties of high‐density polyethylene/scrap rubber powder composites modified with ethylene–propylene–diene terpolymer,dicumyl peroxide,and silicone oil

The effect of ethylene–propylene–diene terpolymer (EPDM), dicumyl peroxide (DCP), and dimethyl silicone oil on the mechanical properties of high‐density polyethylene (HDPE) composites filled with 60 mesh cryogenically scrap rubber powder (SRP) was studied. The addition of 10 wt % EPDM, 0.2 wt % DCP, and 4 wt % dimethyl silicone oil significantly increased both the impact strength and elongation at break of the HDPE/SRP composites. After the modification, the impact strength increased by 160%, and the elongation at break increased by 150% for the composites containing 40 wt % SRP. The impact load–time curves showed that the increase of impact energy for the modified composites was attributed to the increase of the maximum force at yield point and the ductile deformation after yielding. The rheological behavior, dynamic mechanical properties, and morphology observation suggested that an enhanced adhesion between SRP and polymer matrix formed in the modified HDPE/SRP composites. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2020–2027, 2003     

聚醚型聚氨酯混炼胶性能研究

研究了炭黑补强剂和过氧化物（DCP,BIPB）对混炼型聚醚聚氨酯橡胶力学性能的影响,讨论了DCP和补强剂用量变化以及热空气老化对性能的影响。结果表明,DCP硫化胶拉断伸长率高,BIPB硫化胶永久变形低;当DCP用量为1.6份时,拉伸强度和撕裂强度最高,分别为25.3MPa和47.5kN/m;随补强剂用量的增加,混炼橡胶硬度增加,拉伸强度变化不明显,拉伸永久变形变大。     

CM和HDPE对再生橡胶物理机械性能的影响

研究CM和HDPE对再生橡胶物理机械性能的影响。结果表明,再生橡胶的门尼粘度随着CM用量的增加而降低,随着HDPE用量的增加而增加。再生橡胶的拉伸强度和拉断伸长率随着CM和HDPE用量的增加逐渐增加;扫描电镜研究表明,添加CM的再生橡胶硫化胶的拉伸断面相对平整,断层更均匀。综合比较当CM用量为8phr时,再生橡胶的综合性能最佳。     

Effect of KH550 on the Preparation and Compatibility of Carbon Fibers Reinforced Silicone Rubber Composites

Silicone rubber has good heat resistance, but its mechanical properties are poor. To improve the mechanical properties of the silicone rubber, the carbon fiber / silicone rubber composites were prepared in this paper, in which the silicone rubber was used as the matrix, the high-performance carbon fiber (CF) treated with coupling agent is used as the reinforcement. The best composite formulation, the types and content of coupling agent are determined by testing mechanical properties of the composites. The morphology structures of the composites were observed by scanning electron microscope (SEM), the compatibility between carbon fiber and silicone rubber was studied by infrared spectrum analysis (IR), dynamic thermal mechanical analysis (DMA) and X-ray photoelectron spectroscopy (XPS). The results show that the best composite formulation is silicone rubber of 100 phr, carbon fiber of 12 phr, coupling agent KH550 of 2.5 phr. The best first curing conditions are at 175 ^°C under 10 MPa for 30 min, the postcuring conditions are at 200 ^°C for 2h. The compatibility between carbon fiber treated with KH550 and silicon rubber is the best by SEM, IR, DMA and XPS analysis, and confirm that the coupling agent KH550 plays a compatilizer role in the preparation process of the carbon fiber/silicone rubber composites.