用废木粉增强聚乙烯的研究

本研究采用废木粉为填料增强改性高密度聚乙烯。评价了马来酸酐接枝高密度聚乙烯（MAH-g-HDPE）对聚乙烯基木塑复合材料的增客效果,研究了木粉含量对复合材料力学性能和其它性能的影响,详细阐述了木粉的增强作用机理。研究结果表明：MAH-g-HDPE可显著增进憎水性基质和亲水性木粉之间的界面相互作用,明显改进复合材料的力学性能;在使用适当相客剂的情况下,木粉可明显提高聚乙烯的拉伸强度、弯曲强度和弯曲模量,具有良好的增强效果;当木粉含量为60％时,复合材料的拉伸强度、弯曲强度、弯曲模量分别高达38MPa、54MPa和3500MPa,若与纯基质相比,分别提高了43．4％、176％和283％。这些实验结果表明,木粉对聚乙烯具有明显的增强效果。     

热塑性聚氨酯弹性体在改性双基推进剂中的应用

为了改善力学性能,合成了与硝化甘油(NG)、硝化纤维素(NC)具有良好相溶性的新型热塑性聚氨酯弹性体(TPUE),并应用于改性双基推进剂研究中。研究了热塑性聚氨酯弹性体对硝胺改性双基推进剂的能量性能、力学性能、燃烧性能以及工艺性能的影响。结果表明,在改性双基推进剂中引入TPUE,推进剂的工艺性能、力学性能,尤其是低温力学性能明显提高,燃速和爆热会稍有降低。     

剑麻纤维和聚乙烯改性SBS热塑性弹性体的性能研究

简单介绍了苯乙烯类嵌段共聚物(SBS)和剑麻纤维(SF)的概况,通过机械共混法制备了SBS SF PE三元共混材料,并运用正交实验法对主要配方进行了设计,分析了共混材料的力学性能,如拉伸强度,扯断伸长率,永久形变等,确定了共混材料中各组分的最佳配比     

基于ABS/废旧NBR胶粉热塑性弹性体的制备及性能

采用熔融共混法制备了丙烯腈-丁二烯-苯乙烯三元共聚物(ABS)/废旧NBR胶粉(WNBRP)复合体系,以氯化聚乙烯(CPE)为增容剂改善其界面相容性,研究了CPE用量对其力学性能和微观结构的影响。结果表明,CPE可显著改善ABS/WNBRP复合体系的综合性能,且CPE含量为18份时,综合力学性能最佳;基体中CPE的存在,一方面可以增强ABS与WNBRP的界面相容性,另一方面可以提高基体ABS的塑性变形能力;FE-SEM研究表明,与ABS/WNBRP复合体系相比,增容TPE的断面形貌较为平整,界面结合较好,力学性能提升显著。     

Immobilization of Borate Waste Simulate in Cement-Water Extended Polyester Composite Based on Polyethylene Terephthalate Waste 1-Mechanical Properties of the Final Waste Forms

ABSTRACT

This paper discusses the suitability of Ordinary Portland Cement (OPC), water-extended polyester (WEP), based on recycled polyethylene terephthalate (PET), composite for stabilization/solidification (S/S) of borate waste solution originating from the primary coolant circuit of pressurized water reactors (PWRs).

This treatment is a new and attractive economical process that aims at keeping man and his environment healthy through controlling the dispersion of radioactive wastes (i.e., borate waste solution) and the solid plastic waste materials (i.e., PET).

Mechanical integrity of the WEP as well as its polymer composite (PC) with OPC was studied under different experimental conditions. Compressive strength measurements for the final waste forms of PC containing borate waste simulate were also evaluated using various compositions of the PC (e.g., water of hydration, polymer:cement ratio, borate content, etc.)

Based on the data obtained so far, it could be concluded that the candidate PC with the formulation of polymer:cement ratio 3%, water:cement ratio 40%, polymer:water of emulsion 80/20, and containing up to 3% by weight borate waste simulate shows compressive strength values acceptable for different transportation, storage, and disposal processes.     

基于HIPS/废旧SBR胶粉热塑性弹性体的制备及性能

采用熔融共混法,制备高抗冲聚苯乙烯(HIPS)/废旧丁苯胶粉(废旧SBR胶粉)复合体系,通过在基体HIPS中填加芳烃油和苯乙烯-丁二烯-苯乙烯热塑性弹性体(SBS),研究了体系的力学性能及微观相态结构。结果表明,HIPS/废旧SBR胶粉复合体系中填充10份以上的芳烃油,可获得热塑性弹性体(TPE);在HIPS/废旧SBR胶粉/芳烃油体系中加入SBS进行增容,拉断伸长率有较大提高。拉伸断面形貌研究表明,基体中填充芳烃油和SBS,基体无明显塑性变形和撕裂带,断面平坦,体系具有良好的高弹形变回复能力。     

Studies on Linear Low-Density Polyethylene Functionalized by Ultraviolet Irradiation and Its Compatibilization

Summary Some groups containing oxygen such as C-O, C-OH and C=O were introduced onto the molecular chains of linear low-density polyethylene (LLDPE) through ultraviolet irradiation in air. The concentration of these groups containing oxygen increased with increasing irradiation time. After irradiation, the molecular weight of the LLDPE decreased, and its distribution widened. It was found that the gelation occurred after the LLDPE was irradiated for 12 h, and the gel content increased with increasing irradiation time. The crystal shape and space of the crystalline plane for irradiated LLDPE remained. Compared with those of LLDPE, the melt flow index, tensile strength and elongation at break of the irradiated LLDPE decreased, but its hydrophilicity increased and its toughness retained good. The polyamide 66 (PA66)/LLDPE/irradiated LLDPE blends were prepared by blending a small percentage of irradiated LLDPE with PA66. The melting temperature and crystallinity of both the LLDPE and PA66 components in the blends decreased with increasing irradiation time. The compatibility, dispersion and interfacial interaction between PA66 and LLDPE were improved after blending. With the addition of 5% LLDPE irradiated for 36 h, the tensile strength, bending strength and notched impact strength of the blends was enhanced from 48.3 MPa, 64.8 MPa and 30.8 J/m to 57.4 MPa, 71.5 MPa and 101.2 J/m, respectively.     

Effect of Thermoplastic Elastomer on Melt Rheological and Fracture Behavior of Poly(Lactic Acid)

Poly(lactic acid) (PLA) was melt blended with thermoplastic elastomer, maleic anhydride grafted poly[styrene-b-(ethylene-co-butylene)-b-styrene] (SEBS-g-MA) copolymer with varied concentration (10–40?wt%) using twin screw extruder. Dynamic rheological behavior of PLA/SEBS-g-MA blends investigated a transition from liquid-like behavior to solid-like behavior in the composition range of 10–20?wt% of SEBS-g-MA. The capillary rheometer analysis showed enhanced shear viscosity with increase in SEBS-g-MA content. At 10?wt% of SEBS-g-MA, a maximum in the non-essential work of fracture was observed which reflects resistance to crack propagation. Scanning electron microscopy revealed a transition in deformation mechanisms from voids, to fibrillation and cavitation.     

WRP/POE新型热塑性弹性体的制备及性能

采用聚烯烃弹性体(POE)与废旧胶粉(WRP)制备了热塑性弹性体。研究了共混比、胶粉预塑炼处理工艺及白炭黑对POE/WRP力学性能的影响。结果表明,塑炼WRP/POE共混体系具有优良的综合力学性能,当塑炼WRP为30份时,WRP/POE体系的拉伸强度为7.17MPa,拉断伸长率为778%,撕裂强度为63.3kN/m,邵尔A硬度为72度。保持塑炼WRP用量为30份,随着白炭黑用量的增加,共混体系的拉伸强度,硬度逐渐增加,撕裂强度大幅度增加,拉断伸长率降低。白炭黑用量为30份时,WRP/POE/白炭黑的综合力学性能最佳,原材料成本降低。     

新型热塑性聚氨酯弹性体的结构与性能

以聚己二酸乙二醇丙二醇酯(PEPA)、环氧乙烷/四氢呋喃无规共聚醚(PET)、异佛尔酮二异氰酸酯(IPDI)以及二羟甲基丙二酸二乙酯(DBM)为原料采用熔融预聚法合成了侧链含有酯基的热塑性聚氨酯弹性体(TPUE)。用傅立叶变换红外(FTIR)、凝胶渗透色谱(GPC)、差示扫描量热分析(DSC)和拉伸实验对聚氨酯弹性体的结构和性能进行了表征。结果表明,合成的热塑性聚氨酯弹性体具有较高的相对分子质量(Mn8×104),相对较低的软段玻璃化转变温度(Tg-56℃),具有一定的低温力学性能,并且当硬段质量分数为50%～60%时,呈现较好的力学性能(σm18MPa,εb500%)。在改性双基推进剂中引入TPUE,推进剂的低温力学性能明显提高,高温强度稍有降低。     

EPDM/iPB共混型热塑弹性体的制备与性能

通过对比不同共混比的EPDM/iPB共混体系动态硫化与未硫化的力学性能研究发现,动态硫化后的EPDM/iPB体系的性能明显优于未硫化的,当EPDM/iPB的配比为60/40、动态硫化的时间为6min时,综合性能较好;同时,研究了硫化剂和硫化时间等因素对EPDM/iPB力学性能的影响,结果表明:采用DCP/S作为硫化剂、...     

Study on Effect of Incorporation of Gelatin Fiber in Jute Fabrics-Reinforced Linear Low Density Polyethylene Composite

Jute fabrics (50%)-reinforced linear low density polyethylene (LLDPE) composite was prepared by compression molding and mechanical properties were studied. Gelatin fiber (2%–10%) was incorporated into the jute fabrics-based composites and their mechanical properties were investigated and compared with the control composite. It was found that with the increased of gelatin fiber content in the jute fabrics-based composites, the mechanical properties were found to be decreased, but water uptake and degradation properties were increased significantly. The composite containing 10% gelatin fiber lost 30.2% of its weight, 56.4% TS, 41.8% BS, 26% TM and 25.5% BM after 24 weeks in soil medium.     

Effect of Metallocene-Catalyzed Polyethylene on the Physicomechanical Properties of Blends with High-Density Polyethylene or Low-Density Polyethylene

The physicomechanical properties of polymer blend formulations comprising different grades of metallocene-catalyzed linear low-density polyethylenes (mLLDPEs) with high-density polyethylenes (HDPEs) or a low-density polyethylene (LDPE) were investigated. For blends with HDPE, the addition of mLLDPE improves the Izod impact strength and some tensile properties. For blends with LDPE, adding mLLDPE increases the ductility and the percent elongation at break.     

TODI型热塑性聚氨酯弹性体的制备与性能研究

简单介绍了TODI型热塑性聚氨酯弹性体(TPU)的合成工艺、软段种类、硬段含量、R值等对其性能的影响,并与MDI型TPU的动态力学性能作对比.结果表明,使用预聚体法工艺制备的聚ε-己内酯(PCL)型TPU具有良好性能,硬段含量和R值在一定范围内的提高可提高材料的力学性能,与MDI型TPU相比,高温下TODI型TPU储能...     

TPEX材料的制备及性能研究

选取高密度聚乙烯（PE-HD）和耐热聚乙烯（PERT）共混体系进行交联改性得到一种新型的热塑性交联聚乙烯（TPEX）材料,使其即保留PERT的热塑性又因为部分交联提高了其耐热性和抗蠕变性［交联聚乙烯（PEX）］;对TPEX材料进行了拉伸、弯曲、冲击等力学性能的测试;采用定伸热强度和动态热力学分析仪来表征材料的热强度和拉伸蠕变性能。结果表明,当熔体质量流动速率为1~2 g/10 min（21.6 kg）时,其交联度为(2±1) %,TPEX的综合性能较好,可以满足材料加工应用;维卡软化点温度达到126.1 ℃,具有良好的耐热性能; TPEX的定伸热强度大于PERT与PEX,动态热力学分析仪拉伸蠕变测试TPEX与PEX接近,能够满足工程需要。     

Studies on High Density Polyethylene Reinforced with Phosphate Ore Particles: Thermal,Rheological, Mechanical and Morphological Properties

Calcareous phosphate ore can be utilized as a cost-effective alternate to other inorganic fillers for polymer-based composites. In this study, composites of high-density polyethylene and phosphate rock ore particles were prepared by melt blending and injection-molding techniques. The thermomechanical, rheological, and mechanical properties of these composites were studied to investigate the effect of filler loading on their functionality. The reduction in the crystallinity of phosphate ore/high-density polyethylene composites was observed compared to that of the neat high-density polyethylene. The relative crystallinity of the neat high-density polyethylene decreases from 53 to 30% by the addition of 2.5–15 wt% of ore, respectively. Comparison of the linear dynamic viscoelasticity for the neat high-density polyethylene and the ore-filled composites shows t a monotonic increase in both storage modulus and loss modulus with the increasing frequency. The viscoelastic behavior at high frequencies remains unaffected. However, at lower frequencies, both G′ and G″ exhibit diminished frequency dependence. It was also observed that higher filler content decreased the tensile and impact strength, whereas the Young's modulus of the composites increased. The morphological analysis shows relatively weak interaction between the fillers and the matrix because of agglomeration which in turn adversely affects the mechanical properties of the composites.     

Preparation and Assessment of Phase Morphology,Rheological Properties,and Thermal Behavior of Low-Density Polyethylene/Polyhexene-1 Blends

In this work, polyhexene-1 (PH-1) is synthesized by polymerization of hexane-1 with Ziegler–Natta catalyst and melt blended with low-density polyethylene (LDPE). The phase morphology, rheology, crystallization, and thermal behavior of (LDPE)/PH-1 blends are investigated. A good compatibility is observed in the blends up to 10?wt% PH-1 and the most of the droplets in the fractured surface are covered with and buried in the LDPE matrix and at higher percentage the droplet particle size significantly increased. The effect of microstructure of the blends on the flow behavior is studied by small amplitude oscillation rheology. By decreasing the compatibility and increasing the particle size, the Cole–Cole plots are deviated from the semi-circular shape at higher percentages than 10?wt% of PH-1. The change in the crystallization and melting behavior of LDPE in the blends are studied by differential scanning calorimetry and X-ray diffraction (XRD). It is found that by increasing the PH-1 the melting temperature of LDPE decreased from 112.5 to 110.8°C and crystallization temperature increased from 95.2 to 97.7°C which is evident of the nucleation effect. The intensity of (110) peak in XRD test declined as a remake of amorphous part of LDPE and the degree of crystallinity of LDPE decreased from 28 to 22% at 20?wt% PH-1.     

Impact of Filler Functionalisation on the Crystallinity,Thermal Stability and Mechanical Properties of Thermoplastic Elastomer/Carbon Nanotube Nanocomposites

In the present work, the functionalisation of oxidised SWCNTs and MWCNTs is studied. The functionalised fillers are characterised by Raman spectroscopy and TGA. The functionalised fillers are dispersed in a PBT‐PTMO thermoplastic elastomer matrix via in situ polymerisation. The functionalisation causes a fine filler dispersion right at beginning of nanocomposite manufacturing. The fillers act as nucleating agents for crystallisation and evidences for a grafting from PBT at the surface of the functionalised nanotubes are found. An outstanding reinforcement effect by the functionalised CNTs is confirmed by tensile tests.

     

聚乙烯基木塑复合材料吸水率的研究

将配方中部分至全部的聚乙烯(PE)进行接枝改性,然后与木粉和少量润滑剂混合,用挤出成型法制备了木塑复合材料,研究了改性PE和木粉含量对木塑复合材料吸水率的影响。结果表明,配方中改性PE和未改性PE比例一定时,随着木粉含量降低,木塑复合材料的吸水率降低;在木粉含量较高时保持改性PE和未改性PE总含量不变,则随着改性PE替代未改性PE的量增加,木塑复合材料的吸水率降低,当改性PE完全替代未改性PE时,木塑复合材料的吸水率降至5.5 %;木塑复合材料的吸水率越低,其吸水后强度的变化越小。     

Al-BaSO4/PE复合材料与临床材料性能对比

采用熔融共混方法制备了铝酸酯偶联剂改性硫酸钡(Al-BaSO4)/聚乙烯(PE)复合材料。重点研究了AlBaSO4与PE基体之间的界面结合机制,并且对Al-BaSO4/PE复合材料与临床应用复合材料进行了力学性能对比。运用X射线衍射(XRD)、X射线能谱仪(EDS)、扫描电镜(SEM)及万能拉伸试验等测试方法,表征了复合材料的结构、填料分布、形貌及力学性能。结果表明,铝酸酯偶联剂改善了BaSO4与PE的相容性,Al-BaSO4在聚乙烯基体中的分散性较好,Al-BaSO4/PE复合材料的力学性能优于临床应用产品的力学性能。Al-BaSO4/PE复合材料的拉伸强度与临床应用产品相比,提高了10.4%;断裂伸长率与临床应用产品相比,提高了14.2%;弯曲强度与临床应用产品相比提高了16.4%。