Nonisothermal crystallization of poly(phenylene sulfide) in presence of molten state of crystalline polyamide 6

The nonisothermal crystallization and melting behavior of a poly(phenylene sulfide) (PPS) blend with polyamide 6 (PA6) were investigated by differential scanning calorimetry. The results indicate that the crystallization parameters for PPS become modified to a greater extent than those for PA6 in the blends. The PPS and PA6 crystallize at high temperature as a result of blending. The crystallization temperatures of PPS in its blends are always higher than that of pure PPS and are independent of the melting temperature and the residence time at that temperature. The PPS crystallization peak becomes narrower and the crystallization temperature shifts to a higher temperature, suggesting a faster rate of crystallization as a result of blending with PA6. This enhancement in the nucleation of PPS could be attributed to the possible presence of interfacial interactions between the component polymers to induce heterogeneous nucleation. On the other hand, the increase in the crystallization temperature of PA6 can be attributed to the heterogeneous nucleation provided by the already crystallized PPS. The heterogeneous nucleation induced by interfacial interactions depends on the temperature at which the polymers remain in the molten state and on the storage time at this temperature. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 3033–3039, 1999     

Physical properties of polyamide 6/metallocene isotactic polypropylene conjugated filaments

Polyamide 6 (PA 6) and metallocene isotactic polypropylene (m‐iPP) polymers were extruded (in proportions of 75/25, 50/50, and 25/75) from two melt twin‐screw extruders to prepare three PA 6/m‐iPP conjugated filaments. This study investigated the physical properties of PA 6/m‐iPP conjugated filaments with gel permeation chromatography, differential scanning calorimetry, thermogravimetric analysis, potentiometry, rheometry, density‐gradient measurements, wide‐angle X‐ray diffraction, extension stress–strain measurements, and scanning electron microscopy. The flow behavior of PA 6/m‐iPP polyblended polymers exhibited negative‐deviation blends, and a 50/50 PA 6/m‐iPP blend showed the minimum value of the melt viscosity. The experimental results from differential scanning calorimetry indicated that PA 6 and m‐iPP molecules formed an immiscible system. The tenacity of the PA 6/m‐iPP conjugated filaments decreased initially and then increased as the m‐iPP content increased. The crystallinities and densities of the PA 6/m‐iPP conjugated filaments had a linear relationship with the blend ratio. Morphological observations revealed that the blends had a dispersed‐phase structure. A pore/fiber morphology of a larger size (from 0.5 to 3 μm in diameter) was observed after a formic acid (PA 6 was moved)/xylene (m‐iPP was moved) treatment on the cross section of a PA 6/m‐iPP conjugated filament. PA 6 and m‐iPP polymers were proved to be an incompatible system. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1471–1476, 2006     

Multiple melting behavior of polyphenylene sulfide blends with polyamide 6

Although there are many studies on the multiple melting behavior of polyphenylene sulfide (PPS) homopolymer, similar investigations on PPS component in PPS blends with thermoplastics are relatively rare. In the present paper, the multiple melting behavior of PPS blends with polyamide 6 (PA6) have been investigated by differential scanning calorimetry (DSC). The double melting peaks are also observed for PPS in the blends. Although the annealing temperature and time as well as the heating rate of DSC scanning are different, the lower melting peak temperature of PPS in the blend is higher than that of pure PPS and the higher melting peak temperature is lower than that of pure PPS. It is suggested that PA6 can accelerate the cold‐crystallization of amorphous PPS due to the possible presence of interfacial interaction between the component polymers to induce the heterogeneous nucleation, and increase the perfection of PPS crystals. The multiple melting behavior of PPS in the blends are explained by recrystallization. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1579–1585, 2000     

Interfacial Characterization of Epoxy-bonded Maraging Steel

Adhesion phenomena involving polymer-metal interfaces have become a central subject for research and technological development, especially in view of adhesive bonding of metallic components in primary load-bearing structures. Since adhesion implies that some sort of chemical and/or physical interactions take place between the metal adherend and the polymeric adhesive, a great deal of attention has been devoted to identification and characterization of such interactions and to the development of techniques to study them. Among the most widely used methods for interfacial studies are: ESCA (Electron Spectroscopy for Chemical Analysis), AES (Auger Electron Spectroscopy), SIMS (Secondary Ion Mass Spectroscopy), IR spectroscopy, optical microscopy, and electron microscopy.     

Interfacial Characterization of Epoxy-bonded Maraging Steel

Adhesion phenomena involving polymer-metal interfaces have become a central subject for research and technological development, especially in view of adhesive bonding of metallic components in primary load-bearing structures. Since adhesion implies that some sort of chemical and/or physical interactions take place between the metal adherend and the polymeric adhesive, a great deal of attention has been devoted to identification and characterization of such interactions and to the development of techniques to study them. Among the most widely used methods for interfacial studies are: ESCA (Electron Spectroscopy for Chemical Analysis), AES (Auger Electron Spectroscopy), SIMS (Secondary Ion Mass Spectroscopy), IR spectroscopy, optical microscopy, and electron microscopy.     

Role of acid-base interfacial bonding in adhesion

The strength of macroscopic adhesive bonds of polymers is known to be directly proportional to the microscopic exothermic interfacial energy changes of bond formation, as measured by Dupre's 'work of adhesion'. Since the work of adhesion can be very appreciably increased by interfacial acid-base bonding with concomitant increases in adhesive bond strength, it is important to understand the acid-base character of polymers and of the surface sites of substrates or of the reinforcing fillers of polymer composites. The best known acid-base bonds are the hydrogen bonds; these are typical of acid-base bonds, with interaction energies dependent on the acidity of the hydrogen donor and on the basicity of the hydrogen acceptor. The strengths of the acidic or basic sites of polymers and of inorganic substrates can be easily determined by spectroscopic or calorimetric methods, and from this information one can start to predict the strengths of adhesive bonds. An important application of the new knowledge of interfacial acid-base bonding is the predictable enhancement of interfacial bonding accomplished by surface modification of inorganic surfaces to enhance the interfacial acid-base interactions.     

金属基复合材料的摩擦学性能及结合强度试验研究

以聚酰胺66（PA66）、聚苯硫醚(PPS) 及65Mn钢板为主要原料,制备了一系列不同配比的金属基复合材料,并对这些材料进行不同条件下的摩擦学性能试验,最后通过结合强度试验来分析材料间的结合强度。结果表明,复合材料的摩擦因数及磨损速率随着聚酰胺66的增加而降低;同种材料的摩擦系数及磨损速率随着载荷和对摩速度的增加而先增大后减小;结合强度试验表明金属基复合材料的结合强度随着聚苯硫醚的增加而逐渐增大。     

大分子键合处理氢氧化铝的表面性质及其与常用聚合物的界面特性

本文研究了经大分子以键合方式包覆处理的氢氧化铝粉末的表面性质以及其与常用聚合物的界面特性。结果表明：（１）与末处理过的氢氧化铝相比,非极性液体与处理过的氢氧化铝压片的接触角变化较小,而极性液体与它的接触角一般明显增大。（２）改性后的氢氧化铝的表面张力均明显下降,其中表面张力有极性分量大幅度下降而色散分量稍有提高。与常见聚合物的界面张力以及它的极性分量和色散分量均降而色散分量稍有提高。与常见聚合物的     

β‐Nucleation of pimelic acid supported on metal oxides in isotactic polypropylene

To investigate the nucleation of metal pimelate for isotactic polypropylene (iPP) crystallization, iPP filled with a series of metal oxides with and without metal pimelate on their surface was prepared. There was a chemical reaction between pimelic acid (PA) and metal oxides MgO, CaO, BaO or ZnO, but not TiO₂. The corresponding metal pimelate formed by the chemical reaction between PA and MgO, CaO, BaO or ZnO had a different influence on the crystallization behavior and melting characteristics of iPP. Addition of metal oxides increased the crystallization temperature of iPP and mainly formed α‐phase due to the heterogeneous α‐nucleation of metal oxides. The α‐nucleation of CaO could be easily changed into β‐nucleation using CaO‐supported PA, and 90.1% β‐phase was obtained. The β‐nucleation of BaO could be markedly enhanced by barium pimelate formed using supported PA. However, no β‐phase was observed for iPP filled with MgO‐ or ZnO‐supported PA. The various metal oxides with supported PA had a different influence on the crystallization behavior and melting characteristics of iPP due to the different structure of metal pimelate formed by chemical reaction between PA and the metal oxides. Copyright © 2012 Society of Chemical Industry     

Effect of hybrid polysphosphazene coating treatment on carbon fibers on the interfacial properties of CF/PA6 composites

Carbon fiber (CF) reinforced polyamide 6 (PA6) composite has an extensive application. However, the performances of CF/PA6 composite are constrained by the poor interfacial adhesion between CF and PA6 matrix. In this article, in order to strengthen the interfacial adhesion of CF/PA6 composite, a layer of poly(cyclotriphosphazene-co-4,4′-sulfonyldiphonel) (PZS) hybrid coating with plenty of PZS microspheres (PZSMS) was successfully introduced onto CF surface through facile in situ polymerization. After surface modification, the surface morphologies and the surface chemical structures of fibers changed distinctly. On one hand, the PZSMS provided more contact points and increased mechanical interlocking between CF and PA6 matrix. On the other hand, numerous hydrogen bonds between CF and PA6 were formed due to a great amount of unique polar groups on modified CF surface. Consequently, in comparison with untreated CF, the interfacial shear strength of CF-PZSMS/PA6 composites was improved from 37.68 ± 3.16 to 53.79 ± 3.38 MPa, by 42.75 ± 3.02%. The results indicated that PZS hybrid coating on fiber surface effectively improved the interfacial adhesion of CF/PA6 composites, and the stronger hydrogen bonding and the enhanced mechanical interlocking synergistically played a major role in such significant improvements.     

Processing of single polymer composites using the concept of constrained fibers

The concept of “overheating” is one of the known methods for manufacturing single polymer composites. This concept is validated on two categories of semi‐crystalline polymers: the drawable, apolar (i.e., isotactic polypropylene [iPP], ultra‐high molecular weight polyethylene [UHMWPE]) and the less drawable, polar ones (i.e., polyethyleneterephalate [PET] and polyamides [PA]). The interchain interactions in apolar polymers are relatively weak and therefore a high degree of drawability can be obtained. Polar polymers on the other hand have relative strong interchain interactions, they are therefore less drawable. A shift higher than 20°C of the melting temperature can be obtained in case of highly extended iPP (draw ratios >14). Ultra‐drawn PE shows only 10°C overheating upon constraining and this is mainly due to the change in chain mobility for PE in the hexagonal phase. In case of PET and PA6, only draw ratios of 4 could be reached; however, temperature shifts of about 10°C for constrained fibers compared to unconstrained fibers could be measured. A proof of principle of the potential of the constraining concept for the manufacturing of single polymer composites is obtained by the preparation of single fiber model composites. The effect of the post‐drawing conditions on overheating is examined in details on the example of iPP. It is concluded that both post‐drawing temperature and ultimate draw ratio have a significant influence on the degree of overheating. POLYM. COMPOS., 26:114–120, 2005. © 2004 Society of Plastics Engineers     

Industrial waste origin succinic anhydride‐grafted atactic polypropylene as compatibilizer of full range polypropylene/polyamide 6 blends as revealed by dynamic mechanical analysis at the polypropylene glass transition

This work deals with a dynamic mechanical analysis (DMA) study on the effect of a novel interfacial agent containing maleated grafts on an industrial waste origin atactic polypropylene. This contains 3% of bridge‐, backbone‐, and terminal‐grafted succinic anhydride groups (aPP‐SA/SA). By considering a polymer blend as a special case of composite where the dispersed phase is mobile, it is assumed that both the amounts of polyamide 6 (PA6) and the interfacial agent (aPP‐SA/SA) cause changes in the glass transition temperature of the polypropylene phase in the blend. In this work, we have used DMA parameters to evidence the real interfacial modifications caused by the presence of aPP‐SA/SA in the isotactic polypropylene (iPP)/PA6 system at the iPP glass transition temperature on the basis that this is an unfavorable scenario for the action of aPP‐SA/SA. Since each component of the blend is interacting with each other, and to include the influence of the dispersed phase, it is possible to use a Box–Wilson experimental design model by resembling the so‐called “agent based models” to obtain algorithms forecasting the dynamic mechanical parameters (storage, E’, and loss moduli, E”) at the glass transition of iPP, in all the composition range of whatever iPP/PA6/aPP‐SA/SA‐modified blend. POLYM. ENG. SCI., 59:2458–2466, 2019. © 2019 Society of Plastics Engineers     

Experimental and numerical investigation on the strength of polymer-metal hybrid with laser assisted metal surface treatment

The aim of this study was to evaluate the effect of laser assisted treating metal surface on the strength of polymer-metal hybrid. The oxide film on the metal surface was removed by caustic soda and nitric acid solution. After that, the metal surface was treated by fiber laser, and the hot pressing connection between polymer and metal was completed by plate vulcanizing machine. And then, the tensile strength was obtained by using universal testing machine. The effect of different laser power, different scanning line width and different scanning speed on the bonding strength of polymer-metal hybrid was investigated. The correlation between the characteristics of metal surface and the bonding strength of polymer-metal hybrid was analyzed based on the micro structure morphology and scanning electron microscope (SEM). The results show that the bonding strength of polymer-metal hybrid increases first and then decreases with the increase of laser power. With the increase of scanning line width, the strength of polymer-metal hybrid increases. When the scanning speed is 500?mm/s, the strength of polymer-metal hybrid is the lowest. Based on the experiment, a simplified model is established and analyzed. Through using ABAQUS to conduct the numerical simulations, the results are consistent with the theoretical analysis and experimental data.     

磁控溅射镀膜技术在高分子轻量化材料中的应用

针对聚苯硫醚(PPS)、聚醚醚酮(PEEK)高分子轻量化材料在电子产品应用中面临的表面金属化需求,研究了金属膜层对电磁屏蔽性能的影响特点,结合磁控溅射镀膜特点以及工艺可靠性,表面金属化镀层选择了底层厚度为1μm的Cu、表层厚度为0.3μm的Ni的双镀层结构,并对PPS,PEEK样件表面进行了金属化镀覆处理。结果表明,样件表面的Cu/Ni双镀层结构电磁屏蔽性能与铝合金相当,镀层结合力达到ISO等级1级,环境适应性满足GJB 150A–2009规定的相关要求,达到了PPS,PEEK材料在有电磁屏蔽要求的电子产品中部分替代铝合金的目的。为PPS,PEEK等高分子轻量化材料在应用中面临的表面金属化问题提供了一种新的解决思路。     

Nonisothermal crystallization of polyamide 66/poly(phenylene sulfide) blends

The crystalline morphologies of isothermally and nonisothermally crystallized poly(phenylene sulfide) (PPS) and its blend with polyamide 66 (PA66) were investigated by polarized optical microscopy with a hot stage. The spherulite superstructure of PPS was greatly affected by crystallizable PA66; a Maltese cross was not clear, and the impingement between spherulites disappeared. This could be ascribed to the formation of small crystals of PA66, which filled in the PPS lamellae. The nonisothermal crystallization behavior was also measured by differential scanning calorimetry. The presence of PA66 changed the nonisothermal crystallization process of PPS. The maximum crystallization temperature of the PPS phase in the blend was higher that that of neat PPS, and this indicated that PA66 acted as a nucleus for PPS. Also, the compatibilizer poly(ethylene‐stat‐methacrylate) (EMA) was added to modify the interfacial interplay of the PA66/PPS blend system. The addition of EMA greatly influenced the nonisothermal crystallization process of the PPS phase in the blend system. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Nonisothermal crystallization and melting behavior of β‐nucleated isotactic polypropylene and polyamide 66 blends

A highly novel nano‐CaCO₃ supported β‐nucleating agent was employed to prepare β‐nucleated isotactic polypropylene (iPP) blend with polyamide (PA) 66, β‐nucleated iPP/PA66 blend, as well as its compatibilized version with maleic anhydride grafted PP (PP‐g‐MA), maleic anhydride grafted polyethylene‐octene (POE‐g‐MA), and polyethylene‐vinyl acetate (EVA‐g‐MA), respectively. Nonisothermal crystallization behavior and melting characteristics of β‐nucleated iPP and its blends were investigated by differential scanning calorimeter and wide angle X‐ray diffraction. Experimental results indicated that the crystallization temperature (T) of PP shifts to high temperature in the non‐nucleated PP/PA66 blends because of the α‐nucleating effect of PA66. T of PP and the β‐crystal content (K_β) in β‐nucleated iPP/PA66 blends not only depended on the PA66 content, but also on the compatibilizer type. Addition of PP‐g‐MA and POE‐g‐MA into β‐nucleated iPP/PA66 blends increased the β‐crystal content; however, EVA‐g‐MA is not benefit for the formation of β‐crystal in the compatibilized β‐nucleated iPP/PA66 blend. It can be relative to the different interfacial interactions between PP and compatibilizers. The nonisothermal crystallization kinetics of PP in the blends was evaluated by Mo's method. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

The crystallization and rheological behaviors of in situ microfibrillar isotactic polypropylene/polyamide 66 composites with a selective β-nucleating agent distribution

In situ microfibrillar composites (MFCs) with isotactic polypropylene (iPP) as matrix and β-nucleating agents filled polyamide 66 (β-PA66) as dispersed microfibrils were fabricated through multistage stretching extrusion technology. The simultaneous effects of β-nucleating agents, shear-flow and microfibrils on the crystallization and rheological behaviors of iPP were explored. Crystallization analysis demonstrated that the counteraction of shear flow and β-nucleating agents resulted in the absence of β-crystal in the as-extruded MFCs. When the MFCs were annealed at 210°C for 10 min, the flow field was erased accompanied with the migration of β-nucleating agents from PA66 phase to surface, which in turn inducing the formation of β crystal in the recrystallized samples. Shear rheological investigations suggested that the β-NAs at interface mechanically integrated the PA66 and iPP phase thus improving the interfacial adhesion. These findings provided a potential way to solve the interfacial problems of MFCs.     

Study on the effect of Ti,Al, Cu,and Ag doping on the bonding properties of soldered β-Sn(100)/ZrO2(111) interface

Selecting active elements for filler metal is very important in soldering of ZrO₂ ceramics. In this paper, the effects of Ti, Al, Cu, and Ag active elements on the bonding strength and electronic structures of soldered β-Sn(100)/ZrO₂(111) interface were studied via the method of first principle calculation. The work of adhesion (W_ad) results show that the O₂-terminated interface is more stable than other kinds of interfaces. Then, the atoms of Ti, Al, Cu, and Ag were doped into the interface by replacing the Sn atom in situ. It is found that additions of Ti, Al, and Cu atoms can increase the W_ad, and Ag atom has the opposite effect. From the results of heat of segregation, doping Ti and Al into the interface is stable in thermodynamics and doping Cu and Ag is not stable. The forming of strong ionic-covalent Ti-O and Al-O bonding contributes to the increase of the interfacial adhesion strength. The calculation results indicate that Ti and Al can act as active elements in Sn to solder ZrO₂. The Ti-O and Al-O compounds formed at interface can improve the wetting and bonding between Sn-based solder and ZrO₂ ceramics.     

PPS/PA66/HNTs复合材料的制备与性能研究

采用熔融共混方法制备了聚苯硫醚(PPS)/尼龙-66(PA66)/埃洛石纳米管(HNTs)复合材料,研究了其力学性能、热性能及其微观形态.结果表明:当PPS/PA66的比为60/40、HNTs的含量为30%时,复合材料具有较好的性能.复合材料的拉伸强度、弯曲模量及缺口抗冲击强度相对纯PPS分别提高了36.6%、163....