Influences of the Crystallization Behavior of n-HA Reinforced PA66 Biocomposite on Its Mechanical Properties

2006 ◽  
Vol 510-511 ◽  
pp. 898-901 ◽  
Author(s):  
Xiang Zhang ◽  
Yu Bao Li ◽  
Yi Zuo ◽  
Guo Yu Lv ◽  
Yuan Hua Mu

The crystallization behavior of n-HA/PA66 biocomposites at different processing pressure and annealing temperature were investigated by XRD and DSC. The results showed that increasing annealing temperature would weaken the crystalline intensities of pure PA66 and its composites. For n-HA/PA66 composites, the peaks of α1 crystals of PA66 disappeared, only α2 crystals existed, and with the increase of injection pressure and annealing temperature, the crystalline intensity of PA66 decreased. The degree of crystallinity (Xc) of PA66 in composites increased with the increase of injection pressure, however, annealing temperature had no obvious effects on crystalline degree. The mechanical properties had close relationship with the crystallization behavior of the materials.

2016 ◽  
Vol 16 (4) ◽  
pp. 4147-4152 ◽  
Author(s):  
Huiwen Liu ◽  
Jing Yang ◽  
Honglin Yu ◽  
Xiaoxuan Zou ◽  
Bo Jing ◽  
...  

The dynamic mechanical properties, crystallization behavior and morphology of nanoscale Tg tin fluorophosphate glass (TFP glass)/polyamide 66 (PA66) hybrid materials were investigated by XRD, DSC and SEM. The experimental results showed that the Tg of TFP/PA66 hybrid decreased and the third relaxation in the highly filled hybrid appeared due to the interaction between the TFP glass and amide groups of PA66. The storage modulus of the hybrid materials increased with increase in the content of TFP at low temperatures but had little effect at high temperatures. This result was attributed to the stiffness depression of the TFP glass when the temperature rose above its Tg and the similar elasticity of the two phases because of the interaction between the components. The degree of crystallinity and α, γ crystal content of PA66 both decreased due to the interaction between the two phases. In addition, the phase defect, the size distribution and the compatibility of TFP in the PA66 matrix were discussed by SEM, the results showed that the TFP appeared aggregation partly, but had the favorable compatibility in the PA66 matrix.


Author(s):  
С.В. Зайцев ◽  
В.С. Ващилин ◽  
В.В. Колесник ◽  
М.В. Лимаренко ◽  
Д.С. Прохоренков ◽  
...  

AbstractZinc-oxide films 1.4 μm in thickness are deposited onto glassy substrates by the dual magnetron-assisted sputtering of zinc targets in an argon and oxygen gas atmosphere. The dependences of the structural and optical characteristics of the ZnO films on the temperature of postdeposition photonic annealing are studied. It is established that an increase in the annealing temperature yields an increase in the degree of crystallinity of the films. Electron microscopy shows that the deposited ZnO coatings are columnar in structure and the microstructure density and crystallite size increase upon annealing. It is found that, at an annealing temperature of 450–650°C, the optical transmittance increases to >90% in the spectral range 400–1100 nm. The experimental results show that the temperature of vacuum photonic annealing has the most profound effect on the final properties of ZnO coatings.


2019 ◽  
Vol 951 ◽  
pp. 21-25
Author(s):  
Achmad Chafidz ◽  
Sholeh Ma'mun ◽  
Haryanto ◽  
Wara Dyah Pita Rengga ◽  
Prima A. Handayani ◽  
...  

In this study, PP/clay nanocomposites have been fabricated at different nanoclay loadings, i.e. 0, 5, 10, and 5 wt% for the 1stcycle and 2ndcycle (re-processing). The prepared nanocomposites were then characterized by a Differential Scanning Calorimetry (DSC) to investigate the effects of nanoclay loadings and re-processing on the melting and crystallization of the nanocomposites. The DSC results showed that the melting temperature,Tmwas not significantly affected by the nanoclay loadings and re-processing. In the other hand, the degree of crystallinity,Xcof the nanocomposites was higher than that of neat PP, but only reached a maximum at nanoclay loading of 5 wt% (i.e. 51.2% for NC-5-I and 48.3% for NC-5-II). Thereafter, theXcdecreased at higher nanoclay loadings. There was no significant difference inXcbetween 1stcycle and 2ndcycle. Additionally, in all nanocomposites samples for both cycles, there were two crystallization temperatures, i.e.Tc1andTc2. In the overall crystallization process, theTcof nanocomposites increased by 11-12°C compared to that of neat PP. Whereas, the onset crystallization temperature,Tocalso increased by approx. 13°C. Apparently, there was no significant effect of nanoclay loadings and re-processing on theTcndTocof the nanocomposites.


2018 ◽  
Vol 26 (2(128)) ◽  
pp. 26-31 ◽  
Author(s):  
Munir Hussain ◽  
Feichao Zhu ◽  
Feichao Zhu ◽  
Bin Yu ◽  
Bin Yu ◽  
...  

The thermal properties and morphological characterisation of isotactic polypropylene (iPP) homopolymer and its blends with low molecular low modulus polypropylene (LMPP) were studied. Firstly blends were prepared with variant LMPP contents, and their properties were characterised using SEM, DSC, XRD, and DMA. Later the mechanical properties of iPP/LMPP blend fibres were investigated. SEM results showed that the iPP/LMPP blends produced smoother surfaces when the LMPP content was increased, as well as the miscibility. All the Tg values with different LMPP percentages were in-between pure iPP and LMPP. The XRD results indicated the LMPP percentage decreased along with the degree of crystallinity of the iPP/LMPP blends (5% to 15%), which increased and then decreased as compared to pure iPP. The elongation at break increased when the LMPP content increased, with the maximum breaking elongation of the LMPP 25% blend reaching 12.95%, which showed great stretch-ability, whereas the elastic modulus of iPP/LMPP blends decreased.


Polymers ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 23 ◽  
Author(s):  
Tarek Dayyoub ◽  
Aleksey Maksimkin ◽  
Sergey Kaloshkin ◽  
Evgeniy Kolesnikov ◽  
Dilus Chukov ◽  
...  

Highly oriented UHMWPE films were reinforced with functionalized graphene nanoplates (GNP). GNP was functionalized by deposition of polyaniline (PANI) on the GNP surface. The structure of GNP/PANI was studied by Raman spectroscopy, and the structure of xerogels and films based on UHMWPE was studied by DSC and SEM. PANI promotes the reduction of the GNP aggregation in the UHMWPE matrix and increases the degree of crystallinity due to heterogeneous crystallization. The new lamellar crystal structure has a high drawability. The highest value of the tensile strength 1330 MPa (an increase of 45%) was obtained with a filler content of 2 wt % GNP/PANI, and the highest value of Young’s modulus 41 GPa (an increase of 32%) was obtained with a filler content of 1 wt % GNP/PANI. The effect of GNP with PANI fillers on the dynamic mechanical properties of the UHMWPE films was discussed.


Tribologia ◽  
2018 ◽  
Vol 278 (2) ◽  
pp. 95-101
Author(s):  
Aneta NIEMIEC

The article presents the results of research on the impact of structural changes in polyether ether ketone (PEEK) on its mechanical properties. The polymer was exposed to gamma radiation at a dose of 50 and 150 kGy, and the radiation energy was 4 MeV. Changes in the degree of crystallinity and the related changes in the glass transition and melting temperature for the polymer were determined by differential scanning calorimetry (DSC). Mechanical properties were determined using the micro-mentoring method. The tests showed a change in the degree of crystallinity in the range of several degrees and a significant increase in the glass transition temperature. In terms of mechanical properties, the reduction of hardness and Young’s modulus was observed. Observed changes, especially in terms of changes in the structure of the polymer under the influence of radiation, are difficult to explain, which requires conducting further research, especially in the range of irradiation parameters used. Further research is important because PEEK is used in many fields, especially in conditions conducive to corrosion and the influence of radiation.


2011 ◽  
Vol 13 (3) ◽  
pp. 61-65 ◽  
Author(s):  
Agnieszka Szczygielska ◽  
Jacek Kijeński

Studies of properties of polypropylene/halloysite compositesThe results of the studies on the synthesis, mechanical and thermal properties of polypropylene composites with various amount of halloysite filler are presented. Halloysite (HNT) belongs to the silica type characterized by a two-layer 1:1 structure. This work was aimed to develop a method for the modification of halloysite in its prime use as a filler for polypropylene by extrusion. The composites contain 1, 3, 5 and 7 wt.% of HNT. The degree of crystallinity of the composites decrease with increasing halloysite content. The results confirm the expectations that composites of interesting physicochemical, mechanical and thermal properties can be obtained. The mechanical properties studied show that the filler modification method used leads to the synthesis of polymer composites of improved thermal and mechanical properties.


2013 ◽  
Vol 774-776 ◽  
pp. 856-859
Author(s):  
Hong Peng Zhong ◽  
Ahmed DawElbeit ◽  
Hai Juan Kong ◽  
Chun Mao Kang ◽  
Mei Hua ◽  
...  

The heat treatment was carried out to modify the aramid fibers, and the effect of tension on the mechanical properties and structure was investigated through Fiber Strength Equipment, viscosity, XRD and SEM . The results show that fibers,strength slightly decrease, but modulus increase significantly according to the increasing of tension at 480°C and 10s, and reach a maximum when the tension value is 300 g. After heat treatment, molecular weight decrease and the degree of crystallinity increase. SEM show that there is little effect on the surface topography of the fibers during treatment.


2017 ◽  
Vol 37 (6) ◽  
pp. 559-576 ◽  
Author(s):  
Xiaoyan Zhang ◽  
Xiangmin Xu ◽  
Tao Wu

Abstract In this study, two different surface-modified silica nanoparticles, amino-functionalized nanosilica (ATS) and methyl-functionalized nanosilica (HDS), were separately used as nanofillers to fabricate PA66-based nanocomposites by melt blending. The morphology and interface characteristics of the two nanofillers in the composite system and their influence on the mechanical properties, thermal decomposition behavior, and crystallization behavior of PA66 were investigated. The Avrami and Mo methods were applied to study the non-isothermal crystallization kinetics of the nanocomposites. The results revealed that different surface modifications of silica nanoparticles can produce different influences on the mechanical properties and thermal decomposition behavior of the final nanocomposites. The addition of ATS helps increase the strength and stiffness of PA66/ATS nanocomposites, and in the meantime enhances the thermal stability of PA66. The case of HDS is opposite to that of ATS; however, its incorporation can improve the toughness of the material. In addition, the results also indicate that ATS possesses strong heterogeneous nucleation capability, the introduction of which can accelerate the crystallization rate and increase the crystallization temperature, as well as the degree of crystallinity of PA66, while HDS displays an obvious blocking effect on the crystallization process of PA66.


2006 ◽  
Vol 514-516 ◽  
pp. 951-955 ◽  
Author(s):  
Carlos M. Costa ◽  
Vitor Sencadas ◽  
João F. Mano ◽  
Senentxu Lanceros-Méndez

In this work, mechanical and thermal experimental techniques have been applied in order to relate the mechanical response with the microscopic variations of the material. Stress-strain results along the main directions of β-poly(vinylidene fluoride), β-PVDF, in poled and non-poled samples enables to investigate the influence of the poling process on the mechanical response of the material. Further, differential scanning calorimetry experiments allow the investigation of the effect of poling in the degree of crystallinity of the material as well as on the stability of the crystalline phase. Thermogravimetric analysis was used to investigate the kinetics of the thermal degradation of poled and non-poled β-PVDF samples. The differences observed between the two materials suggest that the poling affects the mechanical properties of the material especially in the direction parallel to the polymeric chains and originates changes at a molecular level that remain beyond the melting of the material.


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