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Wang C.,Sun Yat Sen University | Wang C.,Key Laboratory of Polymeric Composites and Functional Materials | Wang C.,Key Laboratory of Designed Synthesis and Application of Polymer Material of Guangdong Province | Zhang Z.,Sun Yat Sen University | And 11 more authors.
Thermochimica Acta | Year: 2011

β-Polypropylene/poly (styrene-co-acrylonitrile) blends (β-PP/AS) were prepared with PP, a novel supported β-nucleating agent (β-NA) and AS (method one) or β-nucleated PP and AS (method two). The influence of AS on the β-nucleation for β-nucleated PP has been analyzed. The results indicated that PP with high content of β-crystal was obtained by adding β-NA into PP. The DSC studies showed that AS and its content had little effect on crystallization and melting characteristics of β-nucleated PP, and the content of β-crystal calculated from WAXD is higher than 0.94 in all blends. β-PP/AS blends with high content of β-crystal were obtained easily. AS dispersed mainly into β-spherulite of PP as small spherular particles, and the integrity of β-spherulite decreases gradually with the increase of AS content. The etched experiment also proved that β-NA dispersed in the AS phase or interface between PP and AS. © 2011 Elsevier B.V.


Jiang J.,Sun Yat Sen University | Li G.,Key Laboratory of Polymeric Composites and Functional Materials | Liu H.,Key Laboratory of Polymeric Composites and Functional Materials | Ding Q.,Sun Yat Sen University | Mai K.,Sun Yat Sen University
Composites Part A: Applied Science and Manufacturing | Year: 2012

In order to prepare the zeolite filled β-iPP composites, zeolite supported by calcium pimelate as β-nucleator (β-zeolite) was prepared by the interaction between calcified zeolite and pimelic acid. The effects of Ca(Ac) 2 solution concentration in the prepared calcified zeolite process and pimelic acid content on β-nucleating ability of β-zeolite were investigated and the crystallization and melting characteristic of zeolite, calcified zeolite and β-zeolite filled iPP composites were compared. DSC and WXAD analysis indicated that the zeolite and calcified zeolite have α-nucleation and the prepared β-zeolite has high β-nucleating ability for iPP crystallization. The β-nucleating ability of prepared β-zeolite is dependent of Ca(Ac) 2 solution concentration and pimelic acid content. The prepared β-zeolite content has little influence on the crystallization and melting characteristic and the β-phase content of the filled iPP composites. The zeolite filled β-iPP composites with high β-phase content can be easily obtained by adding β-zeolite into the iPP matrix. © 2012 Elsevier Ltd.


Ding Q.,Sun Yat Sen University | Ding Q.,Key Laboratory of Polymeric Composites and Functional Materials | Zhang Z.,Sun Yat Sen University | Zhang Z.,Key Laboratory of Polymeric Composites and Functional Materials | And 8 more authors.
Thermochimica Acta | Year: 2012

In order to obtain wollastonite filled β-iPP composites, wollastonite treated with pimelic acid (W*) were prepared with various mass ratios of wollastonite/pimelic acid (W/PA). The crystallization behavior, melting characteristics and β-nucleating ability of iPP composites filled with wollastonite (W) and W* were investigated by DSC and XRD. The results indicated that addition of wollastonite increased the crystallization temperatures of iPP, but the crystallization temperatures of iPP in iPP/W* composites were higher than those of iPP/W composites, which proved that the β-nucleation of W* is stronger than untreated wollastonite. Although iPP/wollastonite composites mainly form α-phase iPP, modification of wollastonite by PA significantly enhanced nucleation of β-phase iPP. The β-nucleating ability of W* depend on the amount of formed calcium pimelate, therefore the β-phase contents of β-iPP/W* composites increased with increasing W* content and decreasing mass ratio of W/PA. Moreover, there exist different critical mass ratios of W/PA for preparation of β-iPP composites filled with different W* contents with highest β-phase content and low cost. © 2012 Elsevier B.V. All rights reserved.


Jiang J.,Sun Yat Sen University | Jiang J.,Key Laboratory of Polymeric Composites and Functional Materials | Li G.,Key Laboratory of Polymeric Composites and Functional Materials | Li G.,Sun Yat Sen University | And 5 more authors.
Thermochimica Acta | Year: 2012

In order to prepare the zeolite filled β-iPP composites, the calcium pimelate as β-nucleator supported on the surface of zeolite (β-zeolite) was prepared by the interaction between calcified zeolite and pimelic acid. The β-nucleation, crystallization behavior and melting characteristic of zeolite, calcified zeolite and β-zeolite filled iPP composites were investigated by differential scanning calorimetry and wide-angle X-ray diffractometer. The results indicated that addition of the zeolite and calcified zeolite as well as β-zeolite increased the crystallization temperature of iPP. The zeolite and calcified zeolite filled iPP composites mainly crystallized in the α-crystal form and the strong β-heterogeneous nucleation of β-zeolite results in the formation of only β-crystal in β-zeolite filled iPP composites. The zeolite filled β-iPP composites with high β-crystal contents (above 0.90) can be easily obtained by adding β-zeolite into iPP matrix. © 2012 Elsevier B.V. All rights reserved.


Dai X.,Key Laboratory of Polymeric Composites and Functional Materials | Dai X.,Sun Yat Sen University | Zhang Z.,Key Laboratory of Polymeric Composites and Functional Materials | Zhang Z.,Sun Yat Sen University | And 8 more authors.
Composites Part A: Applied Science and Manufacturing | Year: 2013

Montmorillonite (MMT) generally has α-nucleating ability for isotactic polypropylene (iPP). A novel MMT with β-nucleating surface (β-MMT) supported by chemically calcium pimelate (CaA) was prepared through the chemical reaction between pimelic acid (HA) and calcium ion on the surface of MMT in the first time. Infrared spectrometry and thermogravimetric analysis confirmed the formation of CaA on the surface of MMT. The differential scanning calorimeter and X-ray diffraction illustrated that the iPP nanocomposites filled by MMT and β-MMT exhibit different heterogeneous nucleation. The heterogeneous nucleation of the prepared MMT surface has changed from α-nucleation into β-nucleation and a novel MMT with β-nucleating surface is obtained. Even, the heterogeneous β-nucleating ability of β-MMT is much stronger than that of CaA. Addition of MMT with β-nucleating surface into iPP matrix significantly increased the spherulite nuclei density and decreased the spherulite size, and can easily prepare the β-iPP nanocomposites with high relative β-phase content. © 2013 Elsevier Ltd. All rights reserved.


Li M.,Sun Yat Sen University | Li M.,Key Laboratory of Polymeric Composites and Functional Materials | Li G.,Key Laboratory of Polymeric Composites and Functional Materials | Jiang J.,Sun Yat Sen University | And 4 more authors.
Composites Science and Technology | Year: 2013

In order to increase the antimicrobial functionality of polypropylene random copolymer (PPR), nano-ZnO-supported on the surface of zeolite particles were prepared and used as functional fillers for PPR composites. The prepared nano-ZnO-supported zeolite particles were characterized by fluorescence and UV-Vis spectra, inductive coupled plasma and scanning electron microscopy. The crystallization behavior and crystalline morphology, antimicrobial ability and mechanical properties of zeolite, ZnO and nano-ZnO-supported zeolite filled PPR composites were investigated by differential scanning calorimeter, polarizing optical microscopy, antimicrobial and mechanical testing. The results indicated that the ZnO with flower-like morphology was formed on the surface of zeolite particles. The heterogeneous nucleation of zeolite and nano-ZnO-supported zeolite increase the crystallization temperature of PPR. The crystallization temperatures of nano-ZnO-supported zeolite filled PPR composites increase with increasing ZnO content in the nano-ZnO-supported zeolite. Incorporation of nano-ZnO-supported zeolite significantly decreases the size of spherulites of PPR. The nano-ZnO-supported zeolite filled PPR composites exhibit higher antimicrobial abilities than nano-ZnO filled PPR composite prepared by directly adding the same content of nano-ZnO into PPR matrix for the Staphylococcus aureus and Escherichia coli due to the flower-like morphology of ZnO in the nano-ZnO-supported zeolite. The nano-ZnO-supported zeolite content has little influence on the mechanical properties of PPR composites. nano-ZnO-supported zeolite as functional filler can be used to increase the antimicrobial ability of PPR. © 2013 Elsevier Ltd.

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