Effects of organic nucleating agents and zinc oxide nanoparticles on isotactic polypropylene crystallization

Tang, Jianguo; Wang, Yao; Liu, Haiyan; Belfiore, Laurence A.

doi:10.1016/j.polymer.2003.11.046

Cited by 126 publications

(57 citation statements)

References 32 publications

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“…Observa-se na Figura 1(a), que a amostra TPU 1, na presença de agente nucleante, deslocou a temperatura máxima do pico de cristalização, T c , para valores superiores ao do polímero original, evidenciando seu efeito nucleante, facilitando a cristalização. Este mesmo comportamento foi observado em trabalhos com o polipropileno [9,10,11]. No entanto, para a amostra TPU 2 Figura 1(b), de menor massa molar, a variação da T c em função da adição de talco foi menos pronunciada.…”

Section: Calorimetria Exploratória Diferencial (Dsc)unclassified

Efeito da incorporação de talco nas características térmicas, mecânicas e dinâmico-mecânicas de poliuretanos termoplásticos

et al. 2011

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RESUMOO objetivo deste trabalho foi investigar o efeito da adição de talco, um agente nucleante amplamente empregado em formulações de termoplásticos em geral, no comportamento de cristalização e nas propriedades mecânicas de dois poliuretanos termoplásticos (TPUs) de diferentes massas molares. Foram realizadas análises de calorimetria exploratória diferencial (DSC), termogravimetria (TGA), dinâmico-mecânica (DMA), além de ensaios mecânicos. Observou-se que a adição de talco aumentou a temperatura de cristalização e a de decomposição média do TPU de maior massa molar média, no entanto, não foi observada mudança para concentrações superiores a 0,5% (m/m). Análises de DMA indicaram um aumento do módulo de armazenamento com a aditivação somente para o TPU de maior massa molar média. Nos ensaios mecânicos, não foi possível observar alterações significativas nas propriedades. O estudo realizado demonstrou a importância do conhecimento do efeito da adição de talco como agente nucleante em compostos de TPU, visando o melhoramento do desempenho destes materiais. Palavras -chave:Talco, poliuretano termoplástico, agente nucleante, cristalização.The effect of talc addition on the thermal, mechanical and dynamicmechanical characteristics of thermoplastic polyurethanes ABSTRACTThe aim of this work was to investigate the effect of adding talc, a nucleating agent widely used in general purpose thermoplastic formulations, on the crystallization behavior and the mechanical properties of two thermoplastic polyurethanes (TPUs) of different molecular weight. In this study, differential scanning calorimetry (DSC), thermogravimetry (TGA), dynamic-mechanical analysis (DMTA) and mechanical tests were employed. It was observed that the addition of talc increased the crystallization and the decomposition temperature of the highest average molecular weight TPU, although no change was observed at concentrations above 0.5 wt%. DMA analyses showed an increase in storage modulus only for the TPU with the highest average molecular weight. Mechanical testing did not show significant changes in the evaluated properties. The study demonstrated the importance of knowing the particular effects of adding talc as a nucleating agent in TPU compounds, aimed at improving their performance.Keywords: Talc, thermoplastic polyurethane, nucleating agent, crystallization. INTRODUÇÃOA necessidade de se produzir materiais com menor custo e maior disponibilidade no mercado tornou-se um dos grandes desafios para a indústria de componentes para calçados. No setor de laminados, por exemplo, é de grande importância o desenvolvimento de materiais com boas propriedades adesivas que aliem baixa temperatura de processamento e curto tempo de cristalização.O poliéster à base de caprolactona (PES) apresenta custo relativamente elevado e baixa disponibilidade no mercado, sendo prioritariamente utilizado para aplicações mais atraentes economicamente, como na área médica. Por estes motivos, é crescente o interesse em substituir o PES,

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Section: Calorimetria Exploratória Diferencial (Dsc)unclassified

Efeito da incorporação de talco nas características térmicas, mecânicas e dinâmico-mecânicas de poliuretanos termoplásticos

et al. 2011

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“…Due also to low cost, ZnO particles (with sub-micro and nano-dimensions) are therefore ideal fillers for polymers to be applied in the field of active food packaging. Thus, ZnO particles have been incorporated into a number of different polymers used in food packaging [15,16], such as low-density polyethylene (LDPE) [17,18], isotactic polypropylene (iPP) [19][20][21][22][23][24], polyamide (PA) [18,25], and polylactic acid (PLA) [26].…”

Section: Introductionmentioning

confidence: 99%

Development of Antibacterial Composite Films Based on Isotactic Polypropylene and Coated ZnO Particles for Active Food Packaging

et al. 2016

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This study was aimed at developing new films based on isotactic polypropylene (iPP) for food packaging applications using zinc oxide (ZnO) with submicron dimension particles obtained by spray pyrolysis. To improve compatibility with iPP, the ZnO particles were coated with stearic acid (ZnOc). Composites based on iPP with 2 wt % and 5 wt % of ZnOc were prepared in a twin-screw extruder and then filmed by a calender. The effect of ZnOc on the properties of iPP were assessed and compared with those obtained in previous study on iPP/ZnO and iPP/iPPgMA/ZnO. For all composites, a homogeneous distribution and dispersion of ZnOc was obtained indicating that the coating with stearic acid of the ZnO particles reduces the surface polarity mismatch between iPP and ZnO. The iPP/ZnOc composite films have relevant antibacterial properties with respect to E. coli, higher thermal stability and improved mechanical and impact properties than the pure polymer and the composites iPP/ZnO and iPP/iPP-g-MA/ZnO. This study demonstrated that iPP/ZnOc films are suitable materials for potential application in the active packaging field.

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“…Usually, nucleating agents can be classified as organic and inorganic. There are lots of researches that focus on PP crystallization via organic nucleating agents, and also a few hundred publications about inorganic nucleating agents, such as glass fiber, 3 calcium carbonate (CaCO 3 ), 4 silicon dioxide (SiO 2 ), 5 talc, 6 zinc oxide (ZnO) 7 and clay, 8 but little has been reported using CB as a nucleating agent. 9,10 CB is one of the industrially important and commercially available carbon materials, which has excellent properties, such as heat, chemical and weather resistance, light weight, electro-conductivity, and low thermal expansion.…”

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confidence: 99%

“…Moreover, fillers with small particle size and narrow size distribution can lead to much higher nucleation densities in the matrix. Tang et al 7 observed an increase in the nucleation densities when the particle size of ZnO is below 100 nm and nano ZnO as a nucleating agent is more efficient than micro ZnO. It can be presumed that if the particle size of MCB had de-creased to the nanoscale size, it would be more efficient.…”

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confidence: 99%

Crystallization Behavior of Polypropylene Filled with Modified Carbon Black

Chen

2007

Polym J

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ABSTRACT:A novel method was employed to modify the surface of carbon black (CB) by organic small molecules in a Haake Rheomix mixer. The investigations of Thermo Gravimetric Analysis (TGA), transmission electron microscopy (TEM), Flourier Transform Infrared spectroscopy (FT-IR) and X-ray Photoelectronic Spectroscopy (XPS) indicated that organic small molecules were grafted onto the surface of MCB and the particle size of MCB was reduced notably. Then the crystallization behavior of polypropylene (PP)/MCB composite as well as pure PP and PP/CB composite were investigated via differential scanning calorimeter (DSC), wide angle X-ray diffraction (WAXD) and optical polarizing microscope (POM). It was found that both CB and MCB can influence the crystallization behavior of PP and provide nucleation sites to the matrix. However, MCB accelerated the crystallization rate and increased the crystallization peak temperature of PP more evidently than CB did. In the case of non-isothermal crystallization, Jeziorny and Mo Equations were used to analyze the data of DSC and both could describe these systems. Finally, the nucleation activity of MCB was evaluated. It was proved that the nucleation activity of MCB was higher than that of CB at the same concentration.

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Effects of organic nucleating agents and zinc oxide nanoparticles on isotactic polypropylene crystallization

Cited by 126 publications

References 32 publications

Efeito da incorporação de talco nas características térmicas, mecânicas e dinâmico-mecânicas de poliuretanos termoplásticos

Efeito da incorporação de talco nas características térmicas, mecânicas e dinâmico-mecânicas de poliuretanos termoplásticos

Development of Antibacterial Composite Films Based on Isotactic Polypropylene and Coated ZnO Particles for Active Food Packaging

Crystallization Behavior of Polypropylene Filled with Modified Carbon Black

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