Detecting crystallization structure evolution of polypropylene injection‐molded bar induced by nucleating agent

2008 ◽  
Vol 48 (8) ◽  
pp. 1532-1541 ◽  
Author(s):  
Hongwei Bai ◽  
Yong Wang ◽  
Bo Song ◽  
Yanli Li ◽  
Li Liu
Keyword(s):  
Nucleating Agent ◽  
Structure Evolution ◽  
Injection Molded ◽  
Crystallization Structure

scholarly journals Crystalline modification of a rare earth nucleating agent for isotactic polypropylene based on its self-assembly

2018 ◽  
Vol 5 (5) ◽  
pp. 180247 ◽  
Author(s):  
Yuanming Zhang ◽  
Tingting Sun ◽  
Wei Jiang ◽  
Guangting Han
Keyword(s):  
Hydrogen Bond ◽  
Rare Earth ◽  
Isotactic Polypropylene ◽  
Self Assembly ◽  
Dendritic Structure ◽  
Nucleating Agent ◽  
The Self ◽  
Structure Evolution ◽  
Crystalline Modification ◽  
Assembly Structure

In this paper, the crystalline modification of a rare earth nucleating agent (WBG) for isotactic polypropylene (PP) based on its supramolecular self-assembly was investigated by differential scanning calorimetry, wide-angle X-ray diffraction and polarized optical microscopy. In addition, the relationship between the self-assembly structure of the nucleating agent and the crystalline structure, as well as the possible reason for the self-assembly behaviour, was further studied. The structure evolution of WBG showed that the self-assembly structure changed from a needle-like structure to a dendritic structure with increase in the content of WBG. When the content of WBG exceeded a critical value (0.4 wt%), it self-assembled into a strip structure. This revealed that the structure evolution of WBG contributed to the K β and the crystallization morphology of PP with different content of WBG. In addition, further studies implied that the behaviour of self-assembly was a liquid–solid transformation of WBG, followed by a liquid–liquid phase separation of molten isotactic PP and WBG. The formation of the self-assembly structure was based on the free molecules by hydrogen bond dissociation while being heated, followed by aggregation into another structure by hydrogen bond association while being cooled. Furthermore, self-assembly behaviour depends largely on the interaction between WBG themselves.

Morphology design of isotactic polypropylene composites

2017 ◽  
Vol 31 (9) ◽  
pp. 1252-1262
Author(s):  
Shiwei Wang ◽  
Yuting Leng ◽  
Guangan Zhang ◽  
Ruonan Wang ◽  
Shuaijiang Ma ◽  
...  
Keyword(s):  
Isotactic Polypropylene ◽  
High Performance ◽  
Polarized Light ◽  
Nucleating Agent ◽  
Interfacial Region ◽  
Polypropylene Composites ◽  
Composites Materials ◽  
High Performance Polymer ◽  
Injection Molded ◽  
New Perspective

In this article, the high-performance polymer composites were prepared based on the morphology designing method. To begin with, the beta transcrystalline morphology in the interfacial region of isotactic polypropylene (iPP) composites supported by single carbon fiber was formed by the induction of beta nucleating agent (NA) and verified using the polarized light microscopy. Then, to further explore the application of the beta transcrystalline morphology, the way of induction by supported NA was introduced into the iPP injection-molded samples. The result showed that a certain number of interfacial beta transcrystallinity was formed in the adjacent region of carbon nanotubes–modified iPP injection-molded samples. Herein, the mechanical properties are closely related to the interfacial beta transcrystalline morphology, the convective evidence was the improvement of the sample’s impact strength by seven times. Therefore, this work gives a new perspective for the preparation of high-performance composites materials via morphology designing.

Enhanced orientation of the water-assisted injection-molded ipp in the presence of nucleating agent

2012 ◽  
Vol 52 (4) ◽  
pp. 725-732 ◽  
Author(s):  
Guo-Qiang Zheng ◽  
Zhenhua Jia ◽  
Xianhu Liu ◽  
Baochen Liu ◽  
Xiaoli Zhang ◽  
...  
Keyword(s):  
Nucleating Agent ◽  
Injection Molded

scholarly journals Comparison of the efficiency of the most effective heterogeneous nucleating agents for Poly(lactic acid)

2021 ◽  
Author(s):  
Tatyana Ageyeva ◽  
József Gábor Kovács ◽  
Tamás Tábi
Keyword(s):  
Lactic Acid ◽  
Tensile Modulus ◽  
Charpy Impact ◽  
Nucleating Agent ◽  
Poly Lactic Acid ◽  
Nucleating Agents ◽  
Scanning Calorimetry ◽  
Injection Molded ◽  
Heat Deflection Temperature ◽  
Charpy Impact Strength

AbstractWe selected the thirteen most effective nucleating agents for Poly(lactic acid) (PLA) from the literature, and synthesized and compounded them with two different PLA grades: 3001D (1.4% D-lactide content) and 3100HP (0.5% D-lactide content, considered PLLA). We determined the crystallinity and crystallization of PLA with different nucleating agents in identical conditions (same nucleating agent content, same cooling rate) with the help of differential scanning calorimetry. We compared the efficiency of each nucleating agent and found that for both PLA grades, Zinc PhenylPhosphonate was the most effective. However, even when nucleated PLA was injection molded into a cold mold (25 °C), it still could not fully crystallize during cooling and the heat deflection temperature did not increase significantly. The maximum achieved crystallinity, in this case, was between 32.4 and 35.7%. On the contrary, when a 90 °C “hot mold” and in-mold crystallization together were applied, the specimens achieved full crystallization during the injection molding cycle (crystallinity was between 44.5 and 50.0%), and the heat deflection temperature increased to an average of 88.8 °C. We also examined the mechanical properties of the nucleated PLA and found that the usage of nucleating agents together with a hot mold improved tensile strength, tensile modulus, and Charpy impact strength but decreased elongation at break.

scholarly journals From disposal to sustainable development: technological potential of poly(lactic acid) (PLA) blends with 3D filament waste

2020 ◽  
Vol 9 (12) ◽  
pp. e13291210767
Author(s):  
Wellerson Salomão Diniz Marinho ◽  
Carlos Bruno Barreto Luna ◽  
Edcleide Maria Araújo ◽  
Carlos Heitor de Andrade Lustosa ◽  
Celso Rosendo Bezerra Filho ◽  
...  
Keyword(s):  
Sustainable Development ◽  
Softening Temperature ◽  
Nucleating Agent ◽  
Degree Of Crystallinity ◽  
Poly Lactic Acid ◽  
Continuous Growth ◽  
Technological Potential ◽  
Twin Screw ◽  
Injection Molded ◽  
The Degree Of Crystallinity

Additive manufacturing is growing rapidly in the automotive, medical, and aerospace industries as an option for the manufacturing of products. However, there is a continuous growth in the amount of waste generated by 3D filaments, thus, the reuse practice becomes important, since it brings environmental and economic gains. The present research evaluated the mechanical, thermal, thermomechanical and rheological properties of PLA/PLAr blends containing post-consumption 3D filament. The blends were prepared in a co-rotational twin screw extruder and, subsequently, the extruded granules were injection molded. As the PLAr content in the blends (PLA/PLAr) increased, there was a reduction in viscosity, indicating an improvement in manufacturability. The PLA/PLAr blend (75/25 % wt.) increased the degree of crystallinity compared to neat PLA, indicating that PLAr acted as a nucleating agent. As a consequence, the PLA/PLAr blend (75/25 % wt.) showed performance comparable to neat PLA in thermal stability, elastic modulus, tensile strength, Shore D hardness, impact strength, heat deflection temperature (HDT) and Vicat softening temperature. The reuse of post-consumption 3D filament PLA is feasible for the development of materials with good properties. In addition, value is added to the post-consumption material and there is a contribution to sustainable development.

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