1
|
Influence of Crystal Structure on Thermo-Mechanical Properties of Injection Molded 𝛃-Nucleated iPP. INT POLYM PROC 2021. [DOI: 10.1515/ipp-2020-4106] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Isotactic polypropylene (iPP) was nucleated in-situ with calcium pimelate during melt compounding. Calcium pimelate is a highly effective β-nucleator for isotactic polypropylene (iPP). The β-nucleated iPP was characterized by wide angle x-ray diffraction (WAXD) and differential scanning calorimetry (DSC) for its crystallinity and crystal structure. In addition, the injection-molded samples were tested for thermo-mechanical properties. It is found that very low quantity (< 0.1 wt. %) of β-nucleator is required to produce sufficiently high β-crystal fraction (Kβ) in isotactic polypropylene. β-nucleated iPP shows increment of 11 to 14 °C in its heat deflection temperature (HDT). It was also observed that slow cooling rate of β-nucleated iPP promotes the formation of β-crystals and that tensile stretching leads to complete transformation of β crystals into a-crystals at room temperature. It was also revealed that the presence of maleic anhydride grafted polypropylene (PP-g-MA), a well-known coupling agent (or compatibilizer), may reduce the (Kβ) value to a marginal extent. It was also observed that the thermo-mechanical properties were not much affected by the presence of PP-g-MA. Therefore, calcium pimelate may be used as β-nucleator in case of neat as well as reinforced polypropylene containing maleic anhydride as coupling agent.
Collapse
|
2
|
Dave F, Ali MM, Sherlock R, Kandasami A, Tormey D. Laser Transmission Welding of Semi-Crystalline Polymers and Their Composites: A Critical Review. Polymers (Basel) 2021; 13:675. [PMID: 33668125 PMCID: PMC7956557 DOI: 10.3390/polym13050675] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 02/09/2021] [Accepted: 02/18/2021] [Indexed: 11/16/2022] Open
Abstract
The present review provides an overview of the current status and future perspectives of one of the smart manufacturing techniques of Industry 4.0, laser transmission welding (LTW) of semi-crystalline (SC) polymers and their composites. It is one of the most versatile techniques used to join polymeric components with varying thickness and configuration using a laser source. This article focuses on various parameters and phenomena such as inter-diffusion and microstructural changes that occur due to the laser interaction with SC polymers (specifically polypropylene). The effect of carbon black (size, shape, structure, thermal conductivity, dispersion, distribution, etc.) in the laser absorptive part and nucleating agent in the laser transmissive part and its processing conditions impacting the weld strength is discussed in detail. Among the laser parameters, laser power, scanning speed and clamping pressure are considered to be the most critical. This review also highlights innovative ideas such as incorporating metal as an absorber in the laser absorptive part, hybrid carbon black, dual clamping device, and an increasing number of scans and patterns. Finally, there is presented an overview of the essential characterisation techniques that help to determine the weld quality. This review demonstrates that LTW has excellent potential in polymer joining applications and the challenges including the cost-effectiveness, innovative ideas to provide state-of-the-art design and fabrication of complex products in a wide range of applications. This work will be of keen interest to other researchers and practitioners who are involved in the welding of polymers.
Collapse
Affiliation(s)
- Foram Dave
- Department of Mechanical and Manufacturing Engineering, Institute of Technology Sligo, Ash Lane, F91 YW50 Sligo, Ireland; (F.D.); (M.M.A.)
- Centre for Precision Engineering, Materials and Manufacturing (PEM) Centre, Institute of Technology Sligo, Ash Lane, F91 YW50 Sligo, Ireland;
| | - Muhammad Mahmood Ali
- Department of Mechanical and Manufacturing Engineering, Institute of Technology Sligo, Ash Lane, F91 YW50 Sligo, Ireland; (F.D.); (M.M.A.)
- Centre for Precision Engineering, Materials and Manufacturing (PEM) Centre, Institute of Technology Sligo, Ash Lane, F91 YW50 Sligo, Ireland;
| | - Richard Sherlock
- Centre for Precision Engineering, Materials and Manufacturing (PEM) Centre, Institute of Technology Sligo, Ash Lane, F91 YW50 Sligo, Ireland;
- Department of Life Sciences, School of Science, Institute of Technology Sligo, Ash Lane, F91 YW50 Sligo, Ireland
| | - Asokan Kandasami
- Materials Science Group, Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110 067, India; or
| | - David Tormey
- Department of Mechanical and Manufacturing Engineering, Institute of Technology Sligo, Ash Lane, F91 YW50 Sligo, Ireland; (F.D.); (M.M.A.)
- Centre for Precision Engineering, Materials and Manufacturing (PEM) Centre, Institute of Technology Sligo, Ash Lane, F91 YW50 Sligo, Ireland;
| |
Collapse
|
3
|
Synergetic Toughening Effect of Carbon Nanotubes and β-Nucleating Agents on the Polypropylene Random Copolymer/Styrene-Ethylene-Butylene- Styrene Block Copolymer Blends. Polymers (Basel) 2018; 11:polym11010029. [PMID: 30960013 PMCID: PMC6401747 DOI: 10.3390/polym11010029] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 12/20/2018] [Accepted: 12/23/2018] [Indexed: 12/03/2022] Open
Abstract
Polypropylene random co-polymer (PPR)/styrene-ethylene-butylene-styrene (SBS) block copolymer blends with high toughness and favorable tensile properties were successfully obtained by blending with traces of multi-wall carbon nanotubes (MWCNTs) and β-nucleating agents (β-NAs). β-NAs can effectively induce the ductile β-form crystal in the PPR matrix. Although the addition of MWCNTs was reported to be only benefit for the tensile strength of PPR and relatively disadvantageous for the toughness, the obviously synergistic toughening effect in PPR/SBS blends was found when MWCNTs and β-NAs coexisted. The notched izod impact strength of PPR/30 wt % SBS blend with MWCNTs and β-NAs increased from 11.3 to 58.9 kJ/m2; more than 5-fold increment compared with pure PPR. Meanwhile, the tensile strength retention of this PPR blend is still above 72.2%. The micro-morphology indicated that the MWCNTs can act as bridges between SBS particle and PPR matrix, effectively transferring the stress and absorbing impact energy among SBS particles.
Collapse
|
4
|
Kersch M, Schmidt HW, Altstädt V. Influence of different beta-nucleating agents on the morphology of isotactic polypropylene and their toughening effectiveness. POLYMER 2016. [DOI: 10.1016/j.polymer.2016.06.051] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
5
|
Zhang C, Liu G, Jiang Q, Zhao Y, Wang D. Correlation between the fracture toughness and β-crystal fraction in a β-nucleated propylene-based propylene-ethylene random copolymer. J Appl Polym Sci 2016. [DOI: 10.1002/app.42930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Chunbo Zhang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics; Institute of Chemistry, Chinese Academy of Sciences; Beijing 100190 China
| | - Guoming Liu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics; Institute of Chemistry, Chinese Academy of Sciences; Beijing 100190 China
| | - Qianhong Jiang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics; Institute of Chemistry, Chinese Academy of Sciences; Beijing 100190 China
| | - Ying Zhao
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics; Institute of Chemistry, Chinese Academy of Sciences; Beijing 100190 China
| | - Dujin Wang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics; Institute of Chemistry, Chinese Academy of Sciences; Beijing 100190 China
| |
Collapse
|
6
|
Obadal M, Cermák R, Habrová V, Stoklasa K, Šimoník J. Tensile and Flexural Properties of β-Nucleated Polypropylenes. INT POLYM PROC 2013. [DOI: 10.3139/217.1834] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
Resuming our previous work on β-nucleated polypropylenes, namely on their impact strength, our present work directs attention towards a flexural and tensile behavior of β-nucleated polypropylenes (β-iPP). For the purposes of this work, commercially available isotactic polypropylene was modified using various amounts of a specific nucleating agent based on N, N′-dicyclohexylnaphtalene-2,6-dicarboxamide (NU100). From the prepared blends test specimens were prepared by injection molding. Structural characterization (crystallinity and the content of β-phase) was carried out by X-ray diffractometry. A multipurpose mechanical property tester was used for determination of tensile and flexural properties. It was found that β-phase content decreased both tensile and flexural strength; on the other hand, the presence of β-phase dramatically raised cold drawability of the injection-molded specimens; addition of 0.03 wt.% of NU100 in the injection-molded parts led to a more than 800 % increase of the draw ratio of specimens tested at the testing speed of 100 mm/min. Furthermore, tensile testing carried out using various strain speeds (10 and 100 mm/min) revealed that higher ductility of the material containing β-phase is particularly pronounced by faster deformation processes, such as fast drawing or impact load.
Collapse
Affiliation(s)
- M. Obadal
- Department of Polymer Engineering, Tomas Bata University, Zlín, Czech Republic
| | - R. Cermák
- Department of Polymer Engineering, Tomas Bata University, Zlín, Czech Republic
| | - V. Habrová
- Department of Polymer Engineering, Tomas Bata University, Zlín, Czech Republic
| | - K. Stoklasa
- Department of Polymer Engineering, Tomas Bata University, Zlín, Czech Republic
| | - J. Šimoník
- Department of Polymer Engineering, Tomas Bata University, Zlín, Czech Republic
| |
Collapse
|
7
|
Development of β and α isotactic polypropylene polymorphs in injection molded structural foams. CHEMICAL PAPERS 2010. [DOI: 10.2478/s11696-009-0107-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AbstractStructural foam moldings, composed of three co-axial cylinders differing in diameter (10 mm, 20 mm, and 30 mm) and length, were produced from isotactic polypropylene (PP) and 0.5 mass % 1,1′-azobisformamide on an in-line injection molding machine in a mould cavity pre-pressurized with nitrogen by the classical low-pressure process combined with egression of foamed melt from the core. Injection-molding conditions were as follows: melt temperature, 220°C, mold temperature, 20°C, cooling time, 5 min, gas-counter pressure, 0.5 MPa. The sprue gate was at the end of the smallest cylinder and its diameter was varied from 4 mm to 7 mm. To investigate the development of β-PP modification in terms of phenomena due to the phase change in the mould cavity (expansion), appropriate specimens (cross-sections) were cut from the middle of each cylinder in parallel and perpendicular orientation to the flow direction and were investigated by WAXS, DSC, and POM. As revealed by WAXS, β-PP is present in all cylinders, always concentrated in certain regions of the cross-section — mainly in the surface layers of the smallest cylinder (D1) and in the foamed core of the other two cylinders (D2 and D3). Its concentration was found to change with the sprue dimensions. High β-PP concentration is associated with a preferred orientation in the skin of the smallest cylinder and with better expansion conditions in larger cylinders. Presence of the β-phase in the surface layers and in the core of the moldings was proved by DSC and POM.
Collapse
|
8
|
Chvátalová L, Navrátilová J, Čermák R, Raab M, Obadal M. Joint Effects of Molecular Structure and Processing History on Specific Nucleation of Isotactic Polypropylene. Macromolecules 2009. [DOI: 10.1021/ma9005878] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Lenka Chvátalová
- Faculty of Technology, Department of Polymer Engineering, Tomas Bata University in Zlín, nám. T. G. Masaryka 275, 762 72 Zlín, Czech Republic
| | - Jana Navrátilová
- Faculty of Technology, Department of Polymer Engineering, Tomas Bata University in Zlín, nám. T. G. Masaryka 275, 762 72 Zlín, Czech Republic
| | - Roman Čermák
- Faculty of Technology, Department of Polymer Engineering, Tomas Bata University in Zlín, nám. T. G. Masaryka 275, 762 72 Zlín, Czech Republic
| | - Miroslav Raab
- Institute of Macromolecular Chemistry, AS CR, v. v. i., Heyrovského nám. 2, 162 06 Prague, Czech Republic
| | - Martin Obadal
- Borealis Polyolefine GmbH, St.-Peter-Strasse 25, 4021 Linz, Austria
| |
Collapse
|
9
|
Uchiyama Y, Iwasaki S, Ueoka C, Fukui T, Okamoto K, Yamaguchi M. Molecular orientation and mechanical anisotropy of polypropylene sheet containingN,N′-dicyclohexyl-2,6-naphthalenedicarboxamide. ACTA ACUST UNITED AC 2009. [DOI: 10.1002/polb.21647] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
10
|
Výchopňová J, Čermák R, Obadal M, Raab M, Verney V, Commereuc S. The role of specific nucleation in polypropylene photodegradation. Polym Degrad Stab 2007. [DOI: 10.1016/j.polymdegradstab.2007.07.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
11
|
|
12
|
Obadal M, Čermák R, Raab M, Verney V, Commereuc S, Fraïsse F. Study on photodegradation of injection-moulded β-polypropylenes. Polym Degrad Stab 2006. [DOI: 10.1016/j.polymdegradstab.2005.01.046] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
13
|
Obadal M, Čermák R, Stoklasa K. Tailoring of Three-Phase Crystalline Systems in Isotactic Poly(propylene). Macromol Rapid Commun 2005. [DOI: 10.1002/marc.200500272] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
14
|
|
15
|
|