Skip to content
Licensed Unlicensed Requires Authentication Published by De Gruyter July 21, 2016

Coagent Modified Polypropylene Prepared by Reactive Extrusion: A New Look into the Structure-Property Relations of Injection Molded Parts

P. Tiwary , H. Gui , P. L. Ferreira and M. Kontopoulou

Abstract

Peroxide-mediated reactive extrusion of linear isotactic polypropylene (L-PP) was conducted in the presence of trimethylolpropane trimethacrylate (TMPTMA) and triallyl trimesate (TAM) coagents, using a twin screw extruder. The resulting coagent-modified polypropylenes (CM-PP) had higher viscosities and elasticities, as well as increased crystallization temperature compared to PP reacted only with peroxide (DCP-PP). Additionally, deviations from terminal flow, and strain hardening were observed in PP modified with TAM, signifying the presence of long chain branching (LCB). The CM-PP formulations retained the modulus and tensile strength of the parent L-PP, in spite of their lower molar mass and viscosities, whereas their elongation at break and the impact strength were better. This was attributed to the finer spherulitic structure of these materials, and to the disappearance of the skin-core layer in the injection molded specimens.


*Correspondence address, Mail address: Marianna Kontopoulou, Department of Chemical Engineering, Queen's University, Kingston, Ontario K7L 3N6, Canada. E-mail:

References

Azizi, H., Ghasemi, I., “Reactive Extrusion of Polypropylene: Production of Controlled-Rheology Polypropylene (CRPP) by Peroxide-Promoted Degradation”, Polym. Test., 23, 137143 (2004) 10.1016/S0142-9418(03)00072-2Search in Google Scholar

Beck, H., “Heterogeneous Nucleating Agents for Polypropylene Crystallization”, J. Appl. Polym. Sci., 11, 673685 (1967) 10.1002/app.1967.070110505Search in Google Scholar

Borsig, E., Van Duin, M., Gotsis, A. D. and Picchioni, F., “Long Chain Branching on Linear Polypropylene by Solid State Reactions”, Eur. Polym. J., 44, 200212 (2008) 10.1016/j.eurpolymj.2007.10.008Search in Google Scholar

Cao, J., Wang, K., Cao, W., Zhang, Q., Du, R. and Fu, Q., “Combined Effect of Shear and Nucleating Agent on the Multilayered Structure of Injection-Molded Bar of Isotactic Polypropylene”, J. Appl. Polym. Sci., 112, 11041113 (2009) 10.1002/app.29540Search in Google Scholar

Chen, Y.-H., Zhong, G.-J, Wang, Y., Li, Z.-M. and Li, L., “Unusual Tuning of Mechanical Properties of Isotactic Polypropylene Using Counteraction of Shear Flow and B-Nucleating Agent on B-Form Nucleation”, Macromolecules, 42, 43434348 (2009) 10.1021/ma900411fSearch in Google Scholar

Coiai, S., Passaglia, E., Aglietto, M. and Ciardelli, F., “Control of Degradation Reactions during Radical Functionalization of Polypropylene in the Melt”, Macromolecules, 37, 84148423 (2004) 10.1021/ma0400315Search in Google Scholar

El Mabrouk, K., Parent, J. S., Chaudhary, B. I. and Cong, R., “Chemical Modification of PP Architecture: Strategies for Introducing Long-Chain Branching”, Polymer, 50, 53905397 (2009) 10.1016/j.polymer.2009.09.066Search in Google Scholar

Feng, Y., Jin, X. and Hay, J. N., “Effect of Nucleating Agent Addition on Crystallization of Isotactic Polypropylene”, J. Appl. Polym. Sci., 69, 20892095 (1998) 10.1002/(SICI)1097-4628(19980906)69:10<2089::AID-APP20>3.0.CO;2-WSearch in Google Scholar

Gahleitner, M., Bachner, C. and Ratajski, E., Rohaczek, G. and Neißl, W., “Effects of the Catalyst System on the Crystallization of Polypropylene”, J. Appl. Polym. Sci., 73, 25072515 (1999) 10.1002/(SICI)1097-4628(19990919)73:12<2507::AID-APP19>3.0.CO;2-VSearch in Google Scholar

Gahleitner, M., Wolfschwenger, J., Bachner, C., Bernreitner, K. and Neißl, W., “Crystallinity and Mechanical Properties of PP-Homopolymers as Influenced by Molecular Structure and Nucleation”, J. Appl. Polym. Sci., 61, 649657 (1996) 10.1002/(SICI)1097-4628(19960725)61:4<649::AID-APP8>3.0.CO;2-LSearch in Google Scholar

Gotsis, A. D., Zeevenhoven, B. L. F. and Hogt, A. H., “The Effect of Long Chain Branching on the Processability of Polypropylene in Thermoforming”, Polym. Eng. Sci., 44, 973982 (2004) 10.1002/pen.20089Search in Google Scholar

Kamal, M. R., Lafleur, P. G., “Heat Transfer in Injection Molding of Crystallizable Polymers”, Polym. Eng. Sci., 24, 692697 (1984) 10.1002/pen.760240911Search in Google Scholar

Kamal, M. R., Moy, F. H., “Microstructural Characterization of Injection-Molded Articles”, J. Appl. Polym. Sci., 28, 17871804 (1983) 10.1002/app.1983.070280521Search in Google Scholar

Kantz, M. R., Newman, H. D. and Stigale, F. H., “The Skin-Core Morphology and Structureproperty Relationships in Injection-Molded Polypropylene”, J. Appl. Polym. Sci., 16, 12491260 (1972) 10.1002/app.1972.070160516Search in Google Scholar

Kim, B. K., Kim, K. J., “Cross-Linking of Polypropylene by Peroxide and Multifunctional Monomer during Reactive Extrusion”, Adv. Polym. Tech., 12, 263269 (1993) 10.1002/adv.1993.060120304Search in Google Scholar

Macosko, C. W.: Rheology: Principles, Measurements, and Applications. John Wiley and Sons, New York (1994)Search in Google Scholar

Mai, F., Wang, K. and Yao, M., Deng, H., Chen, F. and Fu, Q., “Superior Reinforcement in Melt-Spun Polyethylene/Multiwalled Carbon Nanotube Fiber through Formation of a Shish-Kebab Structure”, J. Phys. Chem. B, 114, 10693702 (2010) 10.1021/jp1019944Search in Google Scholar PubMed

Manero, F., Kamal, M. R, Lai-Fook, R. A., Varela, A. E. and Patterson, W. I., “Measurement and Prediction of Temperature Distribution in an Injection Molding Cavity”, Int. Polym. Proc., 18, 185193 (2003) 10.3139/217.1728Search in Google Scholar

Mccallum, T. J., Kontopoulou, M., Park, C. B., Wong, A. and Kim, S. G., “Effect of Branched PP Content on the Physical Properties and Cell Growth during Foaming of TPOs”, J. Appl. Polym. Sci., 110, 817824 (2008) 10.1002/app.28648Search in Google Scholar

Mousavi-Saghandikolaei, S. A, Frounchi, M., Dadbin, S., Augier, S., Passaglia, E. and Ciardelli, F., “Modification of Isotactic Polypropylene by the Free-Radical Grafting of 1,1,1-Trimethylolpropane Trimethacrylate”, J. Appl. Polym. Sci., 104, 950958 (2007) 10.1002/app.25796Search in Google Scholar

Nam, G. J., Yoo, J. H. and Lee, J. W., “Effect of Long-Chain Branches of Polypropylene on Rheological Properties and Foam-Extrusion Performances”, J. Appl. Polym. Sci., 96, 17931800 (2005) 10.1002/app.21619Search in Google Scholar

Parent, J. S., Bodsworth, A., Sengupta, S. S., Kontopoulou, M., Chaudhary, B. I., Poche, D. and Cousteaux, S., “Structure-Rheology Relationships of Long-Chain Branched Polypropylene: Comparative Analysis of Acrylic and Allylic Coagent Chemistry”, Polymer, 50, 8594 (2009) 10.1016/j.polymer.2008.11.014Search in Google Scholar

Passaglia, E., Coiai, S. and Augier, S., “Control of Macromolecular Architecture during the Reactive Functionalization in the Melt of Olefin Polymers”, Prog. Polym. Sci., 34, 911947 (2009) 10.1016/j.progpolymsci.2009.04.008Search in Google Scholar

Patil, N., Invigorito, C., Gahleitner, M. and Rastogi, S., “Influence of a Particulate Nucleating Agent on the Quiescent and Flow-Induced Crystallization of Isotactic Polypropylene”, Polymer, 54, 58835891 (2013) 10.1016/j.polymer.2013.08.004Search in Google Scholar

Pukanszky, B., Mudra, I. and Staniek, P., “Relation of Crystalline Structure and Mechanical Properties of Nucleated Polypropylene”, J. Vinyl. Add. Tech., 3, 5357 (1997) 10.1002/vnl.10165Search in Google Scholar

Ryu, S. H., Gogos, C. G. and Xanthos, M., “Melting Behaviour of Controlled Rheology Polypropylene”, Polymer, 32, 24492455 (1991) 10.1016/0032-3861(91)90088-ZSearch in Google Scholar

Sentmanat, M., Muliawan, E. B. and Hatzikiriakos, S. G., “Fingerprinting the Processing Behavior of Polyethylenes from Transient Extensional Flow and Peel Experiments in the Melt State”, Rheol. Acta, 44, 115 (2004) 10.1007/s00397-004-0398-zSearch in Google Scholar

Spitael, P., Macosko, C. W., “Strain Hardening in Polypropylenes and its Role in Extrusion Foaming”, Polym. Eng. Sci., 44, 20902100 (2004) 10.1002/pen.20214Search in Google Scholar

Supe, A., Graebling, D., “Synthesis of Branched Polypropylene by a Reactive Extrusion Process”, Macromolecules, 35, 46024610 (2002) 10.1021/ma0109469Search in Google Scholar

Tan, V., Kamal, M. R., “Morphological Zones and Orientation in Injection-Molded Polyethylene”, J. Appl. Polym. Sci., 22, 23412355 (1978) 10.1002/app.1978.070220824Search in Google Scholar

Tian, J., Yu, W. and Zhou, C., “Crystallization Behaviors of Linear and Long Chain Branched Polypropylene”, J. Appl. Polym. Sci., 104, 35923600 (2007) 10.1002/app.26024Search in Google Scholar

Tzoganakis, C., Vlachopoulos, J. and Hamielec, A. E., “Production of Controlled-Rheology Polypropylene Resins by Peroxide Promoted Degradation during Extrusion”, Polym. Eng. Sci., 28, 170180 (1988) 10.1002/pen.760280308Search in Google Scholar

Wang, Y., Ni, Q., Liu, Z., Zou, J. and Zhu, X., “Grafting Modification and Properties of Polypropylene with Pentaerythritol Tetra-Acrylate”, J. Polym. Res., 18, 21852193 (2010) 10.1007/s10965-011-9629-zSearch in Google Scholar

Wenig, W., Herzog, F., “Injection Molding of Polypropylene: X-Ray Investigation of the Skin-Core Morphology”, J. Appl. Polym. Sci., 50, 21632171 (1993) 10.1002/app.1993.070501216Search in Google Scholar

Wu, W., Parent, J. S., Sengupta, S. S. and Chaudhary, B. I., “Preparation of Crosslinked Microspheres and Porous Solids from Hydrocarbon Solutions: A New Variation of Precipitation Polymerization Chemistry”, J. Polym. Sci., Part A: Polym. Chem., 47, 65616570 (2009) 10.1002/pola.23699Search in Google Scholar

Zhang, Y., Tiwary, P., Parent, J. S. and Park, C. B., “Crystallization and Foaming of Coagent-Modified Polypropylene: Nucleation Effects of Cross-Linked Nanoparticles”, Polymer, 54, 48144819 (2013) 10.1016/j.polymer.2013.07.020Search in Google Scholar

Zhang, Y., Tiwary, P., Gui, H., Kontopoulou, M. and Parent, J. S., “Crystallization of Coagent-Modified Polypropylene: Effect of Polymer Architecture and Cross-Linked Nanoparticles”, Ind. Eng. Chem. Res., 53, 1592315931 (2014) 10.1021/ie5027277Search in Google Scholar

Zhang, Y., Parent, J. S., Kontopoulou, M. and Park, C. B., “Foaming of Reactively Modified Polypropylene: Effects of Rheology and Coagent Type”, J. Cell. Plast., 51, 505522 (2015) 10.1177/0021955X14566209Search in Google Scholar

Zhao, W., Huang, Y., Liao, X. and Yang, Q., “The Molecular Structure Characteristics of Long Chain Branched Polypropylene and its Effects on Non-Isothermal Crystallization and Mechanical Properties”, Polymer, 54, 14551462 (2013) 10.1016/j.polymer.2012.12.073Search in Google Scholar

Received: 2015-11-16
Accepted: 2016-04-16
Published Online: 2016-07-21
Published in Print: 2016-08-12

© 2016, Carl Hanser Verlag, Munich

Downloaded on 1.2.2023 from https://www.degruyter.com/document/doi/10.3139/217.3209/html
Scroll Up Arrow