اثر ریزساختار بر خواص رئولوژیکی پلی‌اتیلن‌های خطی و شاخه‌دار

نوع مقاله : تالیفی

نویسندگان

1 پژوهشگاه پلیمر و پتروشیمی

2 عضو هیات علمی پژوهشکده مهندسی پژوهشگاه پلیمر وپتروشیمی ایران

3 دانشگاه صنعتی امیر کبیر

4 دانشگاه تحصیلات تکمیلی علوم پایه زنجان،

چکیده

در دهه ­های اخیر، ریزساختارهای پلیمرها و مهندسی ساختار مولکولی آن­ها به­ دلیل آثار شگرف آن­ها بر خواص نهایی پلیمرها بسیار مورد توجه هستند. با افزایش تقاضای مصرف پلیمرها، معرفی انواع جدید آن­ها با استفاده از تغییر ریزساختار و درنتیجه بهبود خواص، اهمیت ویژه‌ای یافته است. پلی­ اتیلن رزین تجاری و پرمصرفی در صنعت است که ساختار مولکولی متنوع و خواص گران­روکشسانی، مکانیکی، گرمایی و فرایندی مختلف دارد. بررسی اثر ریزساختار بر پاسخ گران­روکشسانی پلی‌اتیلن‌ها می‌تواند پیش­بینی بسیار خوبی از رفتار فراوری و مسائل مرتبط با آن ارائه دهد. این مسئله، دستیابی به هدف مدنظر را برای مهندسان با صرف زمان و انرژی کمتری امکان­پذیر می­ سازد. به ­طور کلی، وجود شاخه ­های بلند در ساختار پلی­ اتیلن باعث بهبود استحکام و کشسانی مذاب می‌شود. تاکنون روش‌های متنوعی برای کنترل معماری مولکولی پلی ­اتیلن‌های مختلف ارائه شده است که از مهم­ترین آن­ ها می ­توان به پلیمرشدن و استفاده از کاتالیزگرهای فضاویژه، تابش پرانرژی و اصلاح مذاب واکنشی اشاره کرد. در این مقاله، اثر ریزساختار پلی­ اتیلن‌های شاخه ­دار و خطی بر خواص رئولوژیکی و پژوهش ­های انجام­ گرفته در این زمینه مرور شده است.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Effect of Microstructure on Rheological Behavior of Linear- and Branched-Polyethylene

نویسندگان [English]

  • mohammadreza jozaghkar 1
  • Hassan Arabi 2
  • Fatemeh Heydari 3
  • Mahnaz Hasanpour 4
1 Iran polymer and petrochemical institute
2 Academic staff of engineering faculty of Iran Polymer and Petrochemical Institute
3 Amirkabir University of Technology
4 Institute for Advanced Studies in Basic Sciences (IASBS), P.O. Box 45137-66731, Zanjan, Iran
چکیده [English]

In recent decades, the microstructure of polymers and their molecular structure engineering are of great interest due to their tremendous effects on the final properties of polymers. With the increasing demand of polymers, introducing new types of them by changing the microstructure and as a result improving the properties has become particularly important. Polyethylene is a commercial and widely used resin in the industry, which has a diverse molecular structure and consequently, various viscoelastic, mechanical, thermal, and processing properties. Investigating the effect of microstructure on the viscoelastic response of polyethylenes can provide a very good prediction of the processing behavior and related issues; which makes it possible for engineers to achieve the desired goal by spending less time and energy. In general, the presence of long chain branches in the structure of polyethylene improves the melt strength and elasticity. So far, various methods have been presented to control the molecular architecture of different polyethylenes, the most important of which are polymerization and the use of specific catalysts, high-energy radiation, and reactive melt modification. In this article, the microstructure effect of linear- and branched-polyethylenes on the rheological properties and the research performed in this field are reviewed.

کلیدواژه‌ها [English]

  • microstructure
  • polyethylene
  • non-linear rheological behavior
  • long chain branching
  • processability

مراجع

  1. Moradkhani E., Entezam M., Ahmadi M., Khonakdar H.A., Ruckdäschel H., and Altstaedt V., Irradiation Processing to Modify HDPE Molecular Architecture: Correlation with Irradiation Conditions and Polymer Grade, Mater. Today Commun., 31, 2021, 2022.
  2. Jozaghkar M.R., Jahani Y., Arabi H., and Ziaee F., Preparation and Assessment of Phase Morphology, Rheological Properties, and Thermal Behavior of Low-Density Polyethylene/Polyhexene-1 Blends, Polym. Plast. Technol. Eng., 57, 757–765,2018.
  3. Mortazavi S., Ghasemi I., and Oromiehie A., Morphological and Rheological Properties of Low-Density Polyethylene/Thermoplastic Starch Blend: Investigation of the Role of High Elastic Network, J. Vinyl Addit. Technol., 20, 250–259, 2014.
  4. Afzali M., Morshedian J., Moballegh L., and Ahmadi S., Comparing Effects of Two Tri-Block Copolymers on Morphology, Thermal, Mechanical and Rheological Properties of Polystyrene/Low Density Polyethylene Blends, Mater. Res. Express, 5, 085305, 2018.
  5. Jozaghkar M.R., Jahani Y., Arabi H., and Ziaee F., Effect of Polyethylene Molecular Architecture on the Dynamic Viscoelastic Behavior of Polyethylene/Polyhexene-1 Blends and Its Correlation with Morphology, Polym. Technol. Mater., 58, 560–572, 2019.
  6. Jozaghkar M.R., Jalilian S.M., and Ziaee F., Synthesis and Assessment of the Effect of Monomer Feed Ratio and Lewis Acids on Copolymerization of Butyl Methacrylate/1-Octene,

Polyolefin J., 9, 85–91, 2022.

  1. Zarand S.M.G., Shahsavar S., and Jozaghkar M.R., A Kinetic Monte Carlo Simulation of Individual Site Type of Ethylene and α-Olefins Polymerization, J. Korean Chem. Soc., 62, 191–202, 2018.
  2. Entezam M., Abbasi M., and Ahmadi M., Theoretical Correlation of Linear and Non-linear Rheological Symptoms of Long-Chain Branching in Polyethylenes Irradiated by Electron Beam at Relatively Low Doses, Rheol. Acta, 56, 729–742, 2017.
  3. Kolodka E., Wang W.J., Zhu S., and Hamielec A., Rheological and Thermomechanical Properties of Long-Chain-Branched Polyethylene Prepared by Slurry Polymerization with Metallocene Catalysts, J. Appl. Polym. Sci., 92, 307–316, 2004.
  4. Yan D., Wang W., and Zhu S., Effect of Long Chain Branching on Rheological Properties of Metallocene Polyethylene, Polymer, 40, 1737–1744, 1999.
  5. Lamnawar K. and Maazouz A., Rheology and Processing of Polymers, Polymers (Basel)., 14, 1–7, 2022.
  6. Dordinejad A.K., Sharif F., Ebrahimi M., and Rashedi R., Rheological and Thermorheological Assessment of Polyethylene in Multiple Extrusion Process, Thermochim.

Acta, 668, 19–27, 2018.

  1. Wagner M.H., Zheng W., Wang P., Talamante S.R., and Narimissa E., Shear and Elongational Rheology of Photo-oxidative Degraded HDPE and LLDPE, AIP Conf. Proc., 1843, 2017.
  2. Kim Y.C. and Yang K.S., Effect of Peroxide Modification on Melt Fracture of Linear Low Density Polyethylene During Extrusion, Polym. J., 31, 579–584, 1999.
  3. Ronca S., Polyethylene, In Brydson's Plastics Materials, Gilbert M., 8th ed., Butterworth-Heinemann, USA, 247-278, 2017.
  4. Stadler F.J., Kaschta J., Münstedt H., and Becker F., Influence of Molar Mass Distribution and Long-Chain Branching on Strain Hardening of Low Density Polyethylene, 48, 479–490, 2009.
  5. Cuadri A.A. and Martín-Alfonso J.E., The Effect of Thermal and Thermo-oxidative Degradation Conditions on Rheological, Chemical and Thermal Properties of HDPE, Polym. Degrad. Stab., 141, 11–18, 2017.
  6. Cheng S., Phillips E., and Parks L., Improving Processability of Polyethylenes by Radiation-Induced Long Chain Branching, Radiat. Phys. Chem., 78, 563–566, 2009.
  7. Kuhn R. and Krömer H., Structures and Properties of Different Low Density Polyethylenes, Colloid Polym. Sci., 260, 1083–1092, 1982.
  8. Dietrich M.L., Sarmoria C., Brandolin A., and Asteasuain M., Modeling Low-Density Polyethylene (LDPE) Production in Tubular Reactors: Connecting Polymerization Conditions

with Polymer Microstructure and Rheological Behavior, Macromol. React. Eng., 16, 1–63, 2022.

  1. Abbasi M., Golshan Ebrahimi N., and Wilhelm M., Investigation of the Rheological Behavior of Industrial Tubular and Autoclave LDPEs under SAOS, LAOS, Transient Shear, and Elongational Flows Compared with Predictions from the MSF Theory, J. Rheol., 57, 1693–1714, 2013.
  2. Abbasi M., Golshan Ebrahimi N., Nadali M., and Esfahani M.K., Elongational Viscosity of LDPE with Various Structures: Employing A New Evolution Equation in MSF Theory, Rheol. Acta, 51, 163–177, 2012.
  3. Sardashti P., Tzoganakis C., Polak M.A., and Penlidis A., Radiation Induced Long Chain Branching in High-Density Polyethylene through a Reactive Extrusion Process, Macromol.

React. Eng., 8, 100–111, 2014.

  1. Dartora P.C., Santana R.M.C., and Moreira A.C.F., The Influence of Long Chain Branches of LLDPE on Processability and Physical Properties, Polimeros, 25, 531–539, 2015.
  2. McDaniel M.P., Rohlfing D.C., and Benham E.A., Long ChainBranching in Polyethylene from the Phillips Chromium Catalyst, Polym. React. Eng., 11, 101–132, 2003.
  3. Ye Z., Alobaidi F., Zhu S., and Subramanian R., Long-Chain Branching and Rheological Properties of Ethylene-1-Hexene Copolymers Synthesized from Ethylene Stock by Concurrent Tandem Catalysis, Macromol. Chem. Phys., 206, 2096–2105, 2005.
  4. Dickie B.D. and Koopmans R.J., Long-Chain Branching Determination in Irradiated Linear Low Density Polyethylene, J. Polym. Sci. Part C, Polym. Lett., 28, 193–198, 1990.
  5. Cheng S., Dehaye F., Bailly C., Biebuyck J.J., Legras R., and Parks L., Studies on Polyethylene Pellets Modified by Low Dose Radiation Prior to Part Formation, Nucl. Instruments Methods Phys. Res. Sect. B: Beam Interact. Mater. Atoms, 236, 130–136, 2005.
  6. Pinheiro L.A., Chinelatto M.A., and Canevarolo S.V., The Role of Chain Scission and Chain Branching in High Density Polyethylene During Thermo-mechanical Degradation, Polym. Degrad. Stab., 86, 445–453, 2004.
  7. Xie L., Liang X., Huang H., Yang L., Zhang F., Li X., and Luo Z., Preparation and Properties of Long Chain branched High-Density Polyethylene Based on Nano-SiO2 Grafted Glycidyl Methacrylate, RSC Adv., 9, 1123–1133, 2019.

فایل ها

هم رسانی

ارجاع به این مقاله

آمار