Submitted Successfully!
To reward your contribution, here is a gift for you: A free trial for our video production service.
Thank you for your contribution! You can also upload a video entry or images related to this topic.
Version Summary Created by Modification Content Size Created at Operation
1
Ana Pilipovic
 -- 1266 2023-12-08 13:15:58 |
2 update references and layout
Rita Xu
 Meta information modification 1266 2023-12-11 04:02:57 |

Video Upload Options

Do you have a full video?
Send video materials Upload full video

Confirm

Are you sure to Delete?
Yes No
Cite
If you have any further questions, please contact Encyclopedia Editorial Office.
Travaš, L.; Rujnić Havstad, M.; Pilipović, A.; Pilipovic, A. High-Density Polyethylene. Encyclopedia. Available online: https://encyclopedia.pub/entry/52528 (accessed on 05 July 2024).
Travaš L, Rujnić Havstad M, Pilipović A, Pilipovic A. High-Density Polyethylene. Encyclopedia. Available at: https://encyclopedia.pub/entry/52528. Accessed July 05, 2024.
Travaš, Lovro, Maja Rujnić Havstad, Ana Pilipović, Ana Pilipovic. "High-Density Polyethylene" Encyclopedia, https://encyclopedia.pub/entry/52528 (accessed July 05, 2024).
Travaš, L., Rujnić Havstad, M., Pilipović, A., & Pilipovic, A. (2023, December 08). High-Density Polyethylene. In Encyclopedia. https://encyclopedia.pub/entry/52528
Travaš, Lovro, et al. "High-Density Polyethylene." Encyclopedia. Web. 08 December, 2023.
High-Density Polyethylene
Edit
This entry is adapted from the peer-reviewed paper 10.3390/polym15173645

Due to its mechanical, rheological, and chemical properties, high-density polyethylene (HDPE) is commonly used as a material for producing the pipes for transport of various media. Low thermal conductivity (0.4 W/mK) narrows down the usage of HDPE in the heat exchanger systems.

boron nitride composite expanded graphite HDPE pipe thermal conductivity

1. Background

Nanocomposites are composites made of particles up to 100 nm large, while microcomposites contain particles sized from 0.1 to 100 µm. Generally, there is a significant effect on the mechanical and rheological properties of the composite caused by micro- and nano-constituents compared to the matrix material. Nanocomposites based on polymer matrix and non-polymer additives are the subject of various studies aiming for the enhancement of electric conductivity, antistatic features, tensile strength, flexural strength, water absorption, abrasion resistivity, etc. [1][2][3][4][5][6]. Due to the significantly higher thermal conductivity (λ) of carbon-based additives compared to polymers, the presence of these additives results in the increase of thermal conductivity of carbon–polymer composites [7]. The enhanced thermal properties of graphite are related to its structure, in which atoms of carbon build a hexagonal one-layered structure. Expanded graphite (EG) is one of the many modifications of graphite, which is produced by intercalation and can be exfoliated several hundred times compared to the original volume when exposed to heat. Three-dimensional wormlike structures of EG are the basis for achieving increased values of electro and thermal conductivity in EG–polymer composite [8]. Compared to polymers, most metals have a hundred times higher λ values. Some metal additives used in polymer matrices, such as nickel–copper alloy and titanium, are characterized by excellent chemical resistivity and can therefore be used as heat exchangers in media such as sea water or chemicals. On the other hand, polymer processing demands significantly lower temperatures (<300 °C) compared to metal processing [9]. Polyethylene, especially high-density polyethylene (HDPE), due to its low price, recyclability, nontoxicity, corrosion resistivity, and good processing properties, has a wide range of applications. Features of composites with HDPE as matrix are based on the interphase compatibility between matrix and additive, polarity between the contact surfaces of the matrix and additive, etc. The dispersion of additives in the matrix depends on size, shape, dispersion technique, equipment, and on processing parameters (time, temperature, etc.). To increase the dispersion of additive in matrix, and thus reduce the surface tension between components, various methods are applied. Some of them include the addition of maleic anhydride (MAH), resulting in an increase of strength, toughness, and ductility. Other methods include high speed shearing during the mixing of components (such as poly(methyl-methacrylate) and EG), resulting in similar improvements compared to MAH [10].

2. Composites with HDPE and EG

Sobaliček et al. exposed HDPE and untreated EG mixture to a temperature above the melting point of HDPE, which resulted in multiple times higher value of thermal conductivity compared to HDPE [11]. EG treated with poly(vinyl-alcohol) shows an increase of thermal conductivity in the polymer, even at low percentages of additives, which was researched by Yin et al. [12]. According to Panagiotis et al., the polystyrene (PS) matrix, compared to the HDPE matrix with EG additive, results in a multiple-fold increase in thermal conductivity [13]. A similar procedure and parameters were applied (temperature of kneader chamber of 185 °C, at 60 rpm/min, and for 10 min) for mixing HDPE/EG/carbon nano tubes (CNT) composite, with EG up to 20 wt.% and CNT up to 3 wt.%. It was then pressed at a temperature of 185 °C and pressure of 10 MPa. For the highest concentration of both additives, thermal conductivity reached a value of ~ 3 W/mK [14]. In their research, Sanchez et al. produced a composite with an ultra-high molecular weight polyethylene (UHMWPE) matrix and graphite as an additive by ultrasonic injection molding. Even at low mass percentage (7 wt.%), the tensile modulus of the composite increased 96% when compared to the tensile modulus of the matrix [15]. Abdelrazeq et al. researched the properties of a phase-change material made of HDPE matrix, paraffin wax, and 15 wt.% EG. The composite was exposed to UV radiation, temperature, and moisture. The highest value of thermal conductivity, 1.64 W/mK, was measured at the highest mass percentage of EG [16].

3. Composites with HDPE and BN

Muratov et al. used HDPE and hexagonal BN (hBN) with two particle sizes, 10 μm in mass proportions of 25% and 50% and 150 nm in 25 wt.%. The highest value of thermal conductivity, 2.08 W/mK, was achieved in the composite with 50 wt.% micro-sized hBN particles and without a compatibilizer. The yield strength for all composites reached between 22 MPa and 24.9 MPa, while the highest tensile modulus, 3829 MPa, was measured for the composite with 50 wt.% mass percentages of hBN micro particles and compatibilizer based on titanate (KR TTS) [17]. A composite with LDPE matrix and hexagonal boron nitride nanosheets (hBNNs) was studied by Ali et al., where hBNNs were added in a volume percentage up to 30%. A value of thermal conductivity of 1.46 W/mK was reached for the highest volume proportion of additive. The elasticity modulus reached 2.2 GPa for 25 vol.% and the tensile strength was 18.7 MPa for the same volume percentage of the additive [18]. A layered structure of LDPE/HDPE and BN composite was researched by Shang et al. BN was added in composites in 15 wt.%, which resulted in a measured thermal conductivity of 3.54 W/mK for the layered structure and 3.13 W/mK for the randomly oriented composite with the same mass percentage of BN [19]. A significant increase in thermal conductivity was achieved by Zhang et al. by stretching composite foil with HDPE matrix and boron nitride nanoplates (BNNPs) as additives. The measured thermal conductivity reached 3.1 W/mK for unstretched foil with 15 wt.% BNNP, while for stretched foil (with stretching ratio Λ = 5), thermal conductivity reached 106.2 W/mK [20]. A recycled PE matrix with high ratio of aluminum oxide and zinc oxide as matrix and BN as additive was used by Rasul et al. to produce the composite, where silane was used as a compatibilizer. The thermal conductivity of the matrix was 0.72 W/mK; for the composite with 5 wt.% of BN, it increased to 0.84 W/mK and for the composite with 5 wt.% of BN and 3 wt.% of silane, it reached 0.96 W/mK [21]. An increase of a composite’s thermal conductivity was achieved by Shi et al. by solid-state extrusion. Using UHMWPE as the matrix and BN as an additive with 50 wt.%, it reached a thermal conductivity of 23.03 W/mK [22]. In his research, Lebedev compared the thermal conductivity of two composites produced by injection molding. The thermal conductivity of the composite made of polyacrylic acid (PLA) and BN reached 0.67 W/mK, while the composite made of LDPE and BN reached a thermal conductivity of 0.7 W/mK for the same BN ratio of 40 wt.% [23]. Güzdemir et al. researched the increase of thermal conductivity for LDPE/BN composite in the shape of extruded film. The initial thermal conductivity of the LDPE matrix of 0.4 W/mK increased to 1.8 W/mK for the composite with 30 vol% of BN additive [24]. Other research, such as the study conducted by Yang et al., included a composite with HDPE matrix with BN (25 wt.%) and coconut shell carbon (3 wt.%), reaching a thermal conductivity of 0.943 W/mK [25].
Considering the superior thermal conductivity inherent in both BN and EG compared to PE, it is foreseeable that the EG/BN/HDPE composite will exhibit significantly higher thermal conductivity in comparison to HDPE. While this particular composite has not yet been explored, the hypothesis suggests a substantial multiple-fold increase in thermal conductivity. The potential application of such a material would primarily target heat exchangers, an area where mechanical properties carry equal significance alongside thermal attributes. Consequently, the composite material will undergo testing to assess its tensile properties, providing valuable insights into its suitability for this purpose.

References

  1. Alshammari, B.A.; Al-Mubaddel, F.S.; Karim, M.R.; Hossain, M.; Al-Mutairi, A.S.; Wilkinson, A.N. Addition of Graphite Filler to Enhance Electrical, Morphological, Thermal, and Mechanical Properties in Poly (Ethylene Terephthalate): Experimental Characterization and Material Modeling. Polymers 2019, 11, 1411.
  2. Imiolek, P.; Kasprowicz, K.; Laska, J. Antistatic polyethylene free-standing films modified with expanded graphite—Technological aspects. Polimery 2020, 65, 275–279.
  3. Bazan, P.; Mierzwiński, D.; Bogucki, R.; Kuciel, S. Bio-Based Polyethylene Composites with Natural Fiber: Mechanical, Thermal, and Ageing Properties. Materials 2020, 13, 2595.
  4. Makhlouf, A.; Belaadi, A.; Amroune, S.; Bourchak, M.; Satha, H. Elaboration and Characterization of Flax Fiber Reinforced High Density Polyethylene Biocomposite: Effect of the Heating Rate on Thermo-mechanical Properties. J. Nat. Fibers 2022, 19, 3928–3941.
  5. Zhang, Q.; Zhang, D.; Xu, H.; Lu, W.; Ren, X.; Cai, H.; Lei, H.; Huo, E.; Zhao, Y.; Qian, M.; et al. Biochar filled high-density polyethylene composites with excellent properties: Towards maximizing the utilization of agricultural wastes. Ind. Crop. Prod. 2020, 146, 112185.
  6. Eze, I.O.; Igwe, I.O.; Ogbobe, O.; Obasi, H.C.; Ezeamaku, U.L.; Nwanonenyi, S.C.; Anyanwu, E.E.; Nwachukwu, I. Effects of Compatibilization on Mechanical Properties of Pineapple Leaf Powder Filled High Density Polyethylene. Int. J. Eng. Technol. 2017, 10, 22–28.
  7. Wieme, T.; Duan, L.; Mys, N.; Cardon, L.; D’hooge, D.R. Effect of Matrix and Graphite Filler on Thermal Conductivity of Industrially Feasible Injection Molded Thermoplastic Composites. Polymers 2019, 11, 87.
  8. Wei, B.; Zhang, L.; Yang, S. Polymer composites with expanded graphite network with superior thermal conductivity and electromagnetic interference shielding performance. Chem. Eng. J. 2021, 404, 126437.
  9. Chen, X.; Su, Y.; Reay, D.; Riffat, S. Recent research developments in polymer heat exchangers—A review. Renew. Sustain. Energy Rev. 2016, 60, 1367–1386.
  10. Wang, Y.; Lu, L.; Hao, Y.; Wu, Y.; Li, Y. Mechanical and Processing Enhancement of a Recycled HDPE/PPR-Based Double-Wall Corrugated Pipe via a POE-g-MAH/CaCO3/HDPE Polymer Composite. ACS Omega 2021, 6, 19705–19716.
  11. Sobolčiak, P.; Abdulgader, A.; Mrlik, M.; Popelka, A.; Abdala, A.A.; Aboukhlewa, A.A.; Karkri, M.; Kiepfer, H.; Bart, H.-J.; Krupa, I. Thermally Conductive Polyethylene/Expanded Graphite Composites as Heat Transfer Surface: Mechanical, Thermo-Physical and Surface Behavior. Polymers 2020, 12, 2863.
  12. Yin, X.; Jie, X.; Wei, K.; He, G.; Feng, Y. In-situ exfoliation and thermal conductivity in phase-transition-assisted melt blending fabrication of low-density polyethylene/expanded graphite nanocomposite. Polym. Eng. Sci. 2022, 62, 3487–3497.
  13. Klonos, P.A.; Papadopoulos, L.; Kourtidou, D.; Chrissafis, K.; Peoglos, V.; Kyritsis, A.; Bikiaris, D.N. Effects of Expandable Graphite at Moderate and Heavy Loadings on the Thermal and Electrical Conductivity of Amorphous Polystyrene and Semicrystalline High-Density Polyethylene. Appl. Nano 2021, 2, 31–45.
  14. Che, J.; Wu, K.; Lin, Y.; Wang, K.; Fu, Q. Largely improved thermal conductivity of HDPE/expanded graphite/carbon nanotubes ternary composites via additive network-network synergy. Compos. Part A Appl. Sci. Manuf. 2017, 99, 32–40.
  15. Sánchez-Sánchez, X.; Elias-Zuñiga, A.; Hernández-Avila, M. Processing of ultra-high molecular weight polyethylene/graphite composites by ultrasonic injection moulding: Taguchi optimization. Ultrason. Sonochemistry 2018, 44, 350–358.
  16. Abdelrazeq, H.; Sobolčiak, P.; Al-Maadeed, M.A.-A.; Ouederni, M.; Krupa, I. Recycled Polyethylene/Paraffin Wax/Expanded Graphite Based Heat Absorbers for Thermal Energy Storage: An Artificial Aging Study. Molecules 2019, 24, 1217.
  17. Muratov, D.S.; Stepashkin, A.A.; Anshin, S.M.; Kuznetsov, D.V. Controlling thermal conductivity of high density polyethylene filled with modified hexagonal boron nitride (hBN). J. Alloys Compd. 2018, 735, 1200–1205.
  18. Ali, M.; Abdala, A. Large scale synthesis of hexagonal boron nitride nanosheets and their use in thermally conductive polyethylene nanocomposites. Int. J. Energy Res. 2022, 46, 10143–10156.
  19. Shang, Y.; Yang, G.; Su, F.; Feng, Y.; Ji, Y.; Liu, D.; Yin, R.; Liu, C.; Shen, C. Multilayer polyethylene/ hexagonal boron nitride composites showing high neutron shielding efficiency and thermal conductivity. Compos. Commun. 2020, 19, 147–153.
  20. Zhang, R.-C.; Huang, Z.; Huang, Z.; Zhong, M.; Zang, D.; Lu, A.; Lin, Y.; Millar, B.; Garet, G.; Turner, J.; et al. Uniaxially stretched polyethylene/boron nitride nanocomposite films with metal-like thermal conductivity. Compos. Sci. Technol. 2020, 196, 108154.
  21. Rasul, G.; Kiziltas, A.; Bin Hoque, S.; Banik, A.; Hopkins, P.E.; Tan, K.-T.; Arfaei, B.; Shahbazian-Yassar, R. Improvement of the thermal conductivity and tribological properties of polyethylene by incorporating functionalized boron nitride nanosheets. Tribol. Int. 2022, 165, 107277.
  22. Shi, A.; Li, Y.; Liu, W.; Xu, J.-Z.; Yan, D.-X.; Lei, J.; Li, Z.-M. Highly thermally conductive and mechanically robust composite of linear ultrahigh molecular weight polyethylene and boron nitride via constructing nacre-like structure. Compos. Sci. Technol. 2019, 184, 107858.
  23. Lebedev, S.M. A comparative study on thermal conductivity and permittivity of composites based on linear low-density polyethylene and poly(lactic acid) filled with hexagonal boron nitride. Polym. Compos. 2021, 43, 111–117.
  24. Güzdemir; Kanhere, S.; Bermudez, V.; Ogale, A.A. Boron Nitride-Filled Linear Low-Density Polyethylene for Enhanced Thermal Transport: Continuous Extrusion of Micro-Textured Films. Polymers 2021, 13, 3393.
  25. Yang, X.; Song, X.; Hu, Z.; Li, C.; Guo, T. Improving comprehensive properties of high-density polyethylene matrix composite by boron nitride/coconut shell carbon reinforcement. Polym. Test. 2022, 115, 107728.
More
© Text is available under the terms and conditions of the Creative Commons Attribution (CC BY) license; additional terms may apply. By using this site, you agree to the Terms and Conditions and Privacy Policy.
Upload a video for this entry
Information
Subjects: Engineering, Manufacturing
Contributors MDPI registered users' name will be linked to their SciProfiles pages. To register with us, please refer to https://encyclopedia.pub/register :
Lovro Travaš
,
Maja Rujnić Havstad
,
Ana Pilipović
,
Ana Pilipovic
View Times: 189
Revisions: 2 times (View History)
Update Date: 11 Dec 2023
Table of Contents
    1000/1000
    Hot Most Recent
    Video Production Service
    Feedback