PMID- 37688271
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20230911
IS  - 2073-4360 (Electronic)
IS  - 2073-4360 (Linking)
VI  - 15
IP  - 17
DP  - 2023 Sep 4
TI  - Optimization of Thermal Conductivity and Tensile Properties of High-Density 
      Polyethylene by Addition of Expanded Graphite and Boron Nitride.
LID - 10.3390/polym15173645 [doi]
LID - 3645
AB  - 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. The main goal of the work is to 
      reduce the vertical depth of the HDPE pipe buried in the borehole by increasing 
      the thermal conductivity of the material. This property can be improved by adding 
      certain additives to the pure HDPE matrix. Composites made of HDPE with metallic 
      and non-metallic additives show increased thermal conductivity several times 
      compared to the thermal conductivity of pure HDPE. Those additives affect the 
      mechanical properties too, by enhancing or degrading them. In this research, the 
      thermal conductivity and tensile properties of composite made of HDPE matrix and 
      two types of additives, expanded graphite (EG) and boron nitride (BN), were 
      tested. Micro-sized particles of EG and two different sizes of BN particles, 
      micro and nano, were used to produce composite. The objective behind utilizing 
      composite materials featuring dual additives is twofold: firstly, to enhance 
      thermal properties, and secondly, to improve mechanical properties when compared 
      with the pure HDPE. As anticipated, the thermal conductivity of the composites 
      exhibited an eightfold rise in comparison to the pure HDPE. The tensile modulus 
      experienced augmentation across all variations of additive ratios within the 
      composites, albeit with a marginal reduction in tensile strength. This implies 
      that the composite retains a value similar to pure HDPE in terms of tensile 
      strength. Apart from the enhancement observed in all the aforementioned 
      properties, the most significant downside of these composites pertains to their 
      strain at yield, which experienced a reduction, declining from the initial 8.5% 
      found in pure HDPE to a range spanning from 6.6% to 1.8%, dependent upon the 
      specific additive ratios and the size of the BN particles.
FAU - Travas, Lovro
AU  - Travas L
AD  - Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, 
      Ivana Lucica 5, 10000 Zagreb, Croatia.
FAU - Rujnic Havstad, Maja
AU  - Rujnic Havstad M
AUID- ORCID: 0000-0002-0700-9388
AD  - Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, 
      Ivana Lucica 5, 10000 Zagreb, Croatia.
FAU - Pilipovic, Ana
AU  - Pilipovic A
AUID- ORCID: 0000-0003-1330-6458
AD  - Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, 
      Ivana Lucica 5, 10000 Zagreb, Croatia.
LA  - eng
GR  - KK.01.2.1.02/Competitiveness and Cohesion 2014-2020/
PT  - Journal Article
DEP - 20230904
PL  - Switzerland
TA  - Polymers (Basel)
JT  - Polymers
JID - 101545357
PMC - PMC10489680
OTO - NOTNLM
OT  - HDPE pipe
OT  - boron nitride
OT  - composite
OT  - expanded graphite
OT  - tensile properties
OT  - thermal conductivity
COIS- The authors declare no conflict of interest.
EDAT- 2023/09/09 11:46
MHDA- 2023/09/09 11:47
PMCR- 2023/09/04
CRDT- 2023/09/09 01:25
PHST- 2023/08/08 00:00 [received]
PHST- 2023/08/27 00:00 [revised]
PHST- 2023/08/30 00:00 [accepted]
PHST- 2023/09/09 11:47 [medline]
PHST- 2023/09/09 11:46 [pubmed]
PHST- 2023/09/09 01:25 [entrez]
PHST- 2023/09/04 00:00 [pmc-release]
AID - polym15173645 [pii]
AID - polymers-15-03645 [pii]
AID - 10.3390/polym15173645 [doi]
PST - epublish
SO  - Polymers (Basel). 2023 Sep 4;15(17):3645. doi: 10.3390/polym15173645.