scholarly journals Erratum to: Thermal Conductivity of Low Density Polyethylene Foams Part I: Comprehensive Study of Theoretical Models

Author(s):  
Rezgar Hasanzadeh ◽  
Taher Azdast ◽  
Ali Doniavi ◽  
Richard Eungkee Lee
2019 ◽  
Vol 28 (4) ◽  
pp. 745-754 ◽  
Author(s):  
Hasanzadeh Rezgar ◽  
Azdast Taher ◽  
Doniavi Ali ◽  
Eungkee Lee Richard

2017 ◽  
Vol 25 (6) ◽  
pp. 447-452
Author(s):  
James K. Carson ◽  
Mohamed Alsowailem

The thermal diffusivities of copper/linear-low-density polyethylene (Cu/LLDPE) composites were measured relative to the thermal diffusivity of pure LLDPE. The relative thermal diffusivities were similar to those obtained for copper/high-density polyethylene composites, but were noticeably different from estimated values derived from thermal conductivity, density and specific heat capacity data for Cu/LLDPE from the literature. The thermal diffusivity of the composite material initially decreased below that of the pure polymer with the addition of a small amount of copper, before increasing above it as more was added. There would appear to be marginal or no benefit from adding less than about 15 to 20% metal by volume to a polymer, since the relative increase in thermal diffusivity only becomes significant for greater volumes.


Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1356 ◽  
Author(s):  
Sandra Paszkiewicz ◽  
Anna Szymczyk ◽  
Agata Zubkiewicz ◽  
Jan Subocz ◽  
Rafal Stanik ◽  
...  

In this work, hybrid filler systems consisting of multi-walled carbon nanotubes (MWCNTs) and nano carbon black (nCB) were incorporated by melt mixing in low-density polyethylene (LDPE). To hybrid systems a mixture of MWCNTs and nCB a mass ratio of 1:1 and 3:1 were used. The purpose was to study if the synergistic effects can be achieved on tensile strength and electrical and thermal conductivity. The dispersion state of carbon nanofillers in the LDPE matrix has been evaluated with scanning electron microscopy. The melting and crystallization behavior of all nanocomposites was not significantly influenced by the nanofillers. It was found that the embedding of both types of carbon nanofillers into the LDPE matrix caused an increase in the value of Young’s modulus. The results of electrical and thermal conductivity were compared to LDPE nanocomposites containing only nCB or only MWCNTs presented in earlier work LDPE/MWCNTs. It was no synergistic effects of nCB in multi-walled CNTs and nCB hybrid nanocomposites regarding mechanical properties, electrical and thermal conductivity, and MWCNTs dispersion. Since LDPE/MWCNTs nanocomposites exhibit higher electrical conductivity than LDPE/MWCNTs + nCB or LDPE/nCB nanocomposites at the same nanofiller loading (wt.%), it confirms our earlier study that MWCNTs are a more efficient conductive nanofiller. The presence of MWCNTs and their concentration in hybrid nanocomposites was mainly responsible for the improvement of their thermal conductivity.


2021 ◽  
Vol 13 (2) ◽  
pp. 168781402199440
Author(s):  
Obiora Nnaemeka Ezenwa ◽  
Echezona Nnaemeka Obika ◽  
Onyemazuwa Andrew Azaka ◽  
Emmanuel Chinagorom Nwadike

This work presents the use as a filler of carbonized breadfruit seed coat and recycled low density polyethylene as the binder in ceiling board manufacturing. The depulped bread fruit seed was carbonized for 2 h at a temperature of 500°C. The experimental design was set up using the Design Expert software. A total of 30 experimental tests were developed for four parameters and three responses. The parameters are carbonized bread fruit seed coat/recycled Low Density Polyethylene mass ratio (filler-binder mass ratio), compaction time, compaction temperature and compaction pressure while the responses are thermal conductivity, thickness swell and water absorption. The models developed have been validated using the Study of Variance (ANOVA). Using the 3D surface map, the influence of the parameters on the responses was studied. The optimization method of the Design Expert program was used to evaluate the optimal level of the parameters that will produce the best possible result from their combination. The result gave optimal values of 16.206% filler/rLDPE, 9.406minutes compaction time, 200°C compaction temperature and 11 MPa compaction pressure, which gave 0.246% Water Absorption, 1.998% Thickness Swell and 2.898 W/M.K Thermal Conductivity.


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