Solar reflectance, surface adhesion, and thermal conductivity of wood/natural rubber composite sheet with Tio2/polyurethane topcoat for roofing applications

2012 ◽  
Vol 18 (3) ◽  
pp. 184-191 ◽  
Author(s):  
Natita Hamaviriyapornwattana ◽  
Narongrit Sombatsompop ◽  
Teerasak Markpin ◽  
Apisit Kositchaiyong ◽  
Ekachai Wimolmala
2020 ◽  
Vol 987 ◽  
pp. 47-52
Author(s):  
Wasan Leelawanachai ◽  
Nattapol Dedruktip ◽  
Nuchnapa Tangboriboon

Natural rubber is an elastomeric material to make rubber products such as toys, households, automobiles, wheel tires, medical and health care products. Natural rubber compound is one kind of polymer matrix composites (PMCs) composed of natural rubber compound acted as a matrix phase and filler acted as a dispersed or reinforcement phase. There are many kinds of fillers used in the PMCs in terms of particles, fibers, and structural sheets. Adding organic/inorganic fibers into the natural rubber composites can increase the mechanical-thermal-physical properties and sound absorption. The natural rubber embedded fiber composite samples were prepared via the vulcanization process at the curing temperature 150°C by the two-roll mill. The amount of whisker alumina (Al2O3), coconut coir and water hyacinth fiber were varied from 0 to 50 phr on 100 phr of natural rubber in a sulfur curing system. The obtained rubber composite samples were of good mechanical properties, low thermal conductivity and good acoustic-sound absorption, suitable for various applications such as automobile, insulation and storage tank. The obtained rubber composite with 10 phr whisker alumina added (NR-Al-10) possessed the tensile strength, Young’s modulus, elongation at break and thermal conductivity values equal to 14.38 ± 1.95 MPa, 545.63 ± 25.67 MPa, 1038.4 ± 41.45% and 0.02527 ± 0.0003 W/m.K, respectively. Furthermore, the sound absorption value of natural rubber composite added 10 phr whisker alumina (NR-Al-10) is equal to 45.09% in the range of 3000‒4000 Hz of acoustic sound level better than the pure natural compound without adding filler.


2013 ◽  
Vol 12 (03) ◽  
pp. 1350011 ◽  
Author(s):  
YAN HE ◽  
YUANZHENG TANG

Classical molecular dynamics (MD) simulations are employed to study the thermal conductivity of carbon nanotube/natural rubber (CNT/NR) composite. An aligned CNT/NR system is constructed by atomic potential function and periodic boundary condition and the anisotropic thermal conductivity is predicted in three main directions. The highest thermal conductivity of 80 W/(mK) is predicted along the axial direction of CNT. However, the transverse thermal conductivity perpendicular to the CNT axis is only about 0.6 W/(mK). For obtaining thermal conductivity of randomly oriented CNT/NR composite, an isotropic algorithm is provided from thermal resistance analysis method and results indicate the thermal conductivity improvement of randomly oriented CNT/NR composite is negligible. It is deduced therefore aligning CNTs in NR matrix can be a promising method in thermal management of CNT/NR composite.


2020 ◽  
Vol 8 (14) ◽  
pp. 4801-4809 ◽  
Author(s):  
Dong An ◽  
Shuaishuai Cheng ◽  
Can Jiang ◽  
Xiaoyuan Duan ◽  
Bo Yang ◽  
...  

Polymer-based thermal management materials have drawn much attention in the last few years because of the increasing heat dissipation challenges of advanced modern electronics.


2020 ◽  
pp. 0021955X2097954
Author(s):  
Pollawat Charoeythornkhajhornchai ◽  
Wutthinun Khamloet ◽  
Pattharawun Nungjumnong

Natural rubber composite foam with carbon such as carbon black (CB), carbon synthesized from durian bark (CDB), graphite (GPT), graphene oxide (GO), graphene (GPE) and multi-walled carbon nanotubes (MWCNT) was studied in this work to investigate the relationship between foam formation during decomposition of chemical blowing agent mechanism and crosslink reaction of rubber molecules by sulphur. Natural rubber composite foam with carbon particle was set at 3 parts per hundred of rubber (phr) to observe the effect of carbon allotropes on foam formation with different microstructure and properties of natural rubber composite foam. The balancing of crosslink reaction by sulphur molecules during foam formation by the decomposition of chemical blowing agent affects the different morphology of natural rubber foam/carbon composites leading to the different mechanical and thermal properties. The result showed the fastest cure characteristics of natural rubber foam with 3 phr of graphene (NRF-GPE3) which was completely cure within 6.55 minutes (tc90) measured by moving die rheometer resulting in the smallest bubble diameter among other formulas. Moreover, natural rubber foam with 3 phr of MWCNT (NRF-MWCNT3) had the highest modulus (0.0035 ± 0.0005 N/m2) due to the small bubble size with high bulk density. In addition, natural rubber foam with 3 phr of GPT (NRF-GPT3) had the highest thermal expansion coefficient (282.12 ± 69 ppm/K) due to high amount of gas bubbles inside natural rubber foam matrix and natural rubber foam with 3 phr of GO (NRF-GO3) displayed the lowest thermal conductivity (0.0798 ± 0.0003 W/m.K) which was lower value than natural rubber foam without carbon filler (NRF). This might be caused by the effect of bubble diameter and bulk density as well as the defect on surface of graphene oxide compared to others carbon filler.


2013 ◽  
Vol 753-755 ◽  
pp. 2379-2382
Author(s):  
Shi Meng Xu ◽  
Run Bo Ma ◽  
Jian Hua Du ◽  
Jun Hong Liu ◽  
Qi Jin

Filled the N330 carbon black, silica T80 carbon black and Al powder and Fe2O3 magnetic nanoparticles, the rubber composites on multi-component electromagnetic fillers were prepared according to orthogonal experiment analysis, and the preliminary experiment conclusions of the filler prescription designs were given; Based on the experiment design, the mechanical properties and thermal conductivity of the rubber composite were tested, and the testing results were analyzed by using variance analysis. Thus, the paper shows that the effects of N330 on rubber mechanical properties are significant, and the effects of Al powder on the rubber thermal conductivity are significant. Moreover, it is highly emphasized in this paper that the orthogonal experiment design must be carefully explored before the tests are executed.


2018 ◽  
Vol 934 ◽  
pp. 43-49
Author(s):  
Poramin Boonprasert ◽  
Nuchnapa Tangboriboon

Natural rubber composite materials were prepared by using sulfur curing system of STR 5L added with hen eggshell and eggshell membrane to increase electrical and mechanical properties for biomimetic actuator and artificial muscle applications. Samples were vulcanized at temperature 150°C. Hen eggshells and eggshell membrane powder (0, 20, 40, and 60 phr) were added into natural rubber. The main composition of hen eggshells composed of 96.35 wt% calcium carbonate (CaCO3) while mostly composition of hen eggshell membrane is fibrous protein in terms of collagen. The best condition is addition of eggshell 40 phr (formula 3) and eggshell membrane 20 phr (formula 5) to obtain the highest storage modulus response equal to 2.85 x 106 and 2.97 x106 Pa, respectively. The curing time (Tc90) of pure natural rubber (formula 1), formula 3, and formula 5 are 8.22, 6.73, and 5.67 min, respectively. Furthermore, the curing time, rheology, and electrical field response of natural rubber composite materials were measured by moving die rheometer and impedance analyzer, and reported here.


1999 ◽  
Vol 35 (9) ◽  
pp. 1687-1693 ◽  
Author(s):  
N.S. Saxena ◽  
P. Pradeep ◽  
G. Mathew ◽  
S. Thomas ◽  
M. Gustafsson ◽  
...  

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