Phase change materials based on low-density polyethylene/paraffin wax blends

被引:162
作者
Krupa, I. [1 ,2 ]
Mikova, G. [2 ]
Luyt, A. S. [1 ]
机构
[1] Univ Free State, Dept Chem, ZA-9866 Phuthaditjhaba, South Africa
[2] Slovak Acad Sci, Inst Polymer, Bratislava 84236, Slovakia
基金
新加坡国家研究基金会;
关键词
phase change materials; polyethylene; paraffin wax; DSC; DMA; miscibility;
D O I
10.1016/j.eurpolymj.2007.08.022
中图分类号
O63 [高分子化学(高聚物)];
学科分类号
070305 ; 080501 ; 081704 ;
摘要
Phase change materials, based on low-density polyethylene blended with soft and hard paraffin waxes respectively, were studied in this paper. DSC, DMA, TGA and SEM were employed to determine the structure and properties of the blends. The blends were able to absorb large amounts of heat energy due to melting of paraffin wax, whereas the LDPE matrix kept the material in a compact shape on macroscopic level. The hard paraffin wax was, however, much more miscible with LDPE because of co-crystallization than the soft paraffin wax. LDPE blended with hard paraffin wax degrades in just one step, while blends containing soft paraffin wax degrade in two distinguishable steps. SEM showed completely different morphology for the two paraffin waxes and confirmed the lower miscibility of LDPE and soft paraffin wax. DMA analyses demonstrated the toughening effect of the waxes on the polymer matrix. This technique was also used to follow the thermal expansion as well as the dimensional stability of the samples during thermal cycling. The most visible expansion could be seen in the first cycle, probably due to a totally different thermal history of the sample. With further cycling the dimensions stabilized after two and four cycles for soft and hard paraffin wax, respectively. Controlled force ramp testing on DMA confirmed poor material strength of the blends containing soft wax, especially at temperatures above wax melting. (c) 2007 Elsevier Ltd. All rights reserved.
引用
收藏
页码:4695 / 4705
页数:11
相关论文
共 17 条
[11]  
LUYT AS, UNPUB THERMOCHIM ACT
[12]   The effect of cross-linking on the thermal properties of LDPE/wax blends [J].
Mtshali, TN ;
Krupa, I ;
Luyt, AS .
THERMOCHIMICA ACTA, 2001, 380 (01) :47-54
[13]   Polymeric phase change composites for thermal energy storage [J].
Peng, S ;
Fuchs, A ;
Wirtz, RA .
JOURNAL OF APPLIED POLYMER SCIENCE, 2004, 93 (03) :1240-1251
[14]   Form-stable paraffin/high density polyethylene composites as solid-liquid phase change material for thermal energy storage: preparation and thermal properties [J].
Sari, A .
ENERGY CONVERSION AND MANAGEMENT, 2004, 45 (13-14) :2033-2042
[15]   Preparation and performance of shape stabilized phase change thermal storage materials with high thermal conductivity [J].
Xiao, M ;
Feng, B ;
Gong, KC .
ENERGY CONVERSION AND MANAGEMENT, 2002, 43 (01) :103-108
[16]   Thermal performance of a high conductive shape-stabilized thermal storage material [J].
Xiao, M ;
Feng, B ;
Gong, KC .
SOLAR ENERGY MATERIALS AND SOLAR CELLS, 2001, 69 (03) :293-296
[17]   Review on thermal energy storage with phase change:: materials, heat transfer analysis and applications [J].
Zalba, B ;
Marín, JM ;
Cabeza, LF ;
Mehling, H .
APPLIED THERMAL ENGINEERING, 2003, 23 (03) :251-283