Preparation and properties of an ultraviolet cut⁃off POE photovoltaic encapsulation film

doi:10.19491/j.issn.1001-9278.2025.04.001

Abstract

Abstract:

In this study， hydrogenated hydrocarbon resin （H⁃HCR） was melt blended with POE using dicumyl peroxide （DCP） as a crosslinking agent and hexadecyl 3，5⁃di⁃tert⁃butyl⁃4⁃hydroxy⁃benzoate （UV2908） as a UV absorbers for fabricating a UV cut⁃off PV encapsulation film with high volume resistance. The transmittance of the blending films in the UV region （250~380 nm） was significantly reduced with an increase in the H⁃HCR content， and its high transmittance in the visible/near⁃infrared region of 380~1 100 nm was maintained. Meanwhile， UV2908 exhibited excellent UV cut⁃off performance in the range of 250~292 nm. The two components could generate a synergistic effect to prevent UV from entering PV modules， resulting in the formation of a PV encapsulation film with a high UV cut⁃off function. Meanwhile， the mechanical properties and volume resistivity of the blending films were significantly enhanced， and their volume resistivity reached the highest value at an H⁃HCR content of 15 wt%. When the POE/H⁃HCR/DCP/UV2908 mass ratio was 85/15/1.5/0.2， the average transmittance and UV cut⁃off wavelength of the blending films in the visible/near⁃infrared region are 91.6 % and 284 nm， respectively. Their tensile strength， elongation at break and volume resistivity reached 20.1 MPa， 904 % and 5.9×10¹⁵ Ω·cm， respectively. The blending materials demonstrated not only good volume resistivity and mechanical properties but also excellent UV cut⁃off performance.

Key words: photovoltaic encapsulant, high transmittance, ultraviolet cut-off, volume resistivity, composite material

CLC Number:

TQ334.2

HE Hezhi, XIONG Huawei, LAI Wen. Preparation and properties of an ultraviolet cut⁃off POE photovoltaic encapsulation film[J]. China Plastics, 2025, 39(4): 1-7.

Figures/Tables 9

样品	POE含量/%	DCP含量/%	H⁃HCR含量/%	UV2908含量/%
POE	100	1	-	-
POE⁃5	100	1	5	-
POE⁃10	100	1	10	-
POE⁃15	100	1	15	-
POE⁃2uv	100	1	-	0.2
POE⁃4uv	100	1	-	0.4
POE⁃6uv	100	1	-	0.6
POE⁃5/uv	100	1	5	0.2
POE⁃10/uv	100	1	10	0.2
POE⁃15/uv	100	1	15	0.2

Tab.1. Components of all samples

Fig.1. Temperature⁃rise rheological curves and isothermal rheological curves at different curing temperatures of the investigated peroxide⁃crosslinking POE blends

Fig.2. UV/VIS/NIR transmission spectra of POE blends encapsulant

样品	m₀/g	m₁/g	m₂/g	交联度/%
POE	0.478	3.545	3.498	90.02
POE⁃5	0.478 13	4.145 55	4.072 19	84.66
POE⁃10	0.549 33	3.370 87	3.261 59	80.11
POE⁃15	0.491 54	4.014 73	3.891 75	74.98

Tab.2. Crosslinking degree for the crosslinked POE/DCP and POE/H⁃HCR/DCP blends

Fig.3. Volume resistance of POE/H⁃HCR/DCP/UV2908 blends with different H⁃HCR content

Fig.4. Stress⁃strain curve and tensile strength and elongation at break of POE/DCP/UV2908 and POE/H⁃HCR/DCP/UV2908 blends after crosslinking

Fig.5. The first heating DSC curves and DMA curves of POE/H⁃HCR/DCP blends with different H⁃HCR content

样品	T_g/℃	T_m/℃
POE	-37.4	44.2	65.4
H⁃HCR	—	91.4	—
POE⁃5	-33.1	44.5	65.9
POE⁃10	-28.1	44.8	66.2
POE⁃15	-25.8	45.2	66.7

Tab.3. Thermal properties of POE/DCP， H⁃HCR and their blends after crosslinking

Fig.6. FTIR spectra of neat POE and POE/H⁃HCR/DCP Blends

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