Structure, Crystallization and Thermal Behavior of Fluorinated ethylene propylene (FEP) based Plastics Composites

The FEP based binary and ternary plastics composites were prepared by melt blending. The microstructure, crystallization behavior and thermal degradation behavior of FEP/PEEK, FEP/PEI and FEP/PEEK/PEI composites were investigated by FT-IR, SEM, DSC, XRD and TGA. The FT-IR, SEM and DSC results shows...

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Date:2018
Main Authors: Chen Jian-bing, Li Zhun-zhun, Xu Nan
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Language:English
Published: НТК «Інститут монокристалів» НАН України 2018
Series:Functional Materials
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Cite this:Structure, Crystallization and Thermal Behavior of Fluorinated ethylene propylene (FEP) based Plastics Composites / Chen Jian-bing, Li Zhun-zhun, Xu Nan // Functional Materials. — 2018. — Т. 25, № 1. — С. 93-99. — Бібліогр.: 12 назв. — англ.

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spelling nasplib_isofts_kiev_ua-123456789-1544632025-02-09T16:39:50Z Structure, Crystallization and Thermal Behavior of Fluorinated ethylene propylene (FEP) based Plastics Composites Chen Jian-bing Li Zhun-zhun Xu Nan Characterization and properties The FEP based binary and ternary plastics composites were prepared by melt blending. The microstructure, crystallization behavior and thermal degradation behavior of FEP/PEEK, FEP/PEI and FEP/PEEK/PEI composites were investigated by FT-IR, SEM, DSC, XRD and TGA. The FT-IR, SEM and DSC results shows that the FEP/PEEK, FEP/PEI and FEP/PEEK/PEI composites were presented thermodynamics incompatible. The degree of crystallinity of FEP was decreased as PEEK or with PEI simultaneously were added to FEP matrix, while the degree of crystallinity of FEP increases first then decreases as PEI was added to FEP matrix. The TGA results shows that the thermal stability of FEP/PEEK composites enhance with PEEK content increases when the PEEK content is under 25%, then decreased when the PEEK content is over 25%, the thermal stability of FEP/PEI and FEP/PEEK/PEI composites decreased with PEI or PEEK added to the FEP matrix. This work was financially supported by the Key Projects of the Outstanding Young Talents in Colleges and Universities of Anhui Province (gxyqZD2016373) and the Innovation Practice rojects of Chemistry and Materails(2014sjjd029). 2018 Article Structure, Crystallization and Thermal Behavior of Fluorinated ethylene propylene (FEP) based Plastics Composites / Chen Jian-bing, Li Zhun-zhun, Xu Nan // Functional Materials. — 2018. — Т. 25, № 1. — С. 93-99. — Бібліогр.: 12 назв. — англ. 1027-5495 DOI:https://doi.org/10.15407/fm25.01.093 https://nasplib.isofts.kiev.ua/handle/123456789/154463 en Functional Materials application/pdf НТК «Інститут монокристалів» НАН України
institution Digital Library of Periodicals of National Academy of Sciences of Ukraine
collection DSpace DC
language English
topic Characterization and properties
Characterization and properties
spellingShingle Characterization and properties
Characterization and properties
Chen Jian-bing
Li Zhun-zhun
Xu Nan
Structure, Crystallization and Thermal Behavior of Fluorinated ethylene propylene (FEP) based Plastics Composites
Functional Materials
description The FEP based binary and ternary plastics composites were prepared by melt blending. The microstructure, crystallization behavior and thermal degradation behavior of FEP/PEEK, FEP/PEI and FEP/PEEK/PEI composites were investigated by FT-IR, SEM, DSC, XRD and TGA. The FT-IR, SEM and DSC results shows that the FEP/PEEK, FEP/PEI and FEP/PEEK/PEI composites were presented thermodynamics incompatible. The degree of crystallinity of FEP was decreased as PEEK or with PEI simultaneously were added to FEP matrix, while the degree of crystallinity of FEP increases first then decreases as PEI was added to FEP matrix. The TGA results shows that the thermal stability of FEP/PEEK composites enhance with PEEK content increases when the PEEK content is under 25%, then decreased when the PEEK content is over 25%, the thermal stability of FEP/PEI and FEP/PEEK/PEI composites decreased with PEI or PEEK added to the FEP matrix.
format Article
author Chen Jian-bing
Li Zhun-zhun
Xu Nan
author_facet Chen Jian-bing
Li Zhun-zhun
Xu Nan
author_sort Chen Jian-bing
title Structure, Crystallization and Thermal Behavior of Fluorinated ethylene propylene (FEP) based Plastics Composites
title_short Structure, Crystallization and Thermal Behavior of Fluorinated ethylene propylene (FEP) based Plastics Composites
title_full Structure, Crystallization and Thermal Behavior of Fluorinated ethylene propylene (FEP) based Plastics Composites
title_fullStr Structure, Crystallization and Thermal Behavior of Fluorinated ethylene propylene (FEP) based Plastics Composites
title_full_unstemmed Structure, Crystallization and Thermal Behavior of Fluorinated ethylene propylene (FEP) based Plastics Composites
title_sort structure, crystallization and thermal behavior of fluorinated ethylene propylene (fep) based plastics composites
publisher НТК «Інститут монокристалів» НАН України
publishDate 2018
topic_facet Characterization and properties
url https://nasplib.isofts.kiev.ua/handle/123456789/154463
citation_txt Structure, Crystallization and Thermal Behavior of Fluorinated ethylene propylene (FEP) based Plastics Composites / Chen Jian-bing, Li Zhun-zhun, Xu Nan // Functional Materials. — 2018. — Т. 25, № 1. — С. 93-99. — Бібліогр.: 12 назв. — англ.
series Functional Materials
work_keys_str_mv AT chenjianbing structurecrystallizationandthermalbehavioroffluorinatedethylenepropylenefepbasedplasticscomposites
AT lizhunzhun structurecrystallizationandthermalbehavioroffluorinatedethylenepropylenefepbasedplasticscomposites
AT xunan structurecrystallizationandthermalbehavioroffluorinatedethylenepropylenefepbasedplasticscomposites
first_indexed 2025-11-28T01:24:12Z
last_indexed 2025-11-28T01:24:12Z
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fulltext Functional materials, 25, 1, 2018 93 ISSN 1027-5495. Functional Materials, 25, No.1 (2018), p. 93-99 doi:https://doi.org/10.15407/fm25.01.93 © 2018 — STC “Institute for Single Crystals” Structure, crystallization and thermal behavior of fluorinated ethylene �ro�ylene ������ basedfluorinated ethylene �ro�ylene ������ based������ based �lastics com�osites ����� ������������� �� ������������� �� ��������� ������������� �� ������������� �� ���� School of Chemistry and Materials Engineering, Chizhou University, Chizhou, Anhui, 247000, P.R. China Received December 5, 2017 The FEP based binary and ternary plastics composites were prepared by melt blending. The microstructure, crystallization behavior and thermal degradation behavior of FEP/PEEK, FEP/ PEI and FEP/PEEK/PEI composites were investigated by FT-IR, SEM, DSC, XRD and TGA. The FT-IR, SEM and DSC results shows that the FEP/PEEK, FEP/PEI and FEP/PEEK/PEI composites were presented thermodynamics incompatible. The degree of crystallinity of FEP was decreased as PEEK or with PEI simultaneously were added to FEP matrix, while the degree of crystallinity of FEP increases first then decreases as PEI was added to FEP matrix. The TGA results shows that the thermal stability of FEP/PEEK composites enhance with PEEK content increases when the PEEK content is under 25%, then decreased when the PEEK content is over 25%, the thermal stability of FEP/PEI and FEP/PEEK/PEI composites decreased with PEI or PEEK added to the FEP matrix. Keywords: FEP, PEEK, PEI, microstructure, crystallization behavior, thermal degradation Бинарные и тройные пластиковые композиты на основе фторированного этиленпропилена (FEP) были приготовлены путем смешивания в расплаве. Микроструктура, поведение кристаллизации и поведение тепловой деградации композитов FEP / PEEK, FEP / PEI и FEP / PEEK / PEI были исследованы с помощью FT-IR, SEM, DSC, XRD и TGA методов. Результаты показывают, что композиты FEP / PEEK, FEP / PEI и FEP / PEEK / PEI являются термодинамически несовместимыми. Степень кристалличности FEP уменьшалась, поскольку PEEK или PEI одновременно добавлялись к матрице FEP, тогда как степень кристалличности FEP сначала возрастала, а затем уменьшалась по мере добавления PEI к матрице FEP. Показано, что термическая стабильность композитов FEP / PEEK увеличивается с увеличением содержания PEEK, когда содержание PEEK составляет менее 25%, а затем уменьшается, когда содержание PEEK превышает 25%. Термическая стабильность FEP / PEI и FEP / PEEK/ композиты PEI уменьшается с добавлением PEI или PEEK к матрице FEP. Структура, кристалізація та термічні властивості пластмасових композитів на основі фторованих етіленпропілена (FEP). Chen Jian-bing, Li Zhun-zhun, Xu Nan. Бінарні і потрійні пластикові композити на основі фторованих етіленпропілена (FEP) були приготовлені шляхом змішування в розплаві. Мікроструктуру, поведінку кристалізації і поведінку теплової деградації композитів FEP / PEEK, FEP / PEI і FEP / PEEK / PEI досліджено за допомогою FT-IR, SEM, DSC, XRD і TGA методів. Результати показують, що композити FEP / PEEK, FEP / PEI і FEP / PEEK / PEI є термодинамічно несумісними. Ступінь кристалічності FEP зменшувалася, оскільки PEEK або PEI одночасно додавалися до матриці FEP, тоді як ступінь кристалічності FEP спочатку зростала, а потім зменшувалася у міру додавання PEI до матриці FEP. Показано, що термічна стабільність композитів FEP / PEEK збільшується зі збільшенням вмісту PEEK, коли вміст PEEK становить менше 25%, а потім зменшується, коли вміст PEEK перевищує 25% . Термічна стабільність FEP / PEI і FEP / PEEK / композити PEI зменшується. Термічна стабільність FEP / PEI і FEP / PEEK / композити PEI зменшується з додаванням PEI або PEEK до матриці FEP. 94 Functional materials, 25, 1, 2018 Chen Jian-bing et al. / Structure, crystallization and thermal behavior ... 1. Introduction (FEP) can be consider as modified polytet- rafluoroethylene (PTFE), which is a copolymer of tetrafluoroethylene and hexafuoropropylene via free-radical polymerization. FEP is a kind of crystalline polymer, with similar in compo- sition to the PTFE. FEP share the excellent properties of PTFE such as low friction, non- reactivity, corrosion resistance, low dielectric constant, uninflammable and excellent me- chanical properties. Compared with PTFE, FEP have better processing property, because FEP having a melting point of 250~270 °C, around 40 °C lower than Perluoroalkoxy polymer resin (PFA), and lower than PTFE.[1-2] FEP have widely used for wiring due to the properties of low dielectric constant and uninflammable.[3] In addition, because of the chemical composure and chemical fuels resistance in extreme tem- peratures, flexibility and optical transparency, FEP can be used as “release films” in manu- facturing high-quality composites parts, and used for the application of plastic labware and medical apparatus and instruments.[4] Howev- er, the processing properties of FEP are better than some engineering plastics, but the tensile strength, creep resistance and abrasive resis- tance are reverse, which restricts its further application. In order to extending the application fields of FEP, many researchers has been studied the modification of FEP with other polymers such as polypropylene (PP), Polyimide (PI), PTFE and polystyrene (PS). However, because of the chemical inertness of FEP, the repeated FEP based composites were prepared by radia- tion grafting method[5-7] and spray method. Liang J Z et al[8] prepared the FEP/PP com- posites by melt extrusion molding, the melt shear behavior of PP, FEP and FEP/PP were investigated by Bohlin higher rheometer. The results showed that the melt shear viscosity of PP and FEP/PP composites conforms with the Arrhenius equation, FEP and FEP/PP com- posites presented obvious shear thinning with shear rate increases, the zero-shear viscosity of FEP/PP composites was enhanced with the weight fraction of PP increases. Zhao H et al[9] investigated the tribological properties od PI/ FEP self-lubricating composites with dry slid- ing, water-lubricated and oil-lubricated con- ditions. The results showed that the friction coefficients of PI/FEP composites under water lubrication were lower than under dry sliding, the wear rates were higher than under dry sliding. There exists lowest friction coefficients and wear rates under oil-lubricated condition. Wang H et al[10] repeated that the polyphen- ylene sulfide (PPS)/FEP/polyetheretherketone (PEEK)/polydimethylsiloxane (PMDS) com- posite coating with excellent self-cleaning, bending/heat/wear-resistance and heating-sta- bility properties have been prepared by spray method. The research results showed that the contact angles of water, glycerine, ethylene gly- col, crude oil and oil-water mixture were over 151°, and even up to 173°. The wear life was 10 times as compared with PPS/PEEK coating, the brittleness and chemical reagent resistant of PPS/FEP/PEEK/PDMS coating was signifi- cantly better than PPS/PEEK coating. Blend alloy is one of the most effective means to improving the properties of polymer due to large improvement has been achieved in the characteristics including thermal prop- erties, mechanical properties, crystallizability and cost effectiveness by blending appropriate polymer materials [11–12]. In this article, the binary and ternary plastic composites of FEP, PEEK and poly(etherimide) (PEI) were fabri- cated by melt blending, the effects of crystal polymer PEEK and amorphous polymer PEI on the crystalline and thermal properties of crys- tal polymer FEP were investigated by FT-IR, SEM, DSC, XRD and TGA. 2. Experimental materials and sample preparation The FEP, PEEK and PEI used in this work were obtained by Dupont, the glass-transition temperature (Tg), melting point and thermal decomposition temperature (Td) of FEP, PEEK and PEI were listed in Table 1. The materials were preliminarily dried at 120 °C for 5 hours, and then melt blended using a twin-screw ex- truder (model: SHJ-20, Nanjing Yajie Extrusion Equipment Co. Ltd., China). Extrusion process- ing parameters: temperatures of extruder sec- tions for 230~365 °C, screw speed 10~30 r/min, head pressure 9~11 MPa. 2.1. ��aracteri�ations��aracteri�ations The chemical structures of the FEP/PEEK/ PEI composites were analyzed by Fourier Transform Infrared Spectroscopy (FTIR) (Nico- let IS–10). The spectra were recorded from 400 to 4000 cm–1 with a resolution of 2 cm–1 and 32 scans. The microstructural of FEP/PEEK/ Table 1. The thermodynamic parameters of FEP, PEEK and PEI Materials Tg , °C Melting point, °C Td, °C FEP 30 265~285 460 PEEK 150 343 520 PEI 215~217 334 515 Functional materials, 25, 1 2018 95 Chen Jian-bing et al. / Structure, crystallization and thermal behavior ... PEI composites were observed by Scanning electron microscope (SEM) (HITACHI S-4800). The crystallization and thermal decomposition behaviors of FEP/PEEK/PEI composites were studied by X-ray diffraction (XRD) (DX-2700), differential scanning calorimetry (DSC) (TA Q- 2000) and thermal gravimetric analyzer (TGA) (TA Q-2000) with a nitrogen atmosphere, respectively. The testing temperature were 20~450 °C and 20~800 °C heated at 10 °C/min. 4.Results and Discussion 4.1.��emical Structure and Micro- structure of FEP based composites Figure 1 shows the FT-IR spectrum of pure FEP, PEEK and PEI plastics.The absorption peak observed at 1154 cm–1 was due to stretch- ing vibrations of C-F groups present in the spectrum of FEP. The peak appeared at 1654 cm–1, 1597 cm–1, 1220 cm–1 and 1014 cm–1 were belong to the stretching vibrations of C=O, benzene, Ø-O-Ø and C-O groups present in the spectrum of PEEK. The peak appeared at 1776 cm–1, 1597 cm–1, 1355 cm–1 and 1014 cm–1 were belong to the stretching vibrations of C=O, ben- zene, C-N and C-O groups present in PEI. The FT-IT spectrum and characteristic ab- sorption peak of the binary plastic composites of FEP/PEEK, FEP/PEI and FEP/PEEK/PEI ternary plastic composites were show in Figure 2 and Table 3. The characteristic peak of FEP/ PEEK composites appeared as linear superpo- sition. With the content of PEEK increases, the characteristic peak position remain unchanged, while the peak area decreases slightly, as shown in Figure 2(a) and Table 3. As shown in Figure 2(b) and Table 3, it was observed that the characteristic peak of FEP and PEI were appears at the spectrum of FEP/ PEI composites, entirely. However, the peak position of C-N present at PEI was shifted from Table 2. Detailed formulae of FEP/PEEK/PEI composites Materials FEP (phr) PEEK (phr) PEI (phr) P100-K0-I0 100 0 0 P0-K100-I0 0 100 0 P0-K0-I100 0 0 100 P85-K15-I0 85 15 0 P80-K20-I0 80 20 0 P75-K25-I0 75 25 0 P70-K30-I0 70 30 0 P95-K0-I5 95 0 5 P92-K0-I8 92 0 8 P90-K0-I10 90 0 10 P85-K0-I15 85 0 15 P80-K0-I20 80 0 20 P90-K5-I5 90 5 5 P85-K10-I5 85 10 5 P80-K15-I5 80 15 5 P75-K20-I5 75 20 5 Fig. 1. FT-IR spectrum of pure FEP, PEEK and PEI (a: FEP; b: PEEK; c: PEI) Fig. 2. FT-IR spectrum of FEP/PEEK, FEP/PEI and FEP/PEEK/PEI composites 96 Functional materials, 25, 1, 2018 Chen Jian-bing et al. / Structure, crystallization and thermal behavior ... 1355 cm–1 to 1360 cm–1 when PEI was added to FEP, the peak symmetry of FEP/PEI com- posites was changed from FEP to PEI as in- creasing the content of PEI. It indicated that there exists weak interaction between FEP and PEEK. As compared with pure FEP, PEEK and PEI, the FT-IR spectrum of FEP/PEEK/PEI ternary composites was changed apparently, as shown in Figure 2(c) and Table 3. The stretch- ing vibrations peak of C-F was shifted from 1154 cm–1 to 1146 cm–1, and the peak symme- try was changed. The absorption peak of C-N was shifted from 1355 cm–1 to 1403 cm–1, while the peak position of C=O was shifted from 1654 cm–1 to 1622 cm–1. From Figure 2(a) and Figure 2(b ), there almost have no interaction between the groups of FEP with PEEK and PEI, which can proved that the FT-IR spectrum changes of FEP/PEEK/PEI ternary composites was caused by the interaction of the polar groups presents at PEEK and PEI. The SEM images of FEP based binary and ternary composites were shown in Figure 3. As shown in Figure 3(a), for FEP/PEEK binary composites, the filiform substance was con- sidered as PEEK, which was dispersed in the matrix of FEP phase and there was a distinct interface between FEP and PEEK phase. For FEP/PEI composites, the PEI phase present- ed as particles was evenly distributed among the matrix of FEP phase and there was a dis- tinct interface between FEP and PEI phase, as shown in Figure 3(b). In Figure 3(c), it can be observed that there was exists two-phase struc- ture, many particles which was considered as PEEK and PEI mixed phase speculated by the formula content of FEP/PEEK/PEI ternary composites and FEP/PEEK/PEI FT-IR spec- trum, the particles was uniformly dispersed in the matrix. In addition, there exists a dis- Table 3. Characteristic absorption peak of the FEP based binary and ternary plastics composites Materials C=O C-O C-F Ø-O-Ø C=O at imine ring C-N P100-K0-I0 — — 1154 — — — P0-K100-I0 1654 1014 — 1220 — — P0-K0-I100 — 1015 — — 1776 1355 P70-K30-I0 1654 1014 1154 1220 — — P75-K25-I0 1654 1014 1154 1220 — — P95-K0-I5 — 1015 1154 — 1776 1360 P90-K0-I10 — 1015 1154 — 1776 1360 P85-K0-I15 — 1015 1154 — 1776 1360 P80-K0-I20 — 1015 1154 — 1776 1360 P90-K5-I5 1622 1015 1146 1220 — 1403 P85-K10-I5 1622 1015 1146 1220 — 1403 P80-K15-I5 1622 1015 1146 1220 — 1403 P75-K20-I35 1622 1015 1146 1220 — 1403 Fig. 3. SEM images of FEP/PEEK, FEP/PEI and FEP/PEEK/PEI composites (a: P70-K30-I0; b: P85-K0- I15; c: P85-K10-I5) Functional materials, 25, 1 2018 97 Chen Jian-bing et al. / Structure, crystallization and thermal behavior ... tinct interface between particles and matrix in FEP/PEEK/PEI composites. From the SEM im- ages of FEP based composites, it can indicated that FEP/PEEK, FEP/PEI and FEP/PEEK/PEI were not miscible in thermodynamics, because of the chemical inertness structure of FEP, and the PEEK and PEI were miscible in thermody- namics, which was consistent with the FT-IR spectrum. 4.2.�rystalli�ation and t�ermodynam- ics be�avior of FEP based composites The DSC curves and DSC measurement data of FEP/PEEK, FEP/PEI and FEP/PEEK/ PEI composites were shown in Figure 4 and Table 4. The degree of crystallinity (Xc) of FEP/PEEK, FEP/PEI and FEP/PEEK/PEI composites were determined from the area of endothermic melting peaks were shown in Figure 5. As shown in Figure 4(a) and Table 4, the DSC curve of FEP/PEEK shows that the crystal-melting peak of FEP/PEEK composites and melting peak of FEP were increased with the content of PEEK increases. According to the DSC curves and SEM images, it can deducededuce that the Tm3 corresponds to PEEK and Tm2 corresponds to PEEK and FEP composites. The Xc curve of FEP/PEEK was shown in Figure 5(a), it can be seen that the Xc of FEP/PEEK composites decreased with the content of PEEK increases, the Xc of FEP/PEEK composites decreased was caused by the crystalline region were destroyed as PEEK added. From the DSC curve and measurement data of FEP/PEI composites can be seen with the con- tent of PEI increases, the crystal-melting peak of FEP first increased and then decreased, and the Xc of FEP/PEI composites were increases first and then decreases. When the content of PEI was under 15%, the heterogeneous nucle- ating effect of PEI increases the nucleating and crystallizing rate, and then achieved improve- Table 4. DSC measurement data of FEP/ PEEK, FEP/PEI and FEP/PEEK/PEI com- posites Materials Tm1 Tm2 Tm3 Tc P70-K30-I0 262.90 345.50 ─ 185.90 P75-K25-I0 262.89 339.20 346.30 175.90 P80-K20-I0 262.64 337.80 347.80 174.60 P85-K15-I0 262.60 337.14 345.74 176.64 P95-K0-I5 259.30 ─ ─ ─ P92-K0-I8 260.10 ─ ─ ─ P90-K0-I10 260.44 ─ ─ ─ P85-K0-I15 262.60 ─ ─ ─ P80-K0-I20 261.40 ─ ─ ─ P90-K5-I5 262.80 338.40 ─ 209.30 P85-K10-I5 263.60 332.19 342.79 206.49 P80-K15-I5 262.40 332.80 345.50 205.90 P75-K20-I5 261.44 335.84 346.24 196.84 Fig. 4. DSC curves of FEP/PEEK, FEP/PEI and FEP/PEEK/PEI composites Fig. 5. Xc changing curves of FEP/PEEK, FEP/PEI and FEP/PEEK/PEI composites 98 Functional materials, 25, 1, 2018 Chen Jian-bing et al. / Structure, crystallization and thermal behavior ... ment of the melt point and Xc of FEP. When the content of PEI was over 15%, the crystal- line region of FEP was destroyed, the Xc of FEP decreased, the melting peak decreases. Figure 4(c) and Figure 5(c) shows the DSC and Xc curves of FEP/PEEK/PEI curves, the melt point of Tm1, Tm2 and Tm3 were corresponds to FEP, PEI and PEEK, respectively. It can be seen that the melt point of FEP were decreased, while the melt point of PEI and PEEK increased as the content of PEEK increases. The Xc of FEP was decreasedwas decreased decreased with increases the content of PEEK, which was caused by the crystalline region were destroyed as PEEK content increases. Figure 6 and Table 5 shows the XRD data of FEP/PEEK, FEP/PEI and FEP/PEEK/PEI composites. It can seen that the crystalline dif- fraction peaks of PEEK can not be discovered in Figure 6(a), with the content of PEEK in- creases, the half peak width of FEP were in- creases, which revealed that the grain size of FEP decreases with PEEK increases. For FEP/ PEI composites, when the content of PEI was under 15 %, the half peak width of FEP diffrac- tion peak decreases with PEI content increases. For FEP/PEEK/PEI composites, the PEI con- centration remain unchanged, with the PEEK content increases, the half peak width of FEP diffraction peak increases, which revealed that with PEEK increases, the grain size of FEP de- creases. Figure 7 and Table 6 shows the thermal sta- bility of FEP based composites. It can be seen that the Ti, Tm and Tf of FEP/PEEK composites enhance with PEEK content increases when the PEEK content is under 25%, and decreased when the PEEK content is over 25%. For FEP/ PEI composites, the Ti and Tm decreased with PEI content increases, while the Tf increas- es. For FEP/PEEK/PEI composites, the PEI content remain constant, when the content of PEEK increases, the Ti, Tm and Tf of FEP/ PEEK/PEI composites decreases. Fig. 6. XRD diffraction pattern of FEP/PEEK, FEP/PEI and FEP/PEEK/PEI composites Table 5. XRD measurement data of FEP/ PEEK, FEP/PEI and FEP/PEEK/PEI com- posites Materials 2θ/° Half peak width P70-K30-I0 17.899 0.56 P75-K25-I0 17.680 0.46 P80-K20-I0 17.880 0.44 P85-K15-I0 17.162 0.41 P95-K0-I5 17.980 0.44 P92-K0-I8 17.702 0.41 P90-K0-I10 18.039 0.43 P85-K0-I15 17.519 0.41 P90-K5-I5 17.961 0.41 P85-K10-I5 17.619 0.43 P80-K15-I5 18.020 0.51 P75-K20-I5 17.158 0.66 Fig. 7. TGA curves of FEP/PEEK, FEP/PEI and FEP/PEEK/PEI composites Functional materials, 25, 1 2018 99 Chen Jian-bing et al. / Structure, crystallization and thermal behavior ... 5.�onclusion In this article, the FEP based binary and ternary plastic composites were fabricated by melting blend method. The structure, crystal- line and thermal properties were investigated by FT-IR, SEM, DSC, XRD and TGA. The FEP/ PEEK, FEP/PEI and FEP/PEEK/PEI compos- ites were presented thermodynamics incom- patible according to the FT-IR, SEM and DSC analysis. The DSC measurement data shows that the Xc of FEP/PEEK decreases as PEEK content increases, the Xc of FEP/PEI enhance with PEI content increases when the PEI con- tent under 15 %, and decreases when the PEI content over 15 %. For FEP/PEEK/PEI, the PEI content remain constant, with PEEK in- creases, the Xc of FEP/PEEK/PEI decreases. The XRD results shows that the grain size of FEP/PEEK decreases with PEEK increases, for FEP/PEI composites, when the content of PEI was under 15 %, the half peak width of FEP diffraction peak decreases with PEI content in- Table 6. TGA measurement data of FEP/ PEEK, FEP/PEI and FEP/PEEK/PEI com- posites Materials Initial degrada- tion tem- perature (Ti) maximum mass loss rate tem- perature (Tm) Finish degrada- tion tem- perature (Tf) P70-K30-I0 474.76 519.52 535.77 P75-K25-I0 484.12 530.98 551.51 P80-K20-I0 483.61 529.89 549.95 P85-K15-I0 471.87 529.71 549.84 P92-K0-I8 496.72 532.66 542.79 P90-K0-I10 438.35 532.72 546.94 P85-K0-I15 432.53 526.87 551.38 P80-K0-I20 450.05 520.95 551.88 P90-K5-I5 470.67 522.77 550.95 P85-K10-I5 467.18 524.27 549.15 P80-K15-I5 450.78 514.28 544.61 P75-K20-I5 438.45 526.09 547.50 creases. For FEP/PEEK/PEI composites, with the PEEK content increases, the half peak width of FEP diffraction peak increases, which revealed that with PEEK increases, the grain size of FEP decreases. The TGA results shows that the Ti, Tm and Tf of FEP/PEEK composites enhance with PEEK content increases when the PEEK content is under 25%, and decreased when the PEEK content is over 25%, the Ti and Tm of FEP/PEI decreased with PEI content in- creases, while the Tf increases. For FEP/PEEK/ PEI composites, the PEI content remain con- stant, when the content of PEEK increases, the Ti, Tm and Tf of FEP/PEEK/PEI composites de- creases. Acknowledgements This work was financially supported by the Key Projects of the Outstanding Young Talents in Colleges and Universities of An- hui Province (gxyqZD2016373) and the In- novation Practice rojects of Chemistry and Materails(2014sjjd029).. References 1. Sahlin E, Beisler A T, Woltman S J, et al.. Anal. Chem., 74, 4566, 2011. 2. Bernett M K, Zisman W A., J.Phys.l Chem., 64, 1292,1960. 3. Fujii H, Okumura T, Takahashi M, Electr. Eng. Japan, 188, 9, 2014. 4. Jiang Z, Guo Z, Jia Z, et al., e-Polymers, 2016, 16(2): 171–176. 5. 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