CC BY
3
St. Petersburg State Polytechnical University Journal. Physics and Mathematics. 2024. Vol. 17. No. 1 Научно-технические ведомости СПбГПУ. Физико-математические науки. 17 (1) 2024
Original article UDC 538.9
DOI: https://doi.org/10.18721/JPM.17103
THE EFFECT OF THE MONTMORILLONITE-BASED FILLER ON THE ELECTRET PROPERTIES OF POLYPROPYLENE E. A. Karulina 1 H, E. A. Volgina ’, S. M. Kulemina \
M. F. Galikhanov 23, A. M. Minzagirova 3
1 Herzen State Pedagogical University of Russia, St. Petersburg, Russia;
2 Institute of Applied Research, Tatarstan Academy of Sciences,
Kazan, Republic of Tatarstan, Russia;
3 Kazan National Research Technological University, Kazan,
Republic of Tatarstan, Russia и [email protected]
Abstract. In the paper, the studies of electret properties of polypropylene with different percentages of montmorillonite have been carried out by methods of thermally stimulated potential relaxation and thermally stimulated currents. A significant effect of filler concentration on the electret state stability was revealed. The parameters of electrically active defects and the storage time of the electret state were determined. It was established that polypropylene with a 4% mass content of montmorillonite exhibited the best electret properties.
Keywords: electret, composite polymer film, electret state, polypropylene, montmorillonite
Funding: This study was supported by the Ministry of Education of the Russian Federation as а part of the Government Assignment (project No. VRFY-2023-0005).
For citation: Karulina E. A., Volgina E. A., Kulemina S. M., Galikhanov M. F., Minzagirova A. M., The effect of the montmorillonite-based filler on the electret properties of polypropylene, St. Petersburg State Polytechnical University Journal. Physics and Mathematics. 17 (1) (2024) 29-37. DOI: https://doi.org/10.18721/JPM.17103
This is an open access article under the CC BY-NC 4.0 license (https://creativecommons. org/licenses/by-nc/4.0/)
Научная статья УДК 538.9
DOI: https://doi.org/10.18721/JPM.17103
ВЛИЯНИЕ НАПОЛНИТЕЛЯ НА ОСНОВЕ МОНТМОРИЛЛОНИТА НА ЭЛЕКТРЕТНЫЕ СВОЙСТВА ПОЛИПРОПИЛЕНА Е. А. Карулина 1 п, Е. А. Волгина 1, С. М. Кулемина 1,
М. Ф. Галиханов 23, А. М. Минзагирова 3 1 Российским государственный педагогическим университет им. А. И. Герцена, Санкт-Петербург, Россия;
2 Институт прикладных исследований Академии наук Республики Татарстан,
г. Казань, Республика Татарстан, Россия;
3 Казанским национальным исследовательским технологическим университет,
г. Казань, Республика Татарстан, Россия и [email protected]
© Karulina E. A., Volgina E. A., Kulemina S. M., Galikhanov M. F., Minzagirova A. M., 2024. Published by Peter the Great St. Petersburg Polytechnic University.
Аннотация. Проведены исследования электретных свойств полипропилена с различным процентным содержанием монтмориллонита методами термостимулированной релаксации потенциала и термостимулированных токов короткого замыкания. Выявлено заметное влияние концентрации наполнителя на стабильность электретного состояния. Определены параметры электрически активных дефектов и время хранения электретного состояния для разного содержания наполнителя в образцах. Установлено, что наилучшими электретными свойствами обладает полипропилен с 4 %-м массовым содержанием монтмориллонита.
Ключевые слова: электрет, полимерный композитный материал, электретное состояние, полипропилен, монтмориллонит
Финансирование: Исследование выполнено при финансовой поддержке Министерства образования Российской Федерации как часть Государственного задания (проект № VRFY-2023-0005).
Для цитирования: Карулина Е. А., Волгина Е. А., Кулемина С. М., Галиха-нов М. Ф., Минзагирова А. М. Влияние наполнителя на основе монтмориллонита на электретные свойства полипропилена // Научно-технические ведомости СПбГПУ. Физико-математические науки. 2024. Т. 17. № 1. С 29—37. DOI: https://doi.org/10.18721/ JPM.17103
Статья открытого доступа, распространяемая по лицензии CC BY-NC 4.0 (https:// creativecommons.org/licenses/by-nc/4.0/)
Introduction
The field of application of polymer electrets is quite wide: electroacoustics, medicine, filtering devices, radioactive radiation sensors, etc. [1].
An important parameter for the practical use of a polymer as an electret material is the stability of the electret state formed in it [2]. The influence of the electret electric field on microorganisms and bacteria is described in Refs. [3, 4]. It has been found that the effect of the field on microorganisms leads to a slowdown in the processes of their vital activity and can significantly increase the shelf life of food products.
Currently, an effective and technologically advanced way to form a stable electret charge in polymer films is the method of charging films in a corona discharge.
Promising objects of research are polymer films based on polypropylene (PP). Low density, high mechanical strength and resistance to chemical influences, as well as low cost make polypropylene a popular and easily accessible material.
It is known that the addition of dispersed fillers to the polymer matrix has a positive effect on the stability of the electret state in the polymer under study. This leads to the creation of new materials with improved electret properties and opens up new possibilities for their application [5, 6].
The results of studies [7, 8] have shown that the introduction of fillers such as diatomite and aerosil into the polyethylene matrix significantly increases the stability of the electret state, while pure polypropylene does not exhibit its high stability. Another possible filler in the polypropylene matrix is montmorillonite (MM). Montmorillonite is a cheap material with sorption properties.
Previous studies [9 — 12] have shown that the introduction of montmorillonite has a significant effect on the complex properties of polymers. For example, when chrysotile or montmorillonite is added to the polymer matrix, it leads to a significant change in the electrophysical properties of the starting material. The hydrophilicity of the fillers used may be one of the reasons for this. In Ref. [13], it was shown that the addition of montmorillonite particles to chitosan increased the activation energy of the electrical conductivity of this material from 0.20 eV to 0.31 eV, and as a result, the specific electrical conductivity of this polymer decreased by reducing the concentration of free ions.
In this regard, the goal of this study was to introduce montmorillonite into polypropylene films and investigate the filler effect on the electret properties of the modified material.
© Карулина Е. А., Волгина Е. А., Кулемина С. М., Галиханов М. Ф., Минзагирова А. М., 2024. Издатель: Санкт-Петербургский политехнический университет Петра Великого.
Materials and methods
In this work, the initial polypropylene films of the PP4215M brand (EP1X35F) and composite films based on it have been studied.
Composites based on PP with 2 and 4 wt.% of montmorillonite were prepared in the melt at the laboratory station "Plastograph EC" of the company "Brabender" (Germany) with adjustable electric heating at a temperature of 190°C and rotor speeds of 50 — 150 rpm for 300 s. The samples were produced by pressing on a GotechGT-7014-H10C hydraulic press at 190 ± 5°C with a heating time of 5 min, a pressure exposure of 3 min, and subsequent cooling of 3 min. The sample thickness of the initial films and composites varied from 0.12 ± 0.05 to 0.14 ± 0.05 mm.
Montmorillonite (mark 15A) is a clay mineral belonging to a subclass of layered silicates. The three-layer structure of this mineral, consisting of two silicon-oxygen and one aluminum hydroxide layers, is provided due to sufficiently weak molecular bonds. As a result, water molecules can easily penetrate into the interlayer space, and the mineral itself has good sorption properties.
The electret properties of the samples were investigated by the following methods:
thermally stimulated relaxation of the surface potential (TSRSP),
thermally stimulated currents (TSC).
When studying the films by the TSRSP technique, the samples were pre-polarized in a corona discharge at a temperature of 80° C. Further, the temperature dependence of the surface potential in the linear heating mode was removed.
In the TSC procedure, polarization was carried out at room temperature also in a corona discharge. The result of the study was a graph of the depolarization current dependence on temperature. The maximal temperature positions of the thermally stimulated depolarization currents and the nature of the TSD curves made it possible to determine the activation energy and the effective frequency factor of electrically active defects, as well as to obtain information about the relaxation mechanisms of the objects under study.
Results and discussion
Fig. 1,a presents the dependences of the surface potential decay on temperature at a heating rate of 5°C/min for PP samples without filler charged in the field of positive and negative corona discharges.
From this graphs we notice that the decreasing curves of the surface potential at different polarities of the polarizing field turn out to be identical. This result indicates that the relaxation process of the charge state is associated either with the reorientation of the dipoles in the samples or with the neutralization of the trapped charge due to the intrinsic conductivity of the polymer [14].
/•Л /VI
montmorillonite (MM) charged composite films (b); they were treated in the field of positive and negative corona discharges in both cases (a heating rate was 5°C/min)
Fig. 1,b shows the similar dependences of the surface potential decay but for samples PP + 4 % MM charged in the same fields. In this case, the decline of the surface potential becomes strongly dependent on the polarity of the corona discharge. The process of surface potential decay for samples charged in the positive corona discharge field is more intense than that for samples charged in the negative one. It can be assumed that in this case, sufficiently deep electronegative traps are formed at the polymer-filler interface. A similar effect was observed in polyethylene films filled with talc [15], simultaneously with a decrease in the conductivity of the polymer due to the sorption properties of the filler [16].
An additional confirmation of the above-mentioned double effect of the hydrophilic filler on the charge relaxation in the polypropylene is the temperature dependences of the current for PP films with different percentages of MM, pre-polarized in the negative corona discharge field at room temperature (Fig. 2).
Fig. 2. Thermostimulated currents for the initial films, composite films PP + n MM (n = 2 and 4 % by weight), polarized in the field of the negative corona discharge field (a heating rate was 9°C/min)
Here the intensity of the TST peaks grows significantly with an increase in the percentage of filler from 2 to 4 % (not proportional to the percentage), which can be explained not only by an increase in the quantity of traps at the polymer — montmorillonite boundary, but also by a decrease in the conductivity of the polymer.
The activation energy and frequency factor of the electrically active defects responsible for relaxation processes in both the initial and filled polymer samples were calculated using the method of varying the heating rate. As an example, Fig. 3,a,b shows the TSC curves for two heating rates for the initial PP films and PP ones with 4% of the filler mass.
(4 % by weight) (a) and the initial polypropylene films (b) polarized in the negative corona discharge field at different linear heating rates (6 and 9°C /min)
The formula for finding the activation energy W of relaxers by the temperature positions of the peaks at two heating rates has the form:
W =
kTmTmi втт
T - T В T
±m m 2* m,
2
(1)
where T, Tm2 are the temperature values of the maximal currents; P,, P2 are the heating rates; к is the Boltzmann constant.
The value of the frequency factor ю was determined by the following formula:
ш =
W p
exp
( w Л
(2)
where Tm is the temperature of the maximal current at the heating rate p.
The calculation results show an increase in the activation energy W for the composite polymer compared to the initial one from 0.75 ± 0.05 to 1.01 ± 0.05 eV at a frequency factor ю of the order of 1011 s-1. Obviously, such results should increase the relaxation time т of the electret state in the MM-filled polymer compared to the initial one.
Indeed, calculated the relaxation time of the electret state by the formula
т
p
1
exp
ш
( w Л
(3)
at room temperature, increases from 4 min (for PP without filler) to 256 hrs (for PP + 4% MM).
The temporary stability rise of the electret state when filling polypropylene with montmorillonite is accompanied by an increase in temperature stability. The temperature dependences of the surface potential in relative units for samples with different percentages of montmorillonite charged in the negative corona discharge field are shown in Fig. 4.
Fig. 4. Temperature dependences of the surface potential for PP films and PP + n MM (n = 2 and 4 % by weight) composite films charged in the negative corona discharge field
Similarly, according to the current spectroscopy data presented in Fig. 2, a significant change in the decline of the surface potential with an increase in temperature occurs when 4 wt. % MM is added., as well as the curve at 2 wt.% of the thermally stimulated relaxation of the potential almost coincides with a similar dependence for the initial polypropylene.
Conclusion
The electret properties of the initial polypropylene films and composite polypropylene ones with montmorillonite filler were studied by the TSRP and TSC methods.
It was revealed that the stability of the electret state increases compared to the initial PP with an increase in the percentage of montmorillonite to 4 wt.% in polypropylene films. This results from two reasons: the formation of sufficiently deep charge traps at the polymer-filler interface and a decrease in the conductivity of the polymer due to the sorption properties of the MMT filler.
The relaxation time of the electret state in the PP films with 4 wt.% of montmorillonite is about 256 hrs at room temperature; this result makes it possible to use these composite polymer films as an active packaging material for food products.
Further studies of the electret properties of polypropylene with a high percentage of montmorillonite will allow us to determine the optimal percentage of the filler.
REFERENCES
1. Boitsov V., Rychkov D., Polymeric electrets in innovative technologies, Izvestia: Herzen University Journal of Humanities & Sciences. (2 (4)) (2002) 118-132 (in Russian).
2. Rychkov A., Rychkov D., Trifonov S., Electret state stability in polymers with modified surface, Izvestia: Herzen University Journal of Humanities & Sciences. (4 (8)) (2004) 122-134 (in Russian).
3. Krynitskaya A. Y., Borisova A. N., Galikhanov M. F., et al., Influence of "active" packing material on development of microorganisms in foodstuff, Food Processing Industry. (1) (2011) 27-29 (in Russian).
4. Galikhanov M., Guzhova A., Borisova A., Effect of active packaging material on milk quality, Bulgar. Chem. Commun. 46 (Jan) (2014) 142-145.
5. Gorokhovatsky Yu., Aniskina L., Burda V., et al., On the nature of the electret state in composite low-density films of polyethylene with nano-dispersed SiO2 fillers, Izvestia: Herzen University Journal of Humanities & Sciences. (95) (2009) 63-67 (in Russian).
6. Temnov D., Fomicheva E., The dependence of the electret state stability of the polypropylene films on the share of the disperse filler (aerosil), Izvestia: Herzen University Journal of Humanities & Sciences. (135) (2010) 92-100 (in Russian).
7. Gorokhovatsky Yu. A., Demidova N. S., Temnov D. E., Electric charge relaxation in the polyethylene with mineral inclusions of diatomite, St. Petersburg Polytechnic University Journal. Physics and Mathematics. 13 (2) (2020) 9-16.
8. Ignatyeva D., Karulina E., Chistyakova O., The mechanism of electret state relaxation in polyactide films containing dispersed filler, Izvestia: Herzen University Journal of Humanities & Sciences. (173) (2015) 39-45 (in Russian).
9. Bobritskaia E., Temnov D., Chitosan as a material for tissue engineering, The Scientific Opinion. (3) (2013) 206-211 (in Russian).
10. Galikhanov M. F., Minzagirova A. M., Spiridonova R. R., Modifying the properties of polyethylene electrets through the incorporation of montmorillonite, Surf. Eng. Appl. Electrochem. 55 (6) (2019) 679-683.
11. Minzagirova A. M., Galikhanov M. F., Spiridonova R. R., et al., Effect of montmorillonite on the properties of polyethylene electret, AIP Conf. Proc. 2174 (Dec. 06) (2019) 020041.
12. Bobritskaya E., Kubrakova E., Temnov D., Fomicheva E., Electric relaxation in chitosan films with mineral nanodimentional inclusions, Izvestia: Herzen University Journal of Humanities & Sciences. (154) (2013) 69-76 (in Russian).
13. Bobritskaya E. I., Kastro R. A., Temnov D. E., Thermoactivation and dielectric spectroscopy of chitosan films, Physics of the Solid State. 55 (1) (2013) 225-228 (in Russian).
14. Gorokhovatski Yu., Temnov D., Thermally stimulated relaxation of surface potential and thermally stimulated short circuit currents in the charged dilectric, Izvestia: Herzen University Journal of Humanities & Sciences. (8(38)) (2007) 24-34 (in Russian).
15. Temnov D. E., Fomicheva E. E., Stozharov V. M., Vliyaniye talka na elektretnyye svoystva i strukturu polietilena vysokogo davleniya [The effect of talc on electret properties and the structure of high-pressure polyethylene], Herald of Kazan Technological University. (14) (2014) 321-323 (in Russian).
16. Galikhanov M., Gorokhovatskiy Yu., Gulyakova A., et al., The investigation of electret state stability in composite polymer films with dispersed filler, Izvestia: Herzen University Journal of Humanities & Sciences. (138) (2011) 25—34 (in Russian).
СПИСОК ЛИТЕРАТУРЫ
1. Бойцов В. Г., Рычков Д. А. Полимерные электреты в инновационных технологиях // Известия Российского государственного педагогического университета им. А. И. Герцена. 2002. № 2 (4). С. 118-132.
2. Рычков А. А., Рычков Д. А., Трифонов С. А. Стабильность электретного состояния в полимерах с модифицированной поверхностью // Известия Российского государственного педагогического университета им. А. И. Герцена. 2004. № 4 (8). С. 122-134.
3. Крыницкая А. Ю., Борисова А. Н., Галиханов М. Ф., Сысоева М. А., Гамаюрова В. С. Влияние «активного» упаковочного материала на развитие микроорганизмов в пищевых продуктах // Пищевая промышленность. 2011. № 1. С. 27-29.
4. Galikhanov M., Guzhova A., Borisova A. Effect of active packaging material on milk quality // Bulgarian Chemical Communications. 2014. Vol. 46. January. Pp. 142-145.
5. Гороховатский Ю. А., Анискина Л. Б., Бурда В. В., Галиханов М. Ф., Гороховатский И. Ю., Тазенков Б. А., Чистякова О. В. О природе электретного состояния в композитных пленках полиэтилена высокого давления с нанодисперсными наполнителями Si02 // Известия Российского государственного педагогического университета им. А. И. Герцена. 2009. № 95. С. 63-77.
6. Темнов Д., Фомичева Е. Стабильность электретного состояния пленок полипропилена в зависимости от содержания дисперсного наполнителя (аэросил) // Известия Российского государственного педагогического университета им. А. И. Герцена. 2010. № 135. С. 92—100.
7. Gorokhovatsky Yu. A., Demidova N. S., Temnov D. E., Electric charge relaxation in the polyethylene with mineral inclusions of diatomite // St. Petersburg Polytechnic University Journal. Physics and Mathematics. 2020. Vol. 13. No. 2. Pp. 9-16.
8. Игнатьева, Д. А., Карулина, Е. А., Чистякова О. В. Механизм релаксации электретного состояния в пленках полилактида с дисперсным наполнителем // Известия Российского государственного педагогического университета им. А. И. Герцена. 2015. № 173. С. 39-45.
9. Бобрицкая Е., Темнов Д. Хитозан - материал для тканевой инженерии // Научное мнение. 2013. № 3. С. 206—211.
10. Galikhanov M. F., Minzagirova A. M., Spiridonova R. R. Modifying the properties of polyethylene electrets through the incorporation of montmorillonite // Surface Engineering and Applied Electrochemistry. 2019. Vol. 55. No. 6. Pp. 679-683.
11. Minzagirova A. M., Galikhanov M. F., Spiridonova R. R., Khairyllin R. Z., Spiridonova A. O.
Effect of montmorillonite on the properties of polyethylene electret // AIP Conference Proceedings. 2019. Vol. 2174. December 06. P. 020041.
12. Бобрицкая Е. И., Кубракова Е. С., Темнов Д. Э., Фомичева Е. Е. Процессы электрической релаксации в пленках хитозана с минеральными наноразмерными включениями // Известия Российского государственного педагогического университета им. А. И. Герцена. 2013. № 154. С. 69-76.
13. Бобрицкая Е. И., Кастро Р. А., Темнов Д. Э. Термоактивационная и диэлектрическая спектроскопия пленок хитозана. // Физика твердого тела. 2013. Т. 55. № 1. С. 193-196.
14. Гороховатский Ю. А., Темнов Д. Э. Термостимулированная релаксация поверхностного потенциала и термостимулированные токи короткого замыкания в предварительно заряженном диэлектрике // Известия Российского государственного педагогического университета им. А. И. Герцена. 2007. № 8 (38). С. 24-34.
15. Темнов Д. Э., Фомичева Е. Е., Стожаров В. М. Влияние талька на электретные свойства и структуру полиэтилена высокого давления // Вестник Казанского технологического университета. 2014. № 14. С. 321-323.
16. Галиханов М. Ф., Гороховатский Ю. А., Гулякова А. А., Темнов Д. Э., Фомичева Е. Е.
Исследование стабильности электретного состояния в композитных полимерных пленках с дисперсным наполнителем // Известия Российского государственного педагогического университета им. А. И. Герцена. 2011. № 138. С. 25-34.
THE AUTHORS
KARULINA Elena A.
Herzen State Pedagogical University of Russia 48 Moyka Emb., St. Petersburg, 191186, Russia [email protected] ORCID: 0000-0001-9604-4769
VOLGINA Elena A.
Herzen State Pedagogical University of Russia 48 Moyka Emb., St. Petersburg, 191186, Russia [email protected] ORCID: 0000-0002-1536-5841
KULEMINA Sofya M.
Herzen State Pedagogical University of Russia 48 Moyka Emb., St. Petersburg, 191186, Russia [email protected] ORCID: 0009-0002-3569-4981
GALIKHANOV Mansur F.
Institute of Applied Research of Tatarstan Academy of Sciences, Kazan National Research Technological University 20 Bauman St., Kazan, 420111, Russia [email protected] ORCID: 0000-0001-5647-1854
MINZAGIROVA Alsu M.
Kazan National Research Technological University
68 Karl Marx St., Kazan, Republic of Tatarstan, 420015, Russia
ORCID: 0000-0002-8859-5621
СВЕДЕНИЯ ОБ АВТОРАХ
КАРУЛИНА Елена Анатольевна — кандидат физико-математических наук, доцент кафедры общей и экспериментальной физики Российского государственного педагогического университета им. А. И. Герцена, Санкт-Петербург, Россия.
191186, Россия, г. Санкт-Петербург, наб. р. Мойки, 48
ORCID: 0000-0001-9604-4769
ВОЛГИНА Елена Алексеевна — ассистентка кафедры общей и экспериментальной физики Российского государственного педагогического университета им. А. И. Герцена, Санкт-Петербург, Россия.
191186, Россия, г. Санкт-Петербург, наб. р. Мойки, 48
ORCID: 0000-0002-1536-5841
КУЛЕМИНА Софья Михайловна — аспирантка кафедры общей и экспериментальной физики Российского государственного педагогического университета им. А. И. Герцена, Санкт-Петербург, Россия.
191186, Россия, г. Санкт-Петербург, наб. р. Мойки, 48
ORCID: 0009-0002-3569-4981
ГАЛИХАНОВ Мансур Флоридович — доктор технических наук, ведущий научный сотрудник Центра новых материалов и перспективных технологий Института прикладных исследований Академии наук Республики Татарстан; профессор кафедры технологии переработки полимеров и композиционных материалов Казанского национального исследовательского технологического университета г. Казань, Республика Татарстан, Россия.
420111, Россия, г. Казань, ул. Баумана, 20
ORCID: 0000-0001-5647-1854
МИНЗАГИРОВА Алсу Мударрисовна — аспирантка кафедры технологии переработки полимеров и композиционных материалов Казанского национального исследовательского технологического университета, г. Казань, Республика Татарстан, Россия.
420015, Россия, Республика Татарстан, г. Казань, ул. К. Маркса, 68
ORCID: 0000-0002-8859-5621
Received 29.11.2023. Approved after reviewing 14.12.2023. Accepted 14.12.2023.
Статья поступила в редакцию 29.11.2023. Одобрена после рецензирования 14.12.2023. Принята 14.12.2023.
© Санкт-Петербургский политехнический университет Петра Великого, 2024
