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262 CHEMICAL PROBLEMS 2023 no. 3 (21) ISSN 2221-8688
UDC 678.072
USE OF GLYCIDYLOXYMETHYL SUBSTITUTED PHENYL (BENZYL) CYCLOPROPANES IN THE COMPOSITION OF EPOXIDE OLIGOMER ED-20 AS
DILUENTS
1E.N. Ahmadov, 1P.M. Shirinov, 2R.Z. Shahnazarli, 1G.A. Ramazanov
1Sumgait State University, 43-rd quarter, Sumgait, AZ 5008, Azerbaijan Republic, 2Institute of Polymer Materials under the Ministry of Science and Education of the Republic ofAzerbaijan S.Vurgun Str., 124, Sumgait AZ 5004, Azerbaijan Republic; e-mail: [email protected]
Received 19.05.2023 Accepted 13.08.2023
Abstract: By the interaction of phenyl (benzyl) substituted cyclopropylcarbinols with epichlorohydrin, the glycidyloxymethyl substituted phenyl(benzyl)cyclopropanes, used as active diluents of epoxide resin ED-20, were synthesized. It found that the addition of the obtained epoxy compounds to the epoxide resin decreases the viscosity of the resin and increases the lifetime of the compositions. The high degree of curing (96-98%) indicates the participation of the synthesized epoxycyclopropanes in the cross-linking processes. Some physical-mechanical characteristics of compounds made with the participation of the synthesized epoxycyclopropanes were established. The improvement of strength and heat-physical parameters of cured compositions in comparison with compositions made without diluents was revealed.
Keywords: glycidyloxymethyl substituted phenyl (benzyl) cyclopropanes, epoxide composition, modification, active diluents, curing.
DOI: 10.32737/2221-8688-2023-3-262-268
Introduction
The epoxide compositions are perspective materials widely used in such industries as construction, instrument-making, automobile industry, electrical engineering, etc. The epoxide resins are used in impregnating and filling compounds, for preparation of coatings meeting the corresponding operational requirements, etc [1-5]. The advantages of the epoxide resins are their mechanical and chemical resistance, high dielectric characteristics after curing, low shrinkage, excellent adhesion to metals, glass, wood and a number of other materials. The epoxide resins are easily combined with many polymers and oligomers, which are used to change some of their properties [6-8]. However, along with the positive properties, the epoxide resins of ED-20 type have a number of disadvantages, which include high viscosity, high exothermic effect
during their curing, as well as a short viability time. The epoxide compositions have a certain lifetime, after which they undergo the cross-linking, forming a net structure. The obtained materials with three-dimensional cross-linked structure are not dissolved and incapable of further processing. For elimination of these disadvantages, the modifiers - active or inactive diluents decreasing their viscosity and the temperature of the exothermic reaction, and also prolonging the viability of the composition are usually introduced into the composition of the epoxide resins [9-10]. Therefore, the development of methods for directional regulation of the properties of epoxide compositions by their modification with various additives plays a particular importance and actuality.
CHEMICAL PROBLEMS 2023 no. 3 (21)
www.chemprob.org
This work has been devoted to the
investigation of modification of the properties
of the epoxide resin ED-20 with the use of
glycidyloxymethyl substituted
phenyl(benzyl)cyclopropanes as diluents and study into the properties of the cured compounds.
Experimental part
The synthesis of glycidyloxymethyl substituted phenyl (benzyl) cyclopropanes was carried out in keeping with the methodology described in work [11].
Modification of ED-20 with glycidyloxymethyl substituted
phenyl(benzyl)cyclopropanes. 5-15 mass p. of glycidyloxymethyl substituted phenyl (benzyl) cyclopropane as a diluent and the calculated quantity of curing agent of polyethylene polyamine (PEPA) was added to 100 mass p. of epoxide resin of ED-20 type with stirring. Then the obtained mixture was stirred to a homogeneous mass for removal of air bubbles, the mixture was evacuated at 25-30 °C and the reaction mass was poured into specially prepared molds for curing.
Curing of compositions on the basis of ED-20 was carried out in the presence of PEPA,
the content of which was calculated according to the known formula based on epoxide number values. The following curing regime of the prepared compositions was selected by preliminary experiments: 16 h. - at room temperature; for 2 h - at 60°C, 2 h - at 80°C and 2 h - at 120°C.
The degree of cross-linking and the content of gel- and sol-fractions of the cured compositions were determined by extraction with acetone in Soxlet apparatus during the day, with the subsequent drying to a constant mass.
The conditional viscosity of the resin was determined using a ball viscometer (d=2.37 mm) at temperature 75°C.
The adhesion strength of the glues during shear was determined in accordance with GOST 14759-69.
Results and discussion
With the aim of decreasing the viscosity and improving the recyclability of high-viscous epoxide resins, as well as the elongation of the lifetime of compositions based on them, the resins are usually subjected to dilution (modification) with low-viscous chemically active compounds containing epoxide groups. With that end in view, there were synthesized the glycidyloxymethyl substituted
phenyl(benzyl)cyclopropanes 1-3, which are used in the composition of epoxide resin ED-20
as active diluents. In our previous investigations, we have carried out a similar modification of the epoxide resin for decrease of its viscosity by means of glycidyloxycarbonyl substituted phenyl (benzyl) cyclopropanes obtained from phenyl (benzyl) substituted cyclopropancarboxylic acids [12].
The compounds 1-3 were obtained by the interaction of phenyl (benzyl) substituted cyclopropylcarbinols with epichlorohydrin, according to the scheme below:
R1=Ph; R2=H (1) R1=Ph-CH2; R2=H (2) R'=Ph-CH2; RZ=CH3 (3)
|l=Pl,.rn T>2=
^Pii-ru - p2=r
Some physical-chemical parameters of phenyl(benzyl)cyclopropanes are presented in glycidyloxymethyl substituted Table 1.
As is known, the rheological properties of solutions depend on the type of intermolecular interaction. When it comes to the epoxide resin ED-20, the intermolecular interactions stipulate the formation of associates. When introducing active diluents into the composition of the
epoxide resin, these associates are destroyed. Therefore, it is necessary to find out firstly the optimal quantity of diluent in the composition, in which the less stable associates with low viscosity are formed.
Table 1. Some physical-chemical indices of glycidyloxymethyl substituted phenyl (benzyl)
cyclopropanes.
Code of comp ounds R1 R2 MM Bp., °C/mm.merc. c. d20 4 < u, % Content of epoxide groups* (found/calc.)
1 Ph- H 204 112-118/4 1.1206 1.5210 86 27.82 / 27.94
2 PhCH2- H 218 119-122/4 1.1100 1.5180 83 25.96 / 26.15
3 PhCH2- CH3 232 126-129/4 1.1060 1.5090 78 24.24 / 24.57
ED-20 - - 380 - 1.1680 1.5611 - 22.60
- per the propylene oxide group (carried out according to GOST
2497-78, sec.3).
The compounds used by us as active diluents and simultaneously modifiers of some properties of the cured compounds are monoepoxide compounds. Since the epoxide groups participate primarily in the cross-linking process with appropriate curing agents, such monoepoxide compounds should be considered as agents breaking the chain, due to that a deterioration of the properties of the cured compositions occurs.
In the structure of the synthesized compounds, along with the epoxide functional groups, there are three-membered cycles and
other functional groups. As is known, the cyclopropane ring is a stressed cycle and in its opening, a large quantity of heat is isolated and the appearance of additional chemical bonds increasing the cross-linking density.
It revealed that the synthesized compounds 1-3 are well combined with epoxide resin and essentially reduce its viscosity. So, when introducing the compounds 1-3 into the structure of the composition in a quantity from 5 to 15 mass p. (per 100 mass p. of the epoxide resin), the conditional viscosity of the initial resin is dropped from 30 to 15 (Table 2).
Table 2. Influence of the content of compounds 1-3 on the viscosity and lifetime of compositions.
Indices ED-20 Composition of resin ED-20 with compounds (mass p.)
1 2 3
5 10 15 5 10 15 5 10 15
Conditional viscosity *, sec. 30 21 18 15 22 19 17 25 21 19
Lifetime** at 25°C, min. 40 68 72 77 76 79 82 79 84 88
*
* - determined on a ball viscometer (d=2.37 mm) at 75°C;
** - determined on the change of the epoxide number of the composition.
In Fig.1 the dependence of the relative viscosity (the ratio of the conditional viscosity of resin ED-20 with diluent for the conditional viscosity of pure resin) of resin ED-20 on the content of diluent - compounds 1-3 is shown.
The data presented in Fig. 1 show that an increase of the diluents content from 5 mass p. to 15 mass p. leads to the fact that the relative viscosity of the system is decreased in 1.2-2.7 times.
It is known that the composition of the epoxide resins primarily influences on their lifetime, and also on the compositions based on them. When using the compounds 1-3 in the structure of compositions, along with the decrease of the system, the increase of the lifetime of the composition was revealed. In Table 2 the influence of the active diluent content on the lifetime of the compositions is shown.
During compositions, was observed,
the curing of the prepared the increase of the curing rate and the compositions with the
participation of the compound 1 was cured faster (within 25-30 min.) than those with the compounds 2 and 3 (30-45 min.).
o
<N i
q
w
<D
3
O <N i
q
w
5 10 15
Diluent content, mass p.
Fig.1. Dependence of the relative viscosity of the compositions "t" on the diluent content: 1 - ED-20+compound 1; 2 - ED-20+ compound 2; 3 - ED-20+ compound 3.
The degree of curing of the compositions was established by acetone extraction of the samples in a Soxlet apparatus. The obtained results showed that the curing of these compounds reached 96-98%, which indicates the participation of the compounds 1-3 in the cross-linking processes. Moreover, the cross-
linking reactions proceed due to the opening of both epoxide groups and cyclopropane fragments, which was observed in the disappearance of the characteristic absorption bands of the cyclopropane group (at 1035 cm-1) in the IR spectra of the cured compositions (Fig. 2).
Fig. 2. IR spectrum of the cured composition on the basis of ED-20 and compound 1.
The use of phenyl (benzyl) substituted epoxycyclopropanes in the composition of ED-20 leads to an increase in the net density and, in
this connection, to an increase of the strength indices of the compounds, heat- and thermal stability and other characteristics (Table 3).
Table 3. Some physical-mechanical properties of the cured compositions on the basis of resin ED-20 with diluents 1-3 (curing agent - PEPA - 10 mass p. per 100 mass p. of resin)
Indices ED-20 Composition of resin ED-20 with com pounds (mass p.)
1 2 3
5 10 15 5 10 15 5 10 15
Destructive tensile stress, MPa 40.1 77.8 79.2 80.7 75.0 76.3 77.6 69.1 70.6 71.8
Adhesion strength, MPa 8.2 9.5 9.6 9.8 9.4 9.4 9.5 8.8 8.9 8.9
Continuation of Table 3.
Brinell hardness, MPa 13.3 12.4 12.8 12.9 12.9 13.3 13.5 13.2 13.8 14.6
Vicat heat-resistance, °C 98 137 139 143 138 139 142 138 138 140
Softening temperature, °C 127 298 349 373 278 322 333 250 280 302
Water absorption, % 1.2 1.1 1.1 1.0 1.1 0.9 0.9 0.8 0.8 0.6
There is also observed an increase in the heat resistance values. With an increase of the content of the active diluent, the softening temperatures of the compounds are increased as well. Moreover, such increase becomes quite
400 -,
noticeable at low (up to 10 mass p.) diluent concentrations, at diluent content 15^20 mass p. the softening temperatures are not essentially changed (Fig. 3).
(U
!-h !-h
(U CP
s
<K o
GO
350
300
250
10 15
Diluents content, mass p.
Fig. 3. Dependence of softening temperature of the cured compositions on diluent content in the composition of resin ED-20: 1 - compound 1; 2 - compound 2; 3 - compound 3.
By the interaction of phenyl (benzyl) substituted cyclopropyl carbinols with epichlorohydrin, the glycidyloxymethyl substituted phenyl (benzyl) cyclopropanes, used in the structure of epoxide compositions on the basis of ED-20 resin as reactive diluents were synthesized and characterized. The tests showed that their introduction into the composition of the resin ED-20 leads to a drop in the viscosity and an increase in the lifetime of the compositions.
The obtained results showed that some
characteristics of the cured compositions of PEPA with the use of phenyl (benzyl) substituted epoxycyclopropanes are improved. In particular, it is observed an increase of the tensile strength and an increase of the heat resistance of the compositions. Such increase of indices of the cured compounds was probably due to the fact that the used diluents, along with epoxide groups, also contain cyclopropane fragments in their molecules, which also participate in the cross-linking processes.
References
1. Kumara R., Kumarb K., Sahooc O., Bhowmika S. Study of mechanical properties of wood dust reinforced epoxy composite. Procedia Materials Science. 2014, no. 6, pp. 551-556.
2. Osipov P.V., Osipchik V.S., Smotrova S.A., Savelyev D.N. Regulation of the properties of filled epoxide oligomers. Plastic masses. 2011, no. 4, pp. 3-5. (In Russian).
3. Stukhlyak P.D., Kartashov V.V., Sorivka I.T., Skorokhod F.Z. The influence of ferromagnetic fillers on the impact viscosity and sedimentation resistance of epoxycomposites formed under the action of an alternating magnetic field. Perspective materials. 2013, no. 6. pp. 63-68. (In Russian).
4. Starokadomsky D.L., Tkachenko A.A., Garashenko I.I. Changing the properties of the polyepoxide-nanosilicon composite after modification of the filler surface with the initial epoxide resin. Plastic masses. 2015, no. 5-6. pp. 50-55. (In Russian).
5. Ragimova A.A., Mamedov E.D. Preparation of epoxide ED-20-based composition materials. Chemical Problems. 2020. vol.18, no 1, pp. 118-123.
6. Eremeeva N.M., Nikiforov A.V., Sveshnikova E.S., Panova L.G. Study of the properties of epoxy compositions based on modified cellulose-containing materials. Young scientist. 2015. no. 24.1(104.1), pp. 20-23. (In Russian).
7. Mostovoy A.S., Plakunova E.V., Panova L.G.
Development of fire-resistant epoxide compositions and investigation of their structure and properties. Perspective materials. 2014, no. 1, pp. 37-43. (In Russian).
8. Shirshova E.S., Tatarintseva E.A., Plakunova E.V., Panova L.G. Study of the influence of modifiers on the properties of the epoxide compositions. Plastic masses. 2006, no. 12, pp. 34-36. (In Russian).
9. Mostovoy A.S., Yakovlev E.A., Burmistrov i.N., Panova L.G. Use of Modified Nanoparticles of Potassium Polytitanate and Physical Methods of Modification of Epoxy Composition for Improving Their Operational Properties. Russian Journal of Applied Chemistry. 2015, vol. 88, no. 1, pp. 129-137.
10. Sadykov Sh.F., Ishenko N.Ya., Agaeva S.A. Modification of ED-20 by glycide esters of some benzoic acids. Plastic masses. 2008, no. 3, pp. 24-26. (In Russian).
11. Ahmadov E.N., Ramazanov G.A., Shahnazarli R.Z., Guliyev A.M. Synthesis and study of stabilizing action in PVC of glycidyl esters of phenyl(benzyl)cyclopropyl carbinols. European Journal of Analytical and Applied Chemistry. 2016, no. 2. pp. 3-8.
12. Ahmadov E.N., Shahnazarli R.Z., Ramazanov G.A., Guliyev A.M. Synthesis and study of the influence of epoxycyclopropanes on the properties of epoxide compositions. Chemical Problems. 2016. vol.14, no 1, pp. 36-43.
QLiSiDiLOKSiMETiL 8V8ZLi FENiL (BENZiL) TSiKLOPROPANLARIN ED-20 EPOKSiD OLÎQOMERÎNÎN T9RKÎBÎND9 DURULAÇDIRICI KÎMi ÎSTiFADOSi
1E.N. ahmadov, 1 P.M. Çirinov, 2R.Z. Çahnazarli, 1Q.9. Ramazanov
1Sumqayit Dôvlat Universiteti, AZ 5008, Sumqayit, 43-cu mahalla 2Azarbaycan Respublikasi Elm va Tahsil Nazirliyi, Polimer Materiallari institutu AZ 5004 Sumqayit, S.Vurgun kuç., 124 e-mail: [email protected]
Xtilasa: Fenil (benzil) avazli tsiklopropilkarbinollann epixlorhidrinla qar§iliqli tasirindan qlisidiloksimetil avazli fenil (benzil) tsiklopropanlar sintez edilarak ED-20 epoksid oliqomerinin tarkibinda durula§dirici kimi istifada olunmu§dur. Muayyan edilmi§dir ki, sintez edilmi§ epoksibirla§malarin epoksid qatranina alava edilmasi ila qatranin ozluluyu azalir, kompozisiyanin isa ya§ama muddati artir. Hazirlanmi§ kompozisiyalarin barkima daracalari yuksak oldugu (96-98%) sintez edilmi§ birla§malarin tikilma prosesinda i§tirakini gostarir. Alinmi§ kompaundlarin birsira fiziki-mexaniki xarakteristikalari tayin edilmi§ va muayyan edilmi§dir ki, durula§diricinin i§tiraki ila barkidlmi§ kompozisiyalarin mohkamlik xarakteristikalari va istiya davamliliqlari muvafiq durula§diricisiz kompozisiyalarin gostaricilarindan nazara farpacaq daracada ustundur.
A^ar sozlar: qlisidiloksimetil avazli fenil(benzil)tsiklopropanlar, epoksid kompozisiyasi, modifikasiya, aktiv alava, durula§dirici, barkidilma.
ИСПОЛЬЗОВАНИЕ ГЛИЦИДИЛОКСИМЕТИЛЗАМЕЩЕННЫХ ФЕНИЛ(БЕНЗИЛ)ЦИКЛОПРОПАНОВ В СОСТАВЕ ЭПОКСИДНОГО ОЛИГОМЕРА ЭД-20 В КАЧЕСТВЕ РАЗБАВИТЕЛЕЙ
11 2 1 Э.Н. Ахмедов, П.М. Ширинов, Р.З. Шахназарли, Г.А. Рамазанов
1Сумгаитский Государственный Университет AZ 5008, Сумгаит, кв. 43 2Институт Полимерных Материалов Министерства Науки и Образования Азербайджанской Республики AZ 5004 Сумгайыт, ул С. Вургуна, 124 e-mail: elnurahmadov@mail. ru
Аннотация: Взаимодействием фенил(бензил)замещенных циклопропилкарбинолов с эпихлоргидрином синтезированы глицидилоксиметилзамещенные фенил(бензил) циклопропаны, которые были использованы в качестве активных разбавителей эпоксидной смолы ЭД -20. Установлено, что добавление полученных эпоксисоединений в эпоксидную смолу уменьшает вязкость смолы и увеличивает время жизни композиций. Высокая степень отверждения (96-98%) указывает на участие синтезированных эпоксициклопропанов в процессах сшивки. Определены некоторые физико-механические характеристики компаундов, изготовленных с участием синтезированных эпоксициклопропанов: выявлено улучшение прочностных и теплофизических показателей отвержденных композиций по сравнению с композициями, изготовленными без разбавителей.
Ключевые слова: глицидилоксиметилзамещенные фенил(бензил)циклопропаны, эпоксидная композиция, модификация, активный разбавитель, отверждение.
