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CHEMICAL PROBLEMS 2020 no. 4 (18) ISSN 2221-8688 457
UDC 547.678
EPOXY-CONTAINING ADDUCTS OF ROSIN ASLIGHT- AND THERMOSTABILIZERS
FOR PVC
1M.S. Pirguliyeva, 2A.M. Guliyev
1Sumgait State University AZ5008, Sumgait, 43rdquarter, e-mail: [email protected] 2Institute of Polymer Materials of the National Academy of Sciences of Azerbaijan, AZ5004, Sumgait, S.Vurgun Str., 124. e-mail: [email protected]
Received 27.09.2020 Accepted 30.11.2020
Abstract: The thermo- and light-stabilizing activity of glycidyloxycarbonyl- and glycidyloxymethyl-substituted derivatives of the sulphur-containing rosin in the compositions on the basis of plasticized polyvinyl chloride were studied. It found that the proposed epoxy-derivative adducts of rosin possess thermal stability allowing them to withstand the processing temperature of polyvinyl chloride compositions. The developments showed that the proposed stabilizers can protect the polymer matrix against light radiation. It revealed that the film samples prepared with the help of the proposed stabilizers showed the high thermal stability, impact resistance, good frost resistance and mechanical strength.
Keywords: rosin, polyvinyl chloride, epoxy-derivative, compositions, stabilizers, thermal stability, frost resistance
DOI: 10.32737/2221-8688-2020-4-457-463
Introduction
As it is known, the introduction of various number of advantages in comparison with additives such as plasticizers, stabilizers, known stabilizers such as stearates, silicates, antipyrenes, etc. into the composition materials basic lead salts, phosphates, etc. The epoxide is one of the main methods of adding specific compounds as HCl acceptors cause no turbidity properties thereto and improving physical- of the material, nor decrease electrical mechanical and technological parameters of properties of the compositions. They are noted materials [1-3]. Most synthetic polymers are for good compatibility with PVC, so in this case noted for sufficient stability in temperature, the compositions do not sweat. Thus, the light, atmospheric action, etc. However, this introduction of epoxy compounds into the cannot be referred to PVC which is easily composition of PVC-based compositions decomposed with HCl isolation in case of increases not only thermal, but also thermal-temperature and light influence [4]. oxidative stability and improves the physical
The epoxide compounds are widely used and mechanical properties of PVC products. as stabilizers for chlorine-containing The purpose of this investigation was to
polyolefins, in particular PVC. The use of prepare epoxy-derivatives of rosin and their epoxide compounds for PVC stabilization has a testing as co-stabilizers in the PVC composition.
Experimental
The synthesis of the sulphur-containing cadmium-zinc stabilizer (trademark Vigostat-
rosin (compounds 1 and 2) was presented in the BCC) was used as a stabilizer. Benazol-P was
work [5]. For preparation of the film materials, used as a light stabilizer.
the suspension PVC of mark S-7059-M was The films samples on the basis of
used. Dioctyl phthalate (DOPh) was used as a plasticized PVC containing stabilizers and bis-plasticizer. The mixture of equal quantities of adducts 1 and 2, suggested by us as co-calcium and zinc stearate and complex barium-
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CHEMICAL PROBLEMS 2020 no. 4 (18)
stabilizers were obtained by means of compositions rolling.
The PVC-based compositions with addition of synthesized bis-adducts were prepared by mixing components in the Brabender mixer. Then they were subjected to gelatinization and plasticization by keeping them in an oven at 90°C for 1.5-2.0 h. After that the rolling was produced at 150°C for 10 min., and then there was performed the pressing at the same temperature and pressure 5.0 MPa for 10 min. The cooling was carried out with water. The content of bis-adduct per 100 mass p. of PVC was 2 mass p. The composition mixtures were made both with the participation of calcium and barium stearates and without them.
The films of plasticized PVC containing the stabilizers synthesized by us were obtained
on rollers. The stabilizers were preliminarily dissolved and added to PVC. The mixture swelling was carried out in an oven at 110°C for 1 h. The plasticization was realized at 160° C on the rollers till preparation of a homogeneous mass. The films were obtained on a four-roll laboratory calender at roll temperature 150-165°C. The films thickness was 0.3±0.05 mm.
The thermo-gravimetric analysis of samples and initial products was carried out on Paulik-Paulik-Erdei derivatograph (heating rate - 5°C/min).
The light-warm aging of samples was carried out at temperature 70°C under lamp DPT-375 for 72 h (according to GOST 8979-75) [6]. The physical-mechanical parameters were determined on a tensile testing machine PM-30-1.
Results and discussion
In search of effective stabilizers, we worked out sulphur-containing epoxide compounds on the basis of accessible alternative raw material - rosin. The synthesis of intended adducts (compounds 1 and 2) was carried out by two methods [5]:
- preparation of glycidyl esters of rosin and its hydroxymethyl derivative with the subsequent
addition of ethanedithiol thereto under conditions of the radical initiation; - radical addition of ethanedithiol to rosin or its hydroxymethyl derivative with preparation of carboxyl- and hydroxyl-containing bis-adducts, then the synthesis of adducts of the appropriate glycidyl esters on their basis.
The glycidyl ester of rosin (as levopimaric acid) was obtained by means of the reaction of sodium salt of acid with epichlorohydrin. The reaction of glycidyl ester of levopimaric acid with ethanedithiol was carried out in the presence of AIBN at temperature 70°C for 60-
120 min. AIBN was taken in a quantity of 0.5 mass%, and the ratio of glycidyl ester of levopimaric acid to ethanedithiol was 2:1. The bis-adducts (compounds 1 and 2) were obtained with almost quantitative yields. According to a similar scheme, the bis-adduct (compound 2) -
EPOXY-CONTAINING ADDUCTS OF
459
glycidyloxymethyl derivative rosin was rosin. obtained from hydroxymethyl derivative of
,h
Me| |
H 'S
I | Me
S H
Me CH2OH \Q/\/°2HC Me
zS^cl
Using GPC analysis method, it found that the obtained adducts 1 and 2 are the individual compounds with MW=807 (calculated 810) and 778 (calculated 782), respectively. These compounds were low-viscous products that were easily dissolved in many organic solvents.
The epoxide compounds 1 and 2, containing tricyclic rosin fragments in a molecule, developed by us, are compatible with PVC, and as will be shown below, possess stabilizing properties.
The tests showed that the epoxide compounds worked out by us have higher thermal stability. Due to good compatibility
Me CH2Os/\ /
Me | |
H S
S H
with PVC, these compounds do not migrate to the surface of products made.
For estimation of the beginning (Tbegin.) and the final (Tend) temperatures of thermal decomposition of the samples and for calculation of the activation energy Ea of the thermal destruction process, we used TGA method (Table 1) [7]. To compare the obtained data with the data of industrial stabilizers, TGA-curves were taken for samples with the help of light stabilizers used: Benazol-P, thermostabilizer - calcium stearate and Vigostab-BCC.
Table 1. Thermal characteristics of sulphur-containing epoxy-derivatives of rosin and industrial
catalysts
Compound Results of thermal analysis
T T Tbesin.5 c T T Tend., c Eeff., kJ/mol
Compound 1 243 306 40.9
Compound 2 252 302 42.2
Vigostab-BCC 257 325 44.7
It follows from Table 1 that Tbegin. value of decomposition of the sulfur-containing epoxy derivatives of rosin (compounds 1 and 2) and known stabilizers used in industry have similar values, while Tend value of decomposition of these samples strongly differed. Moreover, the samples proposed by us have considerably higher values. This is evidenced by the value of their Eef. termodestruction. All this has probably been connected with structural peculiarities (polycyclic structure) of the proposed stabilizers.
For estimation of the possibility of the use of the synthesized compounds as thermo- and light-stabilizers, the compositions on the basis of PVC with the use of DOPh plasticizer (40
mass % per 100 mass % of PVC) had been prepared. The films made from these compositions were then subjected to the thermogravimetric analysis (Table 2). The obtained data show that the values of both Tbegin.and Tend increased when used as proposed additives. For estimation of the synthesized compounds as the light-stabilizers they were subjected to the accelerated light aging. Their efficiency was determined by values of stability coefficients on strength (K0) and relative elongation (Ke). These parameters were identified as the percentage of retention of composition properties after light-warm aging [8].
Table 2. Some thermal and physical-mechanical characteristics of films made with the participation of proposed and known stabilizers (PVC - 100 mass p, DOPh - 40 mass p, stabilizer - 2 mass p, co-stabilizer - 2 mass p.).
Stabilizer Results of thermal analysis Light-warm aging
t °r T begin., C Tend., C Eeff., kJ/mol K0, % K£, % *
Compound 1 197 282 116.2 0.99 1.09
Compound 2 202 296 113.6 1.04 1.02
Vigostab-BCC** 195 292 114.9 95.3 97.2
* - determined by [6];
** - data of works [8].
The test results showed that films made of PVC-compositions and stabilized by both the proposed compounds and standard stabilizers, after light-warm aging, in a case of using new additives, exceed the known ones. The
stabilizing action of the used compounds has been studied by determination of HCl quantity, isolating as a result of effect of high temperature or light on composition (Table 3) [9].
Table 3. Stabilizing capacity of epoxy-containing derivatives of rosin (quantity of co-stabilizer -_2.0 mass p. per 100 mass p. of PVC)._
Code of compounds MW Epoxide number, % found/calculated Loss temperature of 5% mass,°C* Time before beginning of HCl isolation at 175°C, min**
1 810 10.2 / 10.62 285 45
2 782 10.88 / 11.00 280 48
* - for compositions cured by PEPA [10]; ** - for composition without addition - 20 min.
It follows from the data in Table 3 that as the content of epoxide groups increased, their stabilizing action increased as well. In this case, the efficiency of the stabilizing action of the proposed compounds is determined by the starting temperature of decomposition (at the
defined heating rate) and the duration of induction period. The experiments showed that in all cases there is observed an availability of the induction period that is increased as the content of the epoxide groups increased and decreased with rise in temperature (Table 4).
Table 4. Influence of epoxy-containing derivatives of rosin on changes in the induction period and _decomposition temperature of the PVC-based compositions at various temperatures.
Induction period (time before beginning of HCl Decomposition
Composition isolai ion at temperature' , min temperature,
150°C 175°C 190°C °C
PVC 18 6 - 168
PVC + comp.1 64 43 8 187
PVC + comp.2 69 48 9 193
It should be noted that the stabilizing activity of adducts 1 and 2 has been connected with availability of the sulfur atoms and epoxide group in the molecules of these compounds,
easily reacting with HCl, isolated from PVC under action of temperature and light. Consequently, under the influence of the
EPOXY-CONTAINING ADDUCTS OF
461
epoxide additives, PVC dehydrochlorination rate falls sharply.
Compositions made on the basis of PVC with the use of epoxy-containing compounds 1
and 2, having sulfur atoms as sulfide bond along with epoxide groups in their composition, have higher impact resistance, good frost resistance and mechanical properties (Table 5).
Table 5. Some properties of the PVC-based compositions with the use of epoxy-derivatives of bis-
adduct of ethanedithiol with rosin
Components included in the composition on the basis of PVC
Name of index DOPh(40)* Calcium DOPh (40) DOPh (20) DOPh (40)
and barium Comp.1(2) Comp.2 (20)
stearate (2)
Tensile strength, MPa 19.6 19.8 19.6 19.0
Specific elongation at break, % 246 243 242 250
Tensile modulus of elasticity, MPa 11.8 11.7 11.6 11.8
Induction period at 170°C, min. 320 316 316 285
Frost resistance, °C -51 -52 -52 -50
Volatile, % (at 100°C, 1 h under vacuum) 0.29 0.26 0.20 0.31
Decomposition temperature, °C 293 290 292 286
*-the content in mass p. is indicated in parentheses.
The values identified in the physical-mechanical and other properties of the prepared compositions showed that tensile strength, specific elongation at break and modulus of elasticity at 100% deformation are at the level of indices of compositions made only with the participation of widely used plasticizer DOPh and stabilizers - calcium and barium stearates [11].
Thus, it revealed that the synthesized
epoxy-containing compounds in the composition of PVC-compositions show their stabilizing effect and can be used as stabilizers for PVC. It found that in this case the compositions made on the basis of PVC with the use of these compounds had relatively better indices in physical-mechanical properties as compared to indices of compositions made in the absence of these compounds.
References
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Polyvinyl chloride. 2007, 728 p.
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7. Shakhnazarli R.Z., Ishchenko N.Ya., Makarenko O.A., Guliev A.M. Free radical functionalization of polypropylene by
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vinyloxycyclopropanecarboxylic acid under conditions of reactive extrusion. Polimernye materialy i tehnologii. 2019, vol. 5, no. 1, pp. 26-32. (In Russian).
8. Kuvshinova S.A., Syrbu E.S., Novikov I.V. etc. Molecular anisotropic derivatives of phenyl benzoate as stabilizers of compositions based on plasticized polyvinyl chloride. The Russian Journal of Applied Chemistry. 2015, vol. 88, no. 2, pp. 325-331.
9. Folarin O.M., Sadiku E.R. Thermal stabilizers for poly(vinyl chloride): A
review. Int. J. Phys. Sci. 2011, vol. 6, no. 18, pp. 4323-4330.
10. Pirgulieva M.S. New curable rosin-based epoxy compounds. Proceedings of the VI International Scientific and Practical Conference "International innovation research". Russia, Penza, 2017, pp. 19-25.
11. Sabaa M.W., Mohamed R.R., Yassin A.A. Organic thermal stabilizers for rigid poly(vinyl chloride). Part X. N-acryloyl-N'-^-substituted phenylthiourea derivatives. J. Polym. Degrad. Stab. 2003, vol. 82, no. 3, pp. 387-393.
KANÍFOLUN EPOKSÍT3RKÍBLÍ ADDUKTLARININ PVX ÛÇÛN ÎÇIQ УЭ TERMOSTABÍLÍZATORLAR KÍMÍ ÍSTÍFADaSi
1M.S. Pirquliyeva, 2A.M. Quliyev
1Sumqayit Dôvlat Universiteti AZ 5008, Sumqayit §ah., 43 mahalla. E-mail: sdtk-1959@,mail.ru 2AMEA, Polimer Materiallari ínstitutu AZ 5004, Sumqayit §ah., S.Vurgun kûç., 124. E-mail: [email protected]
Kükürd tarkibli qlisidoksikarbonil va qlisidoksimetil avazli kanifoldan istifada etmakla plastifikasiya edilmiç PVXasasinda hazirlanmiç kompozitlarin temperatura va i§iga qar§i stabilliyi ôyranilmiçdir. Müayyan edilmiçdir ki, kanifol asasinda hazirlanmiç epoksid tarkibli adduktlar termiki davamlidirlar va onlar PVXkompozisiyalarin emal temperaturuna dózürlar. Gôstarilmiçdir ki, taklif olunan stabilizatorlar polimer matrisini i§iq selindan qorumaq xüsusiyyatina malikdirlar. Müayyan edilmiçdir ki, taklif olunan stabilizatorlardan istifada etmakla hazirlanmiç kompozisiya nümunalari yüksak temperatura, zarbaya va çaxtaya davamliliq va mexaniki môhkamlik xüsusiyyatlari ózünda aks etdirirlar.
Açar sôzlw. kanifol, polivinilxlopid, epoksid, stabilizator, temperatura davamliliq, mexaniki môhkamlik
ЭПОКСИСОДЕРЖАЩИЕ АДДУКТЫ КАНИФОЛИ В КАЧЕСТВЕ СВЕТО- И ТЕРМОСТАБИЛИЗАТОРОВ ДЛЯ ПВХ
1 2 М.С. Пиргулиева, А.М. Гулиев
1 Сумгаитский государственный университет AZ5008, г.Сумгайыт, 43 квартал. E-mail: sdtk-1959@,mail.ru
2Институт Полимерных Материалов НАН Азербайджана, AZ5004, г.Сумгайыт, ул С.Вургуна, 124. E-mail: [email protected]
ЕРОХУ-СОЭТАШШО АББиСТ8 ОЕ
463
Изучена термо- и светостабилизирующая активность глицидилоксикарбонил- и глицидилоксиметилзамещенных производных серосодержащей канифоли в композициях на основе пластифицированного поливинилхлорида. Показано, что предложенные эпоксипроизводные аддукты канифоли обладают термической устойчивостью, позволяющей им выдерживать температуру переработки поливинилхлоридных композиций. Разработки показали, что предложенные стабилизаторы способны защитить полимерную матрицу от светового излучения. Установлено, что изготовленные с участием предложенных стабилизаторов пленочные образцы проявляют высокую термическую устойчивость, ударопрочность, хорошую морозостойкость и механическую прочность. Ключевые слова: канифоль, поливинилхлорид, эпоксипроизводные, стабилизатор, термическая устойчивость, ударопрочность,
