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اسم الطالبة :
رغد محمد عمر

"Synthesis of some Gallic acid derivatives an study their using as photostabilizer for (PVC) films"
ragad1Gallic Acid compounds and Its Derivatives compounds:
Gallic acid (trihydroxybenzoic acid) , is a type of organic and phenolic acid also known as 3,4,5-trihydroxybenzoic acid or a poly hydroxyl phenolic compound .

structure of Gallic Acid(C7H6O5)
It is found in a variety of fruits and vegetables , such as gallnut , grape , sumac , oak bark , green tea , apple peels , strawberries , pine apples , bananas and lemons.
Heterocyclic compounds :
Heterocyclic compounds may be inorganic , which contain within the ring structure at least one atom of carbon , and one or more elements “Synthesis of some Gallic acid derivatives an study their using as photostabilizer for (PVC) films”such as sulfur , oxygen , or nitrogen
Thiadiazole :
Thiadiazole is a5-membered ring system containing hydrogen-binding domain, sulphur atom, and two-electron donor nitrogen system (–N=C–S) which exhibit a wide variety of biological activity.
• plastics :
Most plastics contain organic polymers. The vast majority of these polymers are based on chains of carbon atoms alone or with oxygen, sulfur, or nitrogen as well.
Changes in polymer properties due to chemical, physical or biological reactions resulting in bond scissions and subsequent chemical transformations are categorized as polymer degradation. Degradation reflects changes in material properties such as mechanical, optical or “Synthesis of some Gallic acid derivatives an study their using as photostabilizer for (PVC) films”electrical characteristics in crazing, cracking, erosion, discoloration and phase separation.
Why choose Poly)vinyl chloride(?
The low cost and the good performance of poly vinyl chloride products have increased the utilization of this polymer in building, mainly in exterior application, such as window profiles, cladding structure and siding.
However, ultimate user acceptance of the PVC products for outdoor building applications will depend on their ability to resist photodegradation over long periods of sunlight exposure. To ensure weatherability, the PVC resin needs to be compounded and processed properly, using suitable additives, leading to a complex material whose behavior and properties are quite different from the PVC resin by itself

Comp. No. X mp°C Yield % Molecular formula
1 -OCH3 200 – 203 92 C18H20N2O6
2 -CH3 187 – 189 93 C18H20N2O5
3 -Cl 198 – 200 88 C17H17N2O5Cl
4 -H 184 – 187 85 C17H18N2O5

The FTIR spectra of PVC films :
Fig.(1)FTIR spectrum of the PVC+(R1)
Fig.(2) FTIR spectrum of the PVC+(R4)

Fig.(3)Variation of natural logarithm of (At–A∞) with irradiation time of PVC (control) film (40μm)

Fig .(4) Variation of natural logarithm of (At–A∞) with irradiation
time of PVC+R1 film(40μm)

Table (2) Photodecomposition rate constants (kd) of PVC films thickness (40μm) containing 0.5 % of additives
Polymers kd (S-1)
PVC (control) 8*104-
PVC+ R4 5*104-
PVC+ R3 4*104-
PVC+ R2 2*104-
PVC+ R1 1*104-

Band index method which includes:

As = Absorbance of peak under study.
Ar = Absorbance of reference peak.
Is = Index of the group under study.

Fig.(5) The relationship between the carbonyl index and irradiation time for PVC films (40µm thickness) containing different additives. Concentration of additives is fixed at 0.5% by weight

Fig.(6) The relationship between the hydroxyl index and irradiation time for PVC films (40µm thickness) containing different additives. Concentration of additives is fixed at 0.5% by weight

Fig.(7) The relationship between the polyene index and irradiation time for PVC films (40µm thickness) containing different additives. Concentration of additives is fixed at 0.5% by weight.
Weight loss % :
The stabilizing efficiency was determined by measuring the weight loss% of photodegraded PVC films with and without additives by applying the following equation:
Weight loss % = [ (W1 -W2 ) / W1 ] 100

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