Stability Of PVC Research Articles

Enhancing fire performance and thermal stability of flexible PVC with lanthanum phytate montmorillonite

This study presents a breakthrough approach to enhance the thermal stability, mechanical properties, and flame retardancy of flexible PVC (fPVC). It introduces lanthanide phytate montmorillonite (Pa-La-Mt) as an innovative nanofiller. Pa-La-Mt was synthesized by intercalating sodium phytate and lanthanum chloride into the interlayer space of montmorillonite (Mt), effectively increasing the layer spacing. The analysis of this study, using X-ray diffraction (XRD) and Fourier infrared spectrometer (FTIR), confirmed this structural transformation. The influence of Pa-La-Mt on the structural and performance aspects of fPVC composites was thoroughly examined. Scanning electron microscopy (SEM), thermogravimetric analysis (TGA), mechanical testing, limit oxygen index (LOI), and cone calorimeter (CONE) revealed compelling outcomes. Pa-La-Mt not only improved the dispersion and compatibility of Mt. within the fPVC matrix but also enhanced the thermal stability and mechanical performance of fPVC composites. Most notably, Pa-La-Mt exhibited remarkable flame retardant and smoke suppression effects on fPVC composites. It led to a substantial increase in LOI value, a reduction in the peak heat release rate and total heat release amount, and a decrease in CO and CO2 emissions. This underlines Pa-La-Mt as a promising nanofiller with profound implications for various fPVC applications.

A “one‐pot” method for synthesizing zinc tryptophan and its derivatives as highly efficient PVC thermal stabilizer with excellent mechanical properties

AbstractZinc Tryptophan (Trp‐Zn) and zinc N‐(salicylic) tryptophan (SalTrp‐Zn) were synthesized from tryptophan, zinc acetate, and salicylic aldehyde by one‐pot method, respectively. The structure was analyzed by FT‐IR, 1H NMR, and elemental analysis. PVC samples were prepared by stirring method and solvent film process, and then the thermal properties of PVC samples were studied by thermal aging chamber test, Congo red test, electrical conductivity test, and thermogravimetric analysis (TGA). The thermal stability of Trp‐Zn and SalTrp‐Zn stabilized PVC samples was better than calcium and zinc soaps used in industry. The thermal stability time was up to 80 min, and it was a long‐acting thermal stabilizer. After the addition of CaSt2 and Trp‐Zn stabilizer in different proportions, the thermal stability of PVC was obviously improved, and the initial whiteness of the film was improved after the combination of Trp‐Zn/SalTrp‐Zn. In addition, the tensile test verified that the PVC samples stabilized by Trp‐Zn and SalTrp‐Zn had the highest elongation at break. The addition of Trp‐Zn can reduce the elastic modulus of PVC, effectively improve the mechanical properties of PVC, and make the PVC film have better toughness and elasticity. Through DMA and EDS tests, it can be seen that Trp, SalTrp‐Zn had good compatibility with PVC and DOP. The quantum chemical calculation of Trp‐Zn, SalTrp‐Zn and vinyl chloride models was carried out, and the thermal stability mechanism of thermal stabilizer on PVC was analyzed accurately, mainly the absorption mechanism of HCl and the substitution mechanism of unstable chlorine atoms.

Mechanical and thermal properties of rigid PVC and graphene nanocomposites obtained by melt–mixing

The effect of graphene (0.01, 0.1, 0.5 and 1 wt%) on the mechanical properties and thermal stability of rigid PVC was investigated. The morphology and thermal properties were analyzed by scanning electron microscopy (SEM) and thermogravimetric thermal analysis (TGA). Additionally, tensile properties, impact strength and hardness were determined. It was found that the addition of graphene can increase the impact strength and hardness and extend the thermal stability time of PVC.

THERMAL DEGRADATION OF POLY(VINYL CHLORIDE)/POLYSTYRENE BLENDS IN THE PRESENCE OF DERIVATIVES OF Hura crepitans SEED OIl.

Poly(vinyl chloride) (PVC) is a versatile polymer that has found applications in various sphere of our daily life. However, it is intrinsically unstable at elevated temperatures usually employed in processing it into useful articles. The thermal stability of poly(vinyl chloride) (PVC) has been reported to improve in a blend with polystyrene (PS) and compatibility of the polymers was a factor which influenced the stabilization process. There has been no report of thermal stability of PVC/PS blends in the presence metal soap of seed oil. In this study, the thermal degradation of poly(vinyl chloride)/polystyrene (PVC/PS) blends in the absence and presence of metal soaps of Hura crepitans seed oil (HCSO) has been investigated in air and under nitrogen atmosphere. Metal soaps of Hura crepitans seed oil; Al, Ba, Ca, Mg and Zn were prepared by precipitation method involving metathesis in alcohol. Kinetics of thermal degradation of PVC and the blends were carried out titrimetrically in the temperature range 170-190 oC under nitrogen atmosphere. The interaction of the additives with PVC was studied with FTIR spectrophotometer while the melt properties of PVC and the blends were determined using differential scanning calorimeter. The thermal stability study of the polymer and the blends was carried with thermogravimetric analyzer under nitrogen and air atmospheres. In the absence of metal soaps, the kinetics of thermal degradation of PVC in PVC/PS blends, 95/5, and 90/10 ratios, measured titrimetrically under nitrogen atmosphere in the temperature range 170- 190 oC, was determined by the rates of dehydrochlorination of the polymer. The rates of dehydrochlorination were of the order, 10-2 %min-1 and showed stabilization of PVC by PS in the blends. Specifically, at 190 oC, the rates of dehydrochlorination of PVC under nitrogen atmosphere were reduced by 23.7 and 11.2% for the 95/5 and 90/10 blends respectively with calculated activation energy of 50.7kJ mol-1for the process. In the presence of HCSO soaps of Al, Ba, Ca, Mg and Zn, there were marked reductions in stabilization of PVC by PS and were associated with increased polarity of the blends. Miscibility of the blends was enhanced by the soaps, as was evident from FTIR and DSC analyses, showing from the latter, single Tgs of 98.2 and 96.2 oC for 95/5 and 90/10 blends respectively. The enhanced stability of PVC in the blends by PS and reduced stability of the polymer in the presence of metal soaps were confirmed by thermogravimetry. PS enhanced thermal stability of PVC in PVC/PS blends while the presence of metal soaps of Hura crepitans seed oil in PVC/PS blends is antithetical to thermal stability of PVC.

Anti-cancer Schiff bases as photostabilizer for poly(vinyl chloride)

To prevent or reduce the drawback effect and prolong the life of PVC and preserve its composition and efficiency, compounds are incorporated with PVC. In this work, three highly aromatic anti-cancer Schiff base compounds in symbol (C2, C3 and C5) were applied to photostabilize of PVC against photodegradation, by added it to the polymer in the form of Schiff bases, to increase the stability of polymer when irradiated with ultraviolet (UV) light, (λmax = 365 nm) at 30 ºC, with the intensity of the light wavelength at 1920 lux for a long duration. The PVC was blended with Schiff's base in concentration (0.5 %wt.), with thickness films (40 μm) were made from the blended materials. Several methods were used, including infrared spectroscopy, surface examination of irradiated films to know the effect of additives on PVC photostabilization and conductivity of films were measured by LCR meter. The results showed that the additives significantly reduced the photodegradation of PVC. C2 compound as additive, stabilize PVC more than other additives, it can absorb harmful radiation, deactivate hydrogen chloride, and scavenge high-energy species such as peroxides. Several mechanisms of photostabilization for C2 compound have been suggested. Therefore it is acting as stabilizers for PVC.
 KEY WORDS: PVC, Photostabilizer, UV radiation, AFM, FESEM, LCR-meter
 Bull. Chem. Soc. Ethiop. 2024, 38(1), 135-146. DOI: https://dx.doi.org/10.4314/bcse.v38i1.11

Study on the Thermal Stabilizing Process of Layered Double Hydroxides in PVC Resin

Poly(vinyl chloride) (PVC) is widely used in various fields and requires the use of thermal stabilizers to enhance its thermal stability during processing because of its poor thermal stability. Layered double hydroxides (LDHs) are widely considered to be one kind of highly efficient and environmentally friendly PVC thermal stabilizer. To investigate the thermal stabilizing process of layered double hydroxides (LDHs) in PVC resin, PVC and MgAl-LDHs powders with different interlayer anions (CO32−, Cl−, and NO3−) were physically mixed and aged at 180 °C. The structure of LDHs at different aging times was studied using XRD, SEM, and FT-IR. The results show that the thermal stabilizing process of LDHs on PVC mainly has three stages. In the first stage, the layers of LDHs undergo a reaction with HCl, which is released during the thermal decomposition of PVC. Subsequently, the ion exchange process occurs between Cl− and interlayer CO32−, resulting in the formation of MgAl-Cl-LDHs. Finally, the layers of MgAl-Cl-LDHs react with HCl slowly. During the thermal stabilizing process of MgAl-Cl-LDHs, the peak intensity of XRD reduces slightly, and no new XRD peak emerges. It indicates that only the first step happens for MgAl-Cl-LDHs. The TG-DTA analysis of LDHs indicates that the interaction of LDHs with different interlayer anions has the following order: NO3− < CO32− < Cl−, according to the early coloring in the thermal aging test of PVC composites. The results of the thermal aging tests suggest that LDHs with a weak interaction between interlayer anions and layers can enhance the early stability of PVC significantly. Furthermore, the thermal aging test demonstrates that LDHs with high HCl absorption capacities exhibit superior long-term stabilizing effects on PVC resin. This finding provides a valuable hint for designing an LDHs/PVC resin with a novel structure and excellent thermal stability.

Microplastics and additives in patients with preterm birth: The first evidence of their presence in both human amniotic fluid and placenta

Considering the well documented, almost ubiquitous nature of microplastics in different environments, the exposure of pregnant women to microplastics may pose risks to the unborn children. The study focused on investigating the presence of microplastics in amniotic fluid and placenta, and brings the first evidence of the simultaneous presence of microplastics and additives in both human amniotic fluid and placentas. In total, 20 samples of amniotic fluid and placenta from 10 patients were analyzed for the presence of microplastics and plastic additives by Fourier transform infrared spectroscopy – attenuated total reflectance (FTIR–ATR) after alkaline digestion with KOH. In 9 out of 10 patients, microplastics or additives were found in amniotic fluid, placenta, or both. Specifically, 44 particles of microplastics and polymer additives were identified in all samples. Chlorinated Polyethylene (CPE) and Calcium zinc PVC Stabilizer with particle sizes between 10 and 50 μm prevailed. Although all women involved in this study, who provided placenta and amniotic fluid samples, experienced physiological, singleton pregnancies complicated with preterm prelabour rupture of membranes (PPROM), it is too early to draw any conclusions and more research is needed.

Study on Application and Mechanism of Alkali Sulfadiazine Neodymium as PVC Heat Stabilizer

In this paper, the alkali sulfadiazine neodymium (NdSD) was prepared from sulfadiazine and neodymium nitrate hexahydrate under alkaline conditions, and used as a heat stabilizer on PVC. The structure of NdSD was characterized by elemental analysis and infrared spectrum. The results show that the molecular formula of NdSD is Nd (SD)2·OH·H2O. The thermal degradation process of NdSD at 25-800°C was characterized by thermogravimetric analysis. The results show that the decomposition temperature of NdSD is higher than 200°C, which is suitable for PVC thermal stabilizer. The thermal stabilizer time of PVC by NdSD was characterized by static Congo red method. The results showed that the thermal stabilizer time of PVC increased from 2.7min to 23.2 min after adding NdSD. The discoloration effect of NdSD on PVC was characterized by oven discoloration method. The results indicate that PVC samples added with NdSD show better effect than other heat stabilizers. By means of silver nitrate solution method and Fourier transform infrared spectroscopy, it was proved that sulfadiazine neodymium can absorb and react with HCl, and further proposed a possible mechanism of NdSD stabilization of PVC.

Metal Oxide Nanoparticles Containing Clotrimazole to Suppress Photodegradation of Poly(Vinyl Chloride) Thin Films.

Pol(vinyl chloride) or PVC has functional properties that enable its use in many industrial applications. It suffers from aging, however, in harsh conditions (e.g., elevated temperature or high humidity levels) if oxygen is present. One way to enhance the photostability of PVC is to blend it with additives. Thus, thin films were made by mixing PVC with clotrimazole, and five metal oxide (titanium, copper, cobalt, chromium, and nickel oxides) additives. The metal oxides and clotrimazole were added at concentrations of 0.1 and 0.5% by weight, respectively. The effect of the metal oxide nanoparticles accompanied by clotrimazole on the photodegradation of PVC was then assessed. The results indicated that the additives have a stabilizing effect and protect PVC against photodegradation significantly. The formation of polymeric fragments of small molecular weight containing carbon-carbon double bonds and carbonyl groups was lower in the blends containing metal oxide nanoparticles and clotrimazole than in unblended PVC. Similarly, the decrease in weight was much less for the films blended with additives. Additionally, surface analysis of the irradiated polymeric films showed significantly lower damage in the materials containing additives. The most effective additive in the stabilization of PVC was nickel oxide nanoparticles. The metal oxides are highly alkaline and act as scavengers for the hydrogen chloride produced during the photodegradation of PVC. They additionally act as peroxide decomposers. In contrast, clotrimazole can absorb harmful radiation and act as an ultraviolet absorber due to its heteroatom and aromatic content. Thus, the use of a combination of metal oxide nanoparticles and clotrimazole led to significant improvement in the resistance of PVC toward photodegradation.

Synthesis of zinc Schiff base complex and its application as highly efficient thermal stabilizer for flexible poly (vinyl chloride)

N, N'-bis (salicylaldehyde) ethyldiamino-zinc (BSE-Zn) was synthesized from salicylaldehyde and ethylenediamine. Its structure was analyzed by FT-IR, 1H NMR and elemental analysis. The thermal properties of PVC samples were studied by thermal aging oven test, Congo red test, conductivity test, thermogravimetric analysis (TGA) and UV–Visible spectroscopy (UV–Vis). The thermal stability of BSE-Zn stabilized PVC samples was better than the calcium zinc soaps used in industry. The thermal stability time can be as long as 90 min, which proved that BSE-Zn was a long-term thermal stabilizer. By blending CaSt2 and BSE-Zn stabilizer in different proportions, the thermal stability of PVC was significantly improved while improving the initial color. When the compound ratio is CaSt2/BSE-Zn=2:1, the thermal stability of PVC sample was best and didn't age until 120 min. In addition, it was verified by tensile test that the PVC sample stabilized by BSE-Zn had the highest tensile strength and elongation at break, which could improve the mechanical properties of PVC and make the PVC film have better toughness and elasticity. the quantum chemical calculation of BSE-Zn and vinyl chloride models was carried out, and the thermal stability mechanism of BSE-Zn on PVC was analyzed accurately, mainly the absorption mechanism of HCl and the replacement mechanism of unstable chlorine atoms.

Intercalated rare earth hydrotalcite‐like materials and their application in stabilizers in poly (vinyl chloride)

AbstractIn this research, ZnAlLa‐itaconate‐LDHs was synthesized by means of Co‐precipitation‐hydrothermal method. The effects of aluminum‐lanthanum ratio, co‐precipitation time, hydrothermal time, and hydrothermal temperature on the crystal structure were studied. As a result, the optimum condition was found to be: n(Al3+): n(La3+) = 10:1, co‐precipitation time 24 h, hydrothermal time 8 h, and hydrothermal temperature 180°C. The influence of ZnAlLa‐itaconate‐LDHs on the thermal stability properties and plasticizing properties of PVC were investigated, exhibiting long‐term stability of 76 min with short plasticizing time of 1.11 min. Long‐term thermal stability mechanism was studied by FTIR before and after hydrochloric acid treatment. It was demonstrated that the thermal stabilizer ZnAlLa‐itaconate‐LDHs prevented the rupture of the CCl bond in PVC and inhibited the development of HCl. Consequently, impeded the production of CC bond and playing a role in thermal stabilization of PVC.

Morphology and Performance of PolyVinyl Chloride Thin Films Doped with Polyorganosilanes against Photodegradation

The importance of polymeric additives has taken an important role in industrial technology and its development and the increase in the consumption period of industrial products, especially plastic products. Therefore, a different type of polymeric additive was used, which can be classified as another type of polymeric additive, where three types of polymers were synthesized as polymeric additives. These polymers differ from each other only in stereo geometry. Three geometric shapes of the polymer were synthesized, namely, ortho, meta, and para polymers. They were studied as photo stabilizers for PVC and compared as the best photostabilizer for PVC. Polyorganosiloxane was invented by various technologies. Polyorganosilanes and poly(vinyl chloride) (PVC) were combined to create homogeneous films. Various methods were used to investigate the effects of long-term irradiation on polyorganosilane-containing films. The development of side products containing polyene and carbonyl groups was observed in the infrared spectra of PVC films before, during, and after irradiation. The absorption bands' intensities of the functional groups associated with the polyorganosilanes were lower when it was present. Furthermore, it was observed that the weight of PVC films dropped less when irradiating them after hybridization with polyorganosilanes. In the presence of polyorganosilanes, there was also a minor alteration in the surface of irradiated PVC. Photodegradation of PVC is inhibited by polyorganosilanes. Hence, the role of polyorganosilanes to stabilize PVC against UV exposure has been studied.

Enhancement of Photostabilization of Poly(Vinyl Chloride) in the Presence of Tin-Cephalexin Complexes.

Poly(vinyl chloride), PVC, has many attractive properties, including low cost of manufacture, resistance to acid and alkali corrosion, and ease of molding. However, PVC suffers from aging in harsh conditions, leading to the shortening of its useful life. Stability to irradiation, for example, can be improved through the incorporation of additives to PVC. The design, synthesis, and application of new stabilizers continue to attract attention. The current work investigates the effect of three tin-cephalexin complexes on the stability of PVC on irradiation with ultraviolet (UV) light (λ = 313 nm) at 25 °C for a long duration. The PVC was blended with tin-cephalexin complexes at low concentrations (0.5% by weight), and thin films (around 40 µm) were made from the mixed materials. Various methods, including weight loss, infrared spectroscopy, and surface inspection of irradiated films were used to investigate the role played by these additives in the inhibition of PVC photodecomposition. The results confirmed that the additives led to a significant reduction in the rate of photodecomposition of the PVC blends. Tin-cephalexin complexes can absorb harmful radiation, deactivate hydrogen chloride, and scavenge high-energy species such as peroxides, therefore acting as stabilizers for PVC.

The Promoting Effect of Multifunctional Groups on the Thermal and Mechanical Properties of PVC Materials

The development of PVC materials grafted with mannich base originated from myrcene (P-MAM-g, where the mannich base derived from myrcene is abbreviated as MAM) via green and effective synthetic methods is a good strategy to avoid unacceptable discoloration and deterioration of thermal and mechanical properties caused by autocatalytic dehydrochlorination (DHC) during PVC processing. In this study, MAM with double bonds, amino groups, ester groups, and phospholipid groups was introduced into the chains of PVC to improve the thermal stability of PVC. The experimental results showed that the covalent attachment of MAM to PVC enhanced both the initial and the long-term stability of PVC. The enhanced performance of P-MAM-g compared with unmodified PVC is attributed to the simultaneous introduction of double bonds and amino groups into the PVC structure. The double bonds trapped the unstable chlorine atoms originated from the degradation of the PVC chain and reacted with the labile macromolecular radicals originated from PVC, thus inhibiting the radical degradation of the PVC chain. Furthermore, the amino groups absorbed the HCl produced in the degradation of PVC, inhibiting the adverse effects of HCl. P-MAM-g displayed better intrinsic flexibility and anti-migration ability of organic functional components compared with the control PVC materials. A possible stabilizing mechanism of the P-MAM-g was also presented.

Improving the Long-Term Performance of Poly(Vinyl Chloride)

Since neat PVC is rigid, in all applications a plasticizer is added. Migration of the plasticizer results in brittleness of flexible PVC and environmental pollution. We have used three types of cross-linking agent blended with commercial PVC, plasticizer and thermal stabilizer. Heat treatments at 100С, 121С and 136C were performed. We made tensile tests, dynamic friction tests, wear rate determination, scratch resistance determination, water absorption tests and SEM analysis – to make selection of compositions suitable for sufficient cross-linking for long term applications.

Synthesis of a bio‐based plasticizer from vanillic acid and its effects on poly(vinyl chloride)

AbstractA new bio‐based plasticizer, VA8‐8, was prepared derived from vanillic acid, and its structure was verified by nuclear magnetic resonance. It was incorporated into poly(vinyl chloride) (PVC) to replace dioctyl phthalate (DOP), and its plasticizing performance was evaluated. The results indicated that VA8‐8 shows good compatible with PVC resin, and has a excellent plasticizing effect for PVC. When DOP was partially or completely substituted with VA8‐8, the Tg value PVC blends dropped from 34.6 to 24.3°C and the elongation at break increased from 196.4% to 301.9%, suggesting the enhanced plasticizing efficiency of plasticizer. The plasticizing mechanism was also simulated, and the interactions between VA8‐8 and PVC molecules were discussed. The thermogravimetric analysis showed VA8‐8 can more effectively improve the thermal stability of PVC than DOP. In addition, the migration resistance of VA8‐8 was generally superior to that of DOP. Therefore, VA8‐8 is a comparable to or better plasticizer than DOP, and it is a promising alternative plasticizer for PVC.

Synergistic Effect of Two Plasticizers on Thermal Stability, Transparency, and Migration Resistance of Zinc Arginine Stabilized PVC.

The effect of different plasticizers on thermal stability, transparency, and migration resistance of the PVC stabilized with zinc arginine [Zn(Arg)2] was investigated. The thermal stability, migration resistance, and transparency of PVC with tributyl citrate (TBC) were better than PVC with dioctyl phthalate (DOP) characterized by oven aging method, migration test, and near infrared-visible-ultraviolet spectrophotometer. At the same time, the longer the carbon chain in citric acid esters, the better the thermal stability and transparency of PVC sample. The hydroxyl group in citric acid esters is helpful to improve the thermal stability of PVC samples. However, the elongation at break and Tg value of PVC containing DOP were very close to those of PVC containing TBC. The calculation results of Hansen solubility parameters also illustrated that DOP had better compatibility with PVC than TBC. Therefore, the excellent transparency and thermal stability of TBC plasticized PVC were attributed to the good compatibility between TBC and Zn(Arg)2, which was verified by the solubility test. Lastly, the mixture of dioctyl terephthalate (DOTP) and TBC was used as plasticizers for Zn(Arg)2 stabilized PVC. When the ratio of TBC and DOTP was 1:1, the transparency, thermal stability, and migration resistance of Zn(Arg)2 stabilized PVC samples were better than those of PVC plasticized by DOP or TBC alone. The mechanism was that the compatibility between Zn(Arg)2 and PVC was greatly improved by the synergetic effect of TBC and DOTP, resulting in the improvement of thermal stability, migration resistance, and transparency of PVC samples.

Chemical, thermal and mechanical evaluation of poly(vinyl chloride) plastisol with different plasticizers

The most widely used plasticized polymer is poly(vinyl chloride) (PVC) due to its excellent plasticizer compatibility characteristics. Traditionally, PVC plasticizers belong to the phthalate family; however, they have harmful effects on human health and the environment. In this work, we evaluated the effect of six types of plasticizers (dioctyl phthalate, dioctyl adipate, Lestarflex (a polymeric polyester plasticizer), polycaprolactone, polyester polyol, and 1,2,3-propanetriol triacetate) on the properties of PVC plastisol used in manufacturing shoes and toys. The mechanical properties (hardness, tensile strength, tear strength, and elongation at break) were evaluated before and after accelerated aging tests (in an ultraviolet oven and at 50°C). A thermal study was also carried out using differential scanning calorimetry and thermogravimetric analysis, while possible structural changes during deformation were investigated using the small-angle X-ray scattering technique. In general, the results have shown that in the plasticization and stabilization of PVC, the plasticizer dioctyl phthalate can be replaced by dioctyl adipate or Lestarflex without relevant changes in the final properties of the material, even after accelerated aging.

Rare earth Ce based metal organic framework as efficient synergistic thermal stabilizer for PVC: Preparation and thermal stabilization behavior

The complex production process and uneven performance seriously restrict the application of Rare earth thermal stabilizer. In this study, the thermal stability behavior of metal organic framework Ce(1,3,5-BTC)(H2O)6 (Ce-BTC) towards PVC was studied. Experimental results showed that the combination of Ce-BTC, 2,4,6-tris[di(hydroxymethyl) amino]-1,3,5-triazine (HHTT), and ESBO synergistically stabilized PVC sample displayed significantly improved initial color, meanwhile, the Ts and the time of "zinc burning" were prolonged to 55.17 and 70 min, respectively, as well. During thermal treatment, HHTT can replace the unstable chlorine atoms on the PVC chain, and the incompletely coordinated Ce ions in Ce-BTC can inhibit the further polymerization of conjugated polyenes by reacting with the alkene chain resulted from PVC degradation, these two factors synertistically inhibit the degradation of PVC. The nertralization of HCl by HHTT and ESBO can provide longer reaction time for incompletely coordinated Ce ions and chlorine atoms, delaying the autocatalytic effect of HCl.

Study of an unknown PVC cable formulation by mechanical properties

PVC is a type of thermoplastic material which affected by heat due to the presence of chlorine and which is not used alone but with addition of additives such as stabilizers, plasticizers, fillers and others according to the required properties of the desired product based in suitable formulations. In this work many experiments were carried out to evaluate the additives and the type of PVC used on the formulation in cables application. The first experiments were to vary the amount of filler (calcium carbonate) and that ingredients such as PVC K67 resin, lubricant (stearic acid), stabilizer (tri-base lead sulfate), and plasticizer (Dioctyl phthalate) were constant in the formulation and then samples were tested for density, hardness, tensile strength, and sample burn test to determine the content of fillers or plasticizers. The results of the density test showed that it was 23.91wt% of the filler and in the hardness test, the plasticizers used were estimated at 52.61wt%. The tensile test results were 10.6 wt% of filler when the plasticizer value was 60wt% or 20wt% of filler with 65wt% of plasticizer weight. And it turned out that the unknown sample used PVC and high molecular weight such as pvck70-72 and not Pvck67 which we used in all experiments and the result of burning the sample gave 21.9% of the ash which is a filler. In the second experiments, the stabilizer was changed and the rest of the components were considered fixed, and the result was that the weight of the stabilizer was less than the lowest value used in the experiments 6wt% and finally. The study concluded that the sample used high molecular weight PVC, the filler percentage was 20wt%-23.9wt%, and the plasticizer was 52.61wt%-65.7wt%. This study shows that the proportions of the components of the PVC formulation can be estimated by studying the effect of fillers and heat stabilizers by using mechanical tests.