Stability Of Polyvinyl Chloride Research Articles

Using solid waste from the leather tanning industry to produce a mixed calcium/zinc thermal stabilizer for polyvinyl chloride

The leather tanning industry has historically posed considerable environmental challenges owing to the substantial solid waste it produces. This study examines innovative uses for the solid waste generated by this sector, focusing on the waste from the fleshing process. Our research involved extracting fat from fleshing waste, synthesizing Ca and Zn carboxylates from the extracted fat, and assessing their effectiveness as a combined Ca/Zn thermal stabilizer for polyvinyl chloride (PVC). The synthesized Ca and Zn carboxylates contained 6.4% Ca and 11.4% Zn, respectively, while the total fatty matter was determined to be 86.2% and 88.5%, respectively. Thermal analysis indicated that both carboxylates remained stable up to 200 °C. Tests on dehydrochlorination and roll milling revealed that the mixed Ca/Zn thermal stabilizer effectively improved the thermal stability of PVC resin. It also showed a synergistic effect when combined with pentaerythritol, enhancing its overall efficacy. The synthesized mixed Ca/Zn thermal stabilizer exhibited thermal stabilizing properties and flowability comparable to those of mixed Ca/Zn stearate, a widely used thermal stabilizer for PVC. These results suggest that fleshing fat could serve as a valuable raw material in the production of mixed Ca/Zn-based PVC thermal stabilizers.

Organometallic complexes and reaction methods for synthesis: a review

Abstract Organometallics are chemical compounds that consist of carbon-metal linkages. They have emerged as a result of the combination of organic and inorganic chemistry and exhibit a stable metal-carbon bond in solution. These compounds possess properties that lie between those of ionic and covalent bonds, making them highly significant in various industries. The fact that organometallics are present in all living organisms further emphasises their importance. In this overview, we will explore general reactions, such as substitution and insertion reactions, as well as different techniques for creating organometallic complexes. Additionally, we will provide a brief synthesis review of various types of organometallic complexes, including carbonyls, hydrides, alkyls, carbenes, and carbines. Organometallic compounds find extensive applications in stoichiometric chemical processes in both research and industry. Moreover, they serve as catalysts to enhance these reactions, making them more than just theoretical compounds. For example, organotin compounds are widely used as fire retardants, polymers, medications, insecticides, and stabilizers for polyvinyl chloride.

A comparative study of comprehensive performances for transparent plasticized polyvinyl chloride films with different plasticizers

AbstractFor flexible polyvinyl chloride (PVC) films with excellent mechanical performances and high transparency, the demand for antistatic properties is becoming increasingly urgent in textile and electronic fields. This study compares the effects of 60 phr bis (2‐(2‐butoxyethoxy) ethyl) adipate (DBEEA) with other five equal amounts of plasticizers on the conductivity, electrical stability, transparency, and mechanical properties of plasticized PVC. The infrared spectra of plasticizers indicate that there are unique ether groups exist in DBEEA. Then the calculated solubility parameters suggest the good compatibility between DBEEA and PVC. For conductivity, the volume resistivity and surface resistivity of the PVC sample with DBEEA (PVC/DBEEA) are 107 Ω· m and 1010 Ω, respectively, which are both lower by 3–4 orders of magnitude than that of other plasticized PVC. For electrical stability, the results indicate that PVC/DBEEA placed in air still maintains lowest resistivities. Under 10, 23, and 30°C, PVC/DBEEA keeps high and stable electrical properties. The similar refractive indices of DBEEA and PVC resin prepared by suspension method indicate good transparency for PVC/DBEEA. Moreover, PVC/DBEEA still has good mechanical property.

Valorization of palm oil refining by-product for organotin mercaptide as a polyvinyl chloride thermal stabilizer: Synthesis, efficacy and comparison to mixed metal stearate

Organotin mercaptide-based thermal stabilizer is recognized for its effectiveness in enhancing thermal stability of polyvinyl chloride (PVC). In this study, we synthesized an organotin mercaptide-based thermal stabilizer from palm fatty acid distillate, which is a by-product of palm oil refining process, and then evaluated its thermal stabilizing effects on PVC and compared its efficacy and economics to those of mixed metal stearate. The synthesized thermal stabilizer manifests as methyltin mercaptoethyl carboxylate sulfides. Both dehydrochlorination and two-roll mill discoloration tests have demonstrated the high efficacy of the resulting thermal stabilizer in stabilizing PVC, surpassing the performance of mixed metal stearate, as evidenced by the lower dosage required. The synthesized PVC thermal stabilizer not only provides effective stabilization but also presents a competitive viable alternative.

Amorphization Activates Biocompatible MgAl‐Layered Double Hydroxide for Efficient Multiple Free Radical Scavenging

AbstractThe exploitation of effective and nontoxic materials with antioxidant activity to mitigate or inhibit the damage caused by elevated levels of free radicals has attracted considerable attention across diverse fields. Herein, this study demonstrates that a biocompatible MgAl‐layered double hydroxide (LDH) can be activated for multiple types of free radical scavenging with unexpected activity through amorphization (a‐MgAl‐LDH). Detailed characterization reveals that numerous oxygen defects are introduced after amorphization. Mechanistic studies and theoretical simulations indicate that amorphization‐induced oxygen defects in a‐MgAl‐LDH promote radical adsorption and reduce the reaction energy barriers, thereby resulting in enhanced radical scavenging activities. Consequently, a‐MgAl‐LDH demonstrated remarkable efficiency in mitigating the oxidative injury induced by Rosup in cells and provided thermal stabilization of polyvinyl chloride against degradation. This study demonstrates the transformation of inert MgAl‐LDH into a promising, nontoxic, and cost‐effective nano‐antioxidant option for antioxidative therapy or polymer stabilization and highlights the significance of crystallinity engineering of nanomaterials for efficient free radical scavenging.

Utilizing a blend of expandable graphite and calcium/zinc stearate as a heat stabilizer environmentally friendly for polyvinyl chloride

AbstractPolyvinyl chloride (PVC) is one of the most important commercial plastics but it is thermally unstable at processing temperatures. Therefore, heat stabilizers are widely used to safeguard by improving resistance of PVC products at high temperature. But most of them are a highly toxic that can cause severe health issues in humans and harmful to the environment. In the present study mixed of calcium/zinc stearate heat stabilizer and green Expandable graphite (EG) is prepared via hydrothermal treatment using additives of nontoxic, environmental protection. The characteristics of the thermal stability of poly vinyl chloride can be investigated by Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) will be used to examine structure of the heat stabilizers, A universal testing equipment will be used to determine the mechanical properties and thermal gravimetric analysis (TGA). From TGA results the weight loss was 43.49% at 342°C for sample with Ca/Zn‐ stearate, while wt loss is 55.87% at 260°C for sample with EG which increase thermal stability. Differential scanning calorimetry affirmed the enhancement of PVC's thermal stability, showing a shift in the glass transition temperature an increase of 67°C. Mechanical tests indicated that samples with EG exhibited higher tensile strength and elongation at break, emphasizing the positive impact on PVC's mechanical properties. The burning test highlighted thermal stability of EG‐containing samples, retaining color and structure even after exposure to 180°C heat. This innovative approach not only enhances thermal stability but also aligns with eco‐friendly principles, making it a promising solution for improving PVC properties.Highlights Ca/Zn‐ stearate, expandable graphite developed by a safe hydrothermal process. Comprehensive analysis indicates improved thermal stability. Safe stabilization of eco‐friendly calcium/zinc, expandable graphite. Effective solution: Eco‐friendly, improved PVC properties. Expandable graphite improved mechanical properties of PVC.

Enhanced flame retardancy and thermal stability of zinc borate and magnesium carbonate as a promising alternative for Sb2O3 toward polyvinyl chloride

AbstractInorganic zinc compounds such as zinc carbonate (ZC) and zinc borate (ZB) are considered as promising alternatives for harmful antimony trioxide in the future, but may result in poor thermal stability for flexible polyvinyl chloride (PVC). To enhance the flame retardancy and static thermal stability of flexible PVC, zinc compounds with environmentally friendly magnesium carbonate (MC) were introduced into PVC matrix. Findings reveal that the simultaneous use of 5 phr ZB and 5 phr MC for flexible PVC exhibits satisfactory properties containing pronounced flame retardancy with a limiting oxygen index of 30.2% and a UL‐94 V‐0 rating without dripping, enhanced static thermal stability with high color stability by discoloration tests, reduced smoke emission, and decent mechanical properties, which are advantageous over the standalone use of ZC, ZB, and MC. The enhancement mainly due to that the incorporation of ZB can accelerate the dehydrochlorination and promote the charring of flexible PVC in the early stage of flame burning, and MC can perform the long‐term static thermal stability due to the HCl absorption capacity.

Solid phase synthesis of alkoxyl tin and the role of alkyl for Multi-stage thermal decomposition of polyvinyl chloride

To prepare an innovative thermal stabilizer for polyvinyl chloride (PVC), the micro-nano powders of alkoxyl tin (RxOSn) were synthesized via a solid phase reaction at room temperature, using the surfactant sodium benzene sulfonate (SBS) as a catalyst. Theoretical calculation of deprotonation reaction energy of monobasic alcohol and tin chloride was performed with the framework of DFT, and their structures were characterized by XRD, SEM, FT-IR, XPS, and its surface wetting performance was carried out by contact angle (CA). Meanwhile, the multi-stage thermal stability of PVC with 10% RxOSn sample, and the role of alkyl groups (Rx, x = 2 ∼ 5) in the RxOSn/PVC were investigated. The results show that the RxOSn samples exhibit a microstructure akin to the rutile of SnO2. Multi-stage kinetic studies of exothermic reactions has confirmed that the alkoxyl wetting performance of stabilizers becomes a determining factor, while the variation in activation energy (Ea) values seems to be mainly influenced by the Rx alkyl groups in the RxOSn samples. Besides, the differences in the lattice parameter a of RxOSn were validated to have a certain impact on the stabilizing effect of PVC, and the Ea of PVC degradation is closely related to the relative value of exposed crystal surfaces (D(110)/D(101)). This series of materials is easily synthesized and can effectively enhance the thermal stability of PVC, offering a wide range of potential applications.

Investigation of thermal and mechanical properties of new nitrogen-rich organic based heat stabilizers for poly (vinyl chloride)

Urea cyanurate, as a new nitrogen-rich organic-based heat stabilizer, for the enhancement to thermal properties of polyvinyl chloride (PVC) is prepared via the simple precipitation method, in this study. Characterization, thermal and mechanical properties of the stabilized PVC were examined by means of fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA/DTG), X-ray photoelectron spectroscopy (XPS) measurements, discoloration test, congo red test and the weight-loss method, thermal aging test, and tensile analysis. Results showed that the thermal stability of PVC is improved after the addition of urea cyanurate in PVC formulation and weight loss related to HCl releasing in the normal PVC processing temperature (180°C) is less than 1%. Enhancement of the thermal properties and stability time of the PVC lead to decreased degradation tendency. Oven-aging test result showed that the color change during degradation process of PVC samples improved by adding the urea cyanurate. The tensile strength of stabilized samples were about 42%, higher as compared to the pure PVC. The optimum and best results for improving the thermal and mechanical properties of PVC were obtained by incorporating the 3 wt % of the urea cyanurate.

Preparing epoxidized vegetable oil from waste generated by the kapok fiber industry and assessing its thermal stabilization effect as a co-stabilizer for polyvinyl chloride

This paper describes the epoxidation of vegetable oil derived from waste kapok seeds using performic acid, which was generated in situ with sulfuric acid acting as a catalyst. The mole ratio of formic acid to double bonds varied between 0.25 and 1.00. The completion of the reaction has been verified by analyzing FTIR and NMR spectra. The resulting epoxidized kapok seed oil (EKSO) has a maximum oxirane oxygen content of 2.7%, achieved at a formic acid to double bond mole ratio of 0.5. The study has also examined the potential use of EKSO as a co-stabilizer in the presence of Ca/Zn stearate for stabilizing polyvinyl chloride (PVC). Both static and dynamic tests demonstrated that incorporating EKSO into the Ca/Zn stearate system leads to a significant increase in the thermal stability of PVC. Moreover, the effectiveness of EKSO as a co-stabilizer was found to be comparable to that of epoxidized soybean oil (ESBO). However, the use of EKSO did result in a decrease in the strength of PVC due to an increase in plasticity, although this effect was minimal at low dosages and was also observed with ESBO. On the other hand, when utilizing small doses (<2 phr), there is a tendency for flowability to decrease, but the reduction is not significant either. Overall, these findings suggest that EKSO could be a valuable co-stabilizer for PVC in industrial applications, as it enhances PVC's thermal stability without significantly compromising its mechanical and flow properties.

Effect of different tin neodecanoate and calcium–zinc heat stabilizers on the thermal stability of PVC

Abstract Heat stabilizers are crucial additives for enhancing the thermal stability of polyvinyl chloride (PVC) during processing. Among the various heat stabilizers available, organic tin compounds have shown remarkable effectiveness. In this study, we investigated the use of dimethyltin dineodecanoate (DMTDN), dibutyltin dineodecanoate (DBTDN), and dioctyltin dineodecanoate (DOTDN) as heat stabilizers for PVC. These compounds were combined with calcium stearate (CaSt2) and zinc stearate (ZnSt2) to improve the thermal stability of PVC materials. The results demonstrated that the thermal stabilization effects of the three tin neodecanoates, when used as standalone heat stabilizers, followed the order: DOTDN &gt; DBTDN &gt; DMTDN. Notably, the thermal stability and lubricity of the three-component heat stabilizer (MTN5-C4Z1, BTN5-C4Z1, and OTN5-C4Z1, respectively), which consisted of the three types of tin neodecanoate, CaSt2, and ZnSt2 in a ratio of 5:4:1, outperformed the use of tin neodecanoate alone. This study offered potential formulations to reduce the application cost of tin neodecanoate as a PVC heat stabilizer.

Study of the effectiveness of magnesium-zinc stabilizer based on pentaerythritol in the roll-calender processing of polyvinyl chloride

A comparative analysis of a magnesium-zinc stabilizer based on pentaerythritol and a standard calcium-zinc stabilizer based on stearic acid was carried out. The influence of the ratio of pentaerythritol magnesium (PenMg) to pentaerythritol zinc (PenZn) on the thermal and thermo-mechanical stability of polyvinyl chloride (PVC) is considered.

Improvement of photostability and thermal stability of PVC by carbon quantum dots loaded on TiO2

AbstractTitanium dioxide (TiO2) has a strong oxidation effect when absorbing ultraviolet light. Therefore, when TiO2 is used as a light stabilizer in polyvinyl chloride (PVC), it will cause the photodegradation of PVC. Herein, carbon quantum dots (CQDs) coated TiO2 composite (TiO2@CQDs) was prepared by a one‐step hydrothermal method. The prepared TiO2@CQDs were characterized by transmission electron microscopy (TEM), UV–Vis spectroscopy, X‐ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and X‐ray diffraction (XRD). The photostability of PVC film containing TiO2@CQDs was investigated via photodegradation conductivity test, weight loss rate test, and ultraviolet aging test. Due to the down‐conversion effect of CQDs under ultraviolet light, its existence can alleviate the photoaging of PVC. In addition, the thermal stability of PVC containing TiO2@CQDs was studied by conductivity tests and oven thermal aging tests. The presence of CQDs significantly improved the thermal stability of PVC. Meanwhile, the HCl absorption capacity of CQDs could reach 30.8 mg/gcat. According to the DFT calculations, this high absorption capacity is attributed to the HCl immobilization effect via forming hydrogen bonds between HCl and the keto oxygen, carboxyl keto oxygen in CQDs. The hydroxyl group in CQDs could also combine ZnCl2 by forming a coordination bond.

Preparation of rare-earth terephthalic acid stabilizer and its effect on thermal stability of polyvinyl chloride

Preparation of rare-earth terephthalic acid stabilizer and its effect on thermal stability of polyvinyl chloride

A new organic zinc thermal stabilizer containing two kinds of anions with excellent thermal stability on polyvinyl chloride by multistep substitution

AbstractA new kind of highly efficient organic zinc thermal stabilizer for polyvinyl chloride (PVC), zinc arginine stearate [Zn(Arg)(St)], is designed by introducing the arginine and stearate to the same zinc atoms to regulate the binding energy between anions and cation. Gaussian soft is used to calculate the binding energy. The results of Fourier transform infrared spectra, elemental analysis, thermogravimetric analysis, and differential scanning calorimetry show that Zn(Arg)(St) has been successfully synthesized. Zn(Arg)(St) stabilized PVC displays excellent Congo red, static and dynamic thermal stability time, especially the excellent initial whiteness and whiteness retention time. The thermal stability mechanism of Zn(Arg)(St) attributes to the different binding energy between the two anions and zinc cation, which results in Zn(Arg)(St) continuously replacing the unstable chlorine atoms step by step by Arg and St anions. Moreover, the amino group in Arg could complex ZnCl2 to inhibit the “zinc burning” effect, and the guanidine group could absorb HCl to inhibit the “autocatalytic effect” of HCl. In addition, Zn(Arg)(St) has a remarkable lubrication effect, which also enhances the thermal stability of PVC. Thus, Zn(Arg)(St) is an environmentally friendly thermal stabilizer for PVC with an excellent thermal stability effect. Importantly, this work also proposes a new method to design highly efficient thermal stabilizers for PVC.

Novel polyvinyl chloride composite via hybrid metal-organic framework grafted polyethyleneimine and layered double hydroxide incorporation: Thermal, rheological, and electrical properties

Improving the heat stabilization of polyvinyl chloride (PVC) is of great importance, particularly for its use in electrical insulation. In this study, a novel zeolitic imidazole framework (ZIF-8) was modified using polyethyleneimine (PEI) and layered double hydroxide (LDH) to create a new PVC heat stabilizer. The heat stability of PVC was analyzed using oven, Congo red, and thermogravimetric analysis (TGA) tests, with the dosage of modified ZIF-8 found to have a significant impact on PVC's heat stability (increasing from 33 to 58 min). Additionally, con-calorimetry was performed to evaluate the effect of LDH modification on ZIF-8′s flame retardancy, revealing that LDH delayed flame emission from 255 to 560 s. Lastly, volume resistance and mechanical tests were conducted to assess the effect of the novel ZIF-8 modification on PVC compound properties.

Enhancing the Initial Whiteness and Long-Term Thermal Stability of Polyvinyl Chloride by Utilizing Layered Double Hydroxides with Low Surface Basicity

This study investigated the impact of surface basicity on the performance of layered double hydroxides (LDHs) as heat stabilizers for polyvinyl chloride (PVC). LDHs with varying surface basicity were synthesized and characterized using XRD, SEM, BET, and CO2-TPD. The LDHs were then combined with zinc stearate and dibenzoylmethane to create an environmentally friendly heat stabilizer and added to PVC. The resulting PVC composites were evaluated for thermal stability using the oven-aging method. The results showed that a lower Mg/Al molar ratio (2.0) improved the initial whiteness and long-term thermal stability of PVC composites compared to higher ratios (2.5, 3.0, and 3.5). Replacing Mg with Zn in the LDHs had a similar effect to that of reducing the Mg/Al ratio. Crosslinking the laminae of LDHs with 5% silane coupling agent KH-560 reduced the surface basicity of LDHs by 79%, increasing the chromaticity index, b*, and thermal stability time of PVC composites by 48% and 14%, respectively. A descriptive relationship was established between the structure and surface basicity of LDHs and the initial whiteness and long-term thermal stability of PVC composites.

Organotin Antifouling Compounds and Sex-Steroid Nuclear Receptor Perturbation: Some Structural Insights.

Organotin compounds (OTCs) are a commercially important group of organometallic compounds of tin used globally as polyvinyl chloride stabilizers and marine antifouling biocides. Worldwide use of OTCs has resulted in their ubiquitous presence in ecosystems across all the continents. OTCs have metabolic and endocrine disrupting effects in marine and terrestrial organisms. Thus, harmful OTCs (tributyltin) have been banned by the International Convention on the Control of Harmful Antifouling Systems since 2008. However, continued manufacturing by non-member countries poses a substantial risk for animal and human health. In this study, structural binding of common commercial OTCs, tributyltin (TBT), dibutyltin (DBT), monobutyltin (MBT), triphenyltin (TPT), diphenyltin (DPT), monophenyltin (MPT), and azocyclotin (ACT) against sex-steroid nuclear receptors, androgen receptor (AR), and estrogen receptors (ERα, ERβ) was performed using molecular docking and MD simulation. TBT, DBT, DPT, and MPT bound deep within the binding sites of AR, ERα, and Erβ, showing good dock score, binding energy and dissociation constants that were comparable to bound native ligands, testosterone and estradiol. The stability of docking complex was shown by MD simulation of organotin/receptor complex with RMSD, RMSF, Rg, and SASA plots showing stable interaction, low deviation, and compactness of the complex. A high commonality (50-100%) of interacting residues of ERα and ERβ for the docked ligands and bound native ligand (estradiol) indicated that the organotin compounds bound in the same binding site of the receptor as the native ligand. The results suggested that organotins may interfere with the natural steroid/receptor binding and perturb steroid signaling.

Preparation and performance of PVC long‐term heat stabilizer based on the synergistic effect of uracil and metal complexes

AbstractIn order to improve the deficiency of traditional polyvinyl chloride (PVC) heat stabilizer, triazole‐based zinc‐containing complex (abbreviated as [Zn(ttr)(OAc)]) with good compatibility with PVC and a strong ability to absorb HCl was prepared in this paper, which was characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscope (SEM) and thermogravimetric analysis (TGA). PVC sheets were prepared by mixing PVC with composite heat stabilizer (DAJ) composed of [Zn(ttr)(OAc)] and 1,3‐dimethyl‐6‐aminouracil (DAU). Different kinds and amounts of common auxiliary heat stabilizers were selected and added to the DAJ system to study the effect of thermally stable system on PVC by Congo red test, Discoloration test, Dynamic thermal stability test, SEM, TGA and Transmittance test and the relevant mechanism was explored. The PVC sheets with DAJ blended by 1.2 phr DAU and 0.8 phr [Zn(ttr)(OAc)] showed relatively excellent coloring properties, long‐term thermal stability, and high light transmittance. Compared with dibenzoylmethane (DBM), 0.5 phr sorbitol and 1.5 phr epoxy soybean oil (ESBO)/Antioxidant 168 showed good synergistic effect with DAJ. Due to the polyhydroxy nature of sorbitol, the thermal stability of PVC was significantly improved, and the transmittance of PVC benefited from the similar miscibility of ESBO long chain. This was also confirmed by TGA and SEM of PVC sheet.

Study on surface modification of ground calcium carbonate with novel modifier and its PVC filling performance

Ground calcium carbonate (GCC) are versatile due to low cost, low energy consumption, simple processing, and environmental protection. In this study, the novel modifier JST9001 was utilized for dry modification of GCC, and then polyvinyl chloride (PVC) based composites including modified GCC particles were fabricated to examine the mechanical properties. The performance indexes of activation index, wetting contact angle and dispersion stability showed that modified GCC obtained excellent modification effect at low modifier dosage (0.50 wt%). And the XRD, FT-TR, TGA, XPS and NMR measurements indicated that the JST9001 was coated on the surface of GCC particles successfully. The mechanical properties testing results demonstrated that 0.50 wt% JST9001 modified-GCC/PVC composites displayed better bending strength, bending modulus, tensile strength, tensile modulus, and impact strength compared with other dosage JST9001 modified-GCC/PVC composites. In addition, the filling content of modified GCC can reach 60 wt% in the premise of ensuring excellent mechanical properties with bending modulus of 3266.92 MPa, bending strength of 39.89 MPa, tensile modulus of 3092.13 MPa, tensile strength of 35.49 MPa and impact strength of 71.88 MPa, realizing the high filling of the modified GCC. Moreover, the modification of GCC remarkably improved the thermal stability of PVC based composites. Overall, novel modifier has the potential to reduce the cost and improve the performance of GCC/PVC composites. • Novel JST9001 modifier was used to modify GCC. • Optimal modification effect was gained at the low dosage (0.50 wt%). • The filling content of GCC can reach 60 wt% in the PVC-based composites. • The obtained PVC-based composites have good mechanical properties. • The study has potential to apply GCC in plastics and other industries.