Internally plasticized PVC by four different green plasticizer compounds

Water-Doped Brønsted Acidic Protic Ionic Liquids for Enhanced Tributyl Citrate Synthesis in a Two-Phase Esterification System

Tributyl citrate (TBC) plays a crucial role as a plasticizer, enhancing the flexibility of polymers such as polyvinyl chloride. Its biodegradability and non-toxic nature contribute to eco-friendly appeal, making it a preferred additive in diverse industries, including food packaging, medical devices, toys, and consumer goods. Herein, a method for the synthesis of TBC using inexpensive Brønsted acidic protic ionic liquids (ILs) in a two-phase reaction system is presented. The esterification process is carried out with high yield (>99 %), selectivity (up to 98 %) and short reaction time of 2 h. The catalyst in the form of IL shows excellent performance and stability, desirable for industrial applications.

Composition and release rates of chemicals in inkjet fabrics determined by non-targeted screening and targeted analysis

Unveiling composition and release rates of chemicals in chemical-intensive products (CIPs) such as inkjet fabrics that are applied extensively in advertising and publicizing industries, is of importance to sound management of chemicals. This study tentatively identified 212 compounds from 69 inkjet fabric samples using gas chromatograph coupled with quadrupole time-of-flight mass spectrometry (GC-QTOF-MS). Contents of six phthalate esters (PAEs) were quantified to range from 3.0 × 102 mg/kg to 3.1 × 105 mg/kg with GC-MS. Bis(2-ethylhexyl) phthalate was predominantly detected to average 96 g/kg. The inkjet fabrics collected from southern China contained fewer non-intentionally added substances (NIASs) than from northern China. Annual mass release rates (RM) of the 6 PAEs from inkjet fabrics to air were estimated to range from 1.4 × 10-2 kg/year to 2.8 × 104 kg/year in China in 2020, and the mean indoor RM was comparable with the outdoor one. Equilibrium partition coefficients of the compounds between the product and air, ambient temperature, and concentrations of chemicals in the product, are key factors leading to RM with the high variance. The findings indicate that contents of the NIASs in the CIPs should be minimized, and the refining concept should be adopted in design of the CIPs, so as to control the release of chemicals from the CIPs.

Thermal/Blue Light Induced Cross-Linking of Acrylic Coatings with Diazo Compounds

The thermal curing of industrial coatings (e.g., car painting and metal coil coatings) is accompanied by a substantial energy consumption due to the intrinsically high temperatures required during the curing process. Therefore, the development of new photochemical curing processes-preferably using visible light-is in high demand. This work describes new diazo-based cross-linkers that can be used to photocure acrylic coatings using blue light. This work demonstrates that the structure of the tethered diazo compounds influences the cross-linking efficiency, finding that side reactions are suppressed upon engineering greater molecular flexibility. Importantly, this work shows that these diazo compounds can be employed as either thermal or photochemical cross-linkers, exhibiting identical crosslinking performances. The performance of diazo-cross-linked coatings is evaluated to reveal excellent water resistance and demonstrably similar material properties to UV-cured acrylates. These studies pave the way for further usage of diazo-functionalized cross-linkers in the curing of paints and coatings.

Investigation of Cinnamic Acid Derivatives as Alternative Plasticizers for Improved Ductility of Polyvinyl Chloride Films

This study investigates the viability of cinnamic acid derivatives as alternative plasticizers for polyvinyl chloride (PVC) films by addressing concerns about conventional phthalate-based options that pose health and environmental risks. By theoretical modeling, this research evaluates the compatibility between various cinnamic acid-based plasticizers and the PVC matrix, which suggests their potential effectiveness. Additionally, the incorporation of these plasticizers notably enhances the tensile properties of PVC films, particularly in terms of ductility and elongation at break by surpassing the neat PVC. Moreover, cinnamic acid-based plasticizers induce a drop in the glass transition temperature and storage modulus by, thereby, enhancing flexibility and reducing brittleness in the material. Although a slight reduction in the onset degradation temperature is observed, it does not impede the industrial processing of PVC plastisols at temperatures up to 190 °C. Optically, plasticized films exhibit high transparency with minimal UV and visible light absorption, which renders them suitable for applications necessitating clarity. The water vapor transmission rate analysis indicates increased permeability, influenced by molecular volumes. Atomic force microscopy reveals a compacted, homogeneous surface structure in most plasticized films, which signifies improved film quality. Thus, utilizing cinnamic acid derivatives as PVC plasticizers offers substantial mechanical and structural benefits, while compatibility ensures effective integration by contributing to environmentally sustainable PVC formulations with enhanced performance.

Thermomechanical Properties of Nontoxic Plasticizers for Polyvinyl Chloride Predicted from Molecular Dynamics Simulations

Environmental and toxicity concerns dictate replacement of di(2-ethylhexyl) phthalate (DEHP) plasticizer used to impart flexibility and thermal stability to polyvinyl chloride (PVC). Potential alternatives to DEHP in PVC include diheptyl succinate (DHS), diethyl adipate (DEA), 1,4-butanediol dibenzoate (1,4-BDB), and dibutyl sebacate (DBS). To examine whether that these bio-based plasticizers can compete with DEHP, we need to compare their tensile, mechanical, and diffusional properties. This work focuses on predicting the effect these plasticizers have on T_g, Young's modulus, shear modulus, fractional free volume, and diffusion for PVC-plasticizer systems. Where data was available, the results from this study are in good agreement with the experiment; we conclude that DBS and DHS are most promising green plasticizers for PVC, since they have properties comparable to DEHP but not the environmental and toxicity concerns.

Effects of UV radiation on natural and synthetic materials

The deleterious effects of solar ultraviolet (UV) radiation on construction materials, especially wood and plastics, and the consequent impacts on their useful lifetimes, are well documented in scientific literature. Any future increase in solar UV radiation and ambient temperature due to climate change will therefore shorten service lifetimes of materials, which will require higher levels of stabilisation or other interventions to maintain their lifetimes at the present levels. The implementation of the Montreal Protocol and its amendments on substances that deplete the ozone layer, controls the solar UV-B radiation received on Earth. This current quadrennial assessment provides a comprehensive update on the deleterious effects of solar UV radiation on the durability of natural and synthetic materials, as well as recent innovations in better stabilising of materials against solar UV radiation-induced damage. Pertinent emerging technologies for wood and plastics used in construction, composite materials used in construction, textile fibres, comfort fabric, and photovoltaic materials, are addressed in detail. Also addressed are the trends in technology designed to increase sustainability via replacing toxic, unsustainable, legacy additives with 'greener' benign substitutes that may indirectly affect the UV stability of the redesigned materials. An emerging class of efficient photostabilisers are the nanoscale particles that include oxide fillers and nanocarbons used in high-performance composites, which provide good UV stability to materials. They also allow the design of UV-shielding fabric materials with impressive UV protection factors. An emerging environmental issue related to the photodegradation of plastics is the generation of ubiquitous micro-scale particles from plastic litter exposed to solar UV radiation.

Incorporation of ultrathin porous metal-free graphite carbon nitride nanosheets in polyvinyl chloride for efficient photodegradation

Solid-phase photocatalytic degradation of waste plastics is one of the promising approaches to solve the "white pollution" problem. In this work, a low cost, metal-free, environmentally friendly organic photocatalyst, graphite carbon nitride (g-C₃N₄), was used for the first time to successfully enhance the photodegradation of polyvinyl chloride (PVC) under simulated sunlight from its visible light photocatalytic capability, while its organic nature and abundant surface functional groups were beneficial for its good dispersion in plastics. It was found that the ultrathin porous g-C₃N₄ nanosheet synthesized from urea (the UCN sample) had much stronger photodegradation effect in PVC/g-C₃N₄ composite films than its thick block counterpart synthesized with melamine (the MCN sample) due to its larger specific surface area, higher pore volume, and enhanced photogenerated charge carrier separation. With the incorporation of only 1 wt% UCN sample into PVC, its mechanical properties were largely enhanced with the tensile strength increase of ∼ 45% and the elongation at break increase of ∼ 72%, and its weight loss increased ∼ 58% after 120 h irradiation in the weather resistance test chamber. ^·O₂^- and h⁺ produced by the UCN sample were found as the main active species in the photocatalytic degradation of PVC to dechlorinate PVC and decompose its long-chain molecules into short-chain small molecules until its final degradation into CO₂ and H₂O under ideal conditions.

Self-Plasticized PVC Prepared by Introducing Fatty Acid to the PVC with Triglycidyl Isocyanurate as an Intermediate Bridge

The phthalate-free self-plasticization of poly(vinyl chloride) (PVC) conforms to the concept of green chemistry. In this work, phthalate-free, biocontaining, self-plasticized PVC with nonmigration (4-an-TG-X-PVC; X = R, P, or O) was prepared by covalent attachment of ricinoleic acid, palmitic acid, and oleic acid, respectively, to the PVC matrix with 4-aminothiophenol and triglycidyl isocyanurate (TGIC) as intermediate bridges. 4-Aminothiophenol and TGIC acted as the nucleophilic reagent and the thermally stable substance, respectively. The 4-an-TG-X-PVC was observed by diverse characterization methods. Specifically, Fourier transform infrared spectra, ¹H nuclear magnetic resonance, gel permeation chromatography, and migration stability tests proved the successful synthesis of 4-an-TG-X-PVC. Compared to the neat PVC, the mechanical property of 4-an-TG-X-PVC is better. The glass transition temperature (T _g) of PVC is 81.24 °C, while that of 4-an-TG-X-PVC decreased to 41.88, 31.49, and 46.91 °C. The 4-an-TG-X-PVC showed higher elongation at break and lower tensile strength than neat PVC. Simultaneously, the thermal property of 4-an-TG-X-PVC got a boost. Thermogravimetry-infrared and thermogravimetry-mass spectrometry showed that 4-an-TG-X-PVC released less HCl than neat PVC in a thermal environment. Discoloration experiments demonstrated that 4-an-TG-P-PVC had better heat stabilization and better color than 4-an-TG-O-PVC and 4-an-TG-R-PVC. This work provides a viable solution to the dependence on phthalates, reduced human health and ecological risks, and endowed PVC with improved thermal stability and nonmigration performance.

Metal-Free Click Modification of Triple Bond-Containing Polyester with Azide-Functionalized Vegetable Oil: Plasticization and Tunable Solvent Adsorption

Pressure from environmental nongovernmental organizations and the public has accelerated research on the development of innovative and renewable polymers and additives. Recently, biobased "green" plasticizers that can be covalently attached to replace toxic and migratory phthalate-based plasticizers have gained a lot of attention from researchers. In this work, we prepared an azide-functionalized soybean oil derivative (AzSBO) and investigated whether it can be used as a plasticizer. We covalently attached AzSBO to an electron-deficient triple-bond-containing polyester via a metal-free azide-alkyne click reaction. The thermal, mechanical, and solvent absorption behaviors of different amounts of azidated oil-containing polyesters were determined. Moreover, the plasticization efficiency of AzSBO was compared with the commercial plasticizers bis(2-ethylhexyl) phthalate and epoxidized soybean oil. At relatively lower AzSBO ratios, the degree of cross-linking was higher and thus the plasticization was less pronounced but the solvent resistance was significantly improved. As the ratio of AzSBO was increased, the glass transition temperature of the pristine polymer decreased up to 31 °C from 57 °C. Furthermore, the incorporation of AzSBO also improved the thermal properties and 20% AzSBO addition led to a 60 °C increase in the maximum weight loss temperature.

Development of a Highly Efficient Environmentally Friendly Plasticizer

The purpose of this work is the synthesis of adipic acid ester and the study of the possibility of its use as a PVC plasticizer. The resulting butyl phenoxyethyl adipate was characterized by Fourier-transform infrared spectrometry, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The compatibility, effectiveness and plasticizing effect of butyl phenoxyethyl adipate in comparison with dioctylphthalate (DOP) were determined. The new environmentally friendly plasticizer has good compatibility with PVC and high thermal stability. The effectiveness of the plasticizing action of adipate based on the glass-transition temperature was 132.2 °C in relation to pure PVC and 7.7 °C in comparison to compounds based on DOP. An increase in the fluidity of the melt of polyvinyl chloride (PVC) compounds in the temperature range of 160–205 °C by 19–50% confirms a decrease in the energy intensity of the processes of manufacturing and the processing of polymer materials containing a new additive.

Effective, Environmentally Friendly PVC Plasticizers Based on Succinic Acid

The plasticizers used in this study were synthesized from renewable raw materials using succinic acid, oleic acid, and propylene glycol. Four environmentally friendly plasticizer samples were obtained; their chemical structures and compositions were confirmed by gas chromatography (GC) and infrared spectroscopy (FT–IR) analyses, and their physicochemical properties and thermal stability (TGA analysis) were investigated. The obtained ester mixtures were used as poly(vinyl chloride) (PVC) plasticizers and their plasticization efficiency was determined in comparison to traditional, commercially available phthalate plasticizers, such as DEHP (di(2-ethylhexyl phthalate) and DINP (diisononyl phthalate). Mechanical properties and migration resistance were determined for soft PVC with the use of three concentrations of plasticizers (40 PHR, 50 PHR, and 60 PHR). It was observed that the obtained plasticizers exhibited the same plasticization efficiency and were characterized with good mechanical and physical properties in comparison to commercial plasticizers. The tensile strength was approx. 19 MPa, while the elongation at break was approx. 250% for all tested plasticizers at a concentration of 50 PHR. Furthermore, plasticizer migration studies showed that the synthesized plasticizers had excellent resistance to plasticizer leaching. The best migration test result obtained was 70% lower than that for DEHP or DINP. The ester mixture that was found to be the most favorable plasticizer was characterized by good thermal and thermo-oxidative stability (5% weight loss temperature: 227.8 °C in air and 261.1 °C in nitrogen). The results of the research clearly indicate that the synthesized esters can provide a green alternative to toxic phthalate plasticizers.

A strategy to prepare internally-plasticized poly(vinyl chloride) by grafting castor oil onto the PVC chain with three different isocyanates as intermediate bridges

Three types of isocyanates were selected as intermediate bridges to graft castor oil onto PVC to realize the internal-plasticization in PVC. This method does not require pretreatment of castor oil.

Flotator Oxal as the plasticizer for suspension PVC

Flotator Oxal, a mixture of dioxane ethers and alcohols, was studied as a plasticizer for suspension PVC in comparison with the well-known dibutyl phthalate (DBP) and di-(2-ethylhexyl) phthalate (DOP). The rheological parameters and gelation ability of the plasticizers were determined, and the values of the storage modulus and tangent of mechanical loss angle in the glassy and rubbery states were measured by the DMA method, and the glass transition temperatures were determined. The deformation-strength properties and rigidity of polymer films were tested before and after light-thermal aging. Oxal was shown to reveal a fairly low viscosity and high gelation properties in relation to PVC. At the same time, its ability to reduce the glass transition temperature and elasticize the polymer in the glassy and rubbery state is somewhat lower than that of phthalate plasticizers. PVC samples plasticized with DBP have the highest resistance to light-thermal aging.

Developments of biobased plasticizers for compostable polymers in the green packaging applications: A review

The demand for biobased materials for various end-uses in the bioplastic industry is substantially growing due to increasing awareness of health and environmental concerns, along with the toxicity of synthetic plasticizers such as phthalates. This fact has stimulated new regulations requiring the replacement of synthetic conventional plasticizers, particularly for packaging applications. Biobased plasticizers have recently been considered as essential additives, which may be used during the processing of compostable polymers to enormously boost biobased packaging applications. The development and utilization of biobased plasticizers derived from epoxidized soybean oil, castor oil, cardanol, citrate, and isosorbide have been broadly investigated. The synthesis of biobased plasticizers derived from renewable feedstocks and their impact on packaging material performance have been emphasized. Moreover, the effect of biobased plasticizer concentration, interaction, and compatibility on the polymer properties has been examined. Recent developments have resulted in the replacement of synthetic plasticizers by biobased counterparts. Particularly, this has been the case for some biodegradable thermoplastics-based packaging applications.

Proof-of-Concept of Detection of Counterfeit Medicine through Polymeric Materials Analysis of Plastics Packaging

The detection of counterfeit pharmaceuticals is always a major challenge, but the early detection of counterfeit medicine in a country will reduce the fatal risk among consumers. Technically, fast laboratory testing is vital to develop an effective surveillance and monitoring system of counterfeit medicines. This study proposed the combination of Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) and Differential Scanning Calorimetry (DSC) for the quick detection of counterfeit medicines, through the polymer analysis of blister packaging materials. A sample set containing three sets of original and counterfeit medicine was analyzed using ATR-FTIR and DSC, while the spectra from ATR-FTIR were employed as a fingerprint for the polymer characterization. Intending to analyze the polymeric material of each sample, DSC was set at a heating rate of 10 °C min^-l and within a temperature range of 0- 400 °C, with nitrogen as a purge gas at a flow rate of 20 ml min^-an. The ATR-FTIR spectra revealed the chemical characteristics of the plastic packaging of fake and original medicines. Further analysis of the counterfeit medicine's packaging with DSC exhibited a distinct difference from the original due to the composition of polymers in the packaging material used. Overall, this study confirmed that the rapid analysis of polymeric materials through ATR-FTIR and comparing DSC thermograms of the plastic in their packaging effectively distinguished counterfeit drug products.

Recent Attempts in the Design of Efficient PVC Plasticizers with Reduced Migration

This paper reviews the current trends in replacing commonly used plasticizers in poly(vinyl chloride), PVC, formulations by new compounds with reduced migration, leading to the enhancement in mechanical properties and better plasticizing efficiency. Novel plasticizers have been divided into three groups depending on the replacement strategy, i.e., total replacement, partial replacement, and internal plasticizers. Chemical and physical properties of PVC formulations containing a wide range of plasticizers have been compared, allowing observance of the improvements in polymer performance in comparison to PVC plasticized with conventionally applied bis(2-ethylhexyl) phthalate, di-n-octyl phthalate, bis(2-ethylhexyl) terephthalate and di-n-octyl terephthalate. Among a variety of newly developed plasticizers, we have indicated those presenting excellent migration resistance and advantageous mechanical properties, as well as those derived from natural sources. A separate chapter has been dedicated to the description of a synergistic effect of a mixture of two plasticizers, primary and secondary, that benefits in migration suppression when secondary plasticizer is added to PVC blend.