Effect of ketal group in castor oil acid-based plasticizer on the properties of poly(vinyl chloride)

Two castor oil acid esters containing a ketal or ketone group (KCL or CL), as alternative plasticizers for poly(vinyl chloride) (PVC), were prepared. The structures were confirmed by ¹H NMR and FTIR spectroscopies. The effects of the presence of a ketal or ketone group in these compounds on PVC plasticization were examined. The DMA and SEM results showed that both plasticizers were miscible with PVC and exhibited excellent plasticizing properties, compared to those of dioctyl phthalate (DOP). The PVC plasticized by KCL displayed a lower T_g value of 20.6 ° C, which was lower than that of PVC plasticized with DOP (22.3 ° C) and PVC plasticized with CL (40.5 ° C). Tensile tests indicated that PVC plasticized using KCL showed a 37% higher of elongation at break than PVC plasticized by CL and 30% higher than PVC plasticized by DOP. The plasticizing mechanism was also investigated. Moreover, exudation, volatility, and extraction tests, along with TGA indicated that the presence of ketal groups effectively improved the migration resistance of plasticizer and the thermal stability of PVC blends. Taken together, introducing ketal groups into plasticizer might be an effective strategy for improving its plasticizing efficiency.     

Epoxidized dimeric acid methyl ester derived from rubber seed oil and its application as secondary plasticizer

A novel plasticizer epoxidized dimeric acid methyl ester (EDAMe) based on rubber seed oil was synthesized. Chemical structure of EDAMe was characterized by Fourier transform infrared (FTIR) and gel permeation chromatography (GPC). Effects of EDAMe as secondary plasticizer and its substitution of commercial plasticizer dioctyl terephthalate (DOTP) in soft poly(vinyl chloride) (PVC) films were studied. The thermal properties, mechanical properties and migration stabilities of PVC films were explored with DMA, TG, TG–FTIR, dynamic thermal stability analysis, tensile and migration tests. The results indicated that the epoxidized rubber seed oil based ester has significantly higher thermal stability than DOTP. When DOTP was substituted with 20% (m/m) EDAMe, the results of initial decomposition temperature (T_i), 10% and 50% mass loss temperatures (T₁₀ and T₅₀), and the first maximum weight‐loss temperature rate (T_P1) reached 267.2 °C, 263.5 °C, 307.3 °C and 298.9 °C, respectively. Furthermore, flexibility of the obtained PVC films enhanced significantly with the adding of EDAMe. The migration stabilities of EDAMe was also investigated and showed good migration resistance. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43668.     

Sustainable synthesis of bio‐based hyperbranched ester and its application for preparing soft polyvinyl chloride materials

In this study, bio‐based hyperbranched ester was synthesized from castor oil. The chemical structure of the bio‐based hyperbranched ester obtained was characterized with Fourier transform infrared and ¹H NMR spectra. Soft polyvinyl chloride (PVC) materials were prepared via thermoplastic blending at 160 °C using bio‐based hyperbranched ester as plasticizer. The performances including the thermal stability, glass transition temperature (T_g), crystallinity, tensile properties, solvent extraction resistance and volatility resistance of soft PVC materials incorporating bio‐based hyperbranched ester were investigated and compared with the traditional plasticizer dioctyl phthalate (DOP). The results showed that bio‐based hyperbranched ester enhanced the thermal stability of the PVC materials. The T_g of PVC incorporating bio‐based hyperbranched ester was 23 °C, lower than that of PVC/DOP materials at 28 °C. Bio‐based hyperbranched ester showed a better plasticizing effect, solvent extraction resistance and volatility resistance than DOP. The plasticizing mechanism is also discussed. © 2018 Society of Chemical Industry     

Rosin‐derived poly(vinyl chloride) plasticizer: Synthesis,structure, and properties

In this work, rosin‐based plasticizer was synthesized by Diels–Alder (DA) and esterification. First, the maleopimaric acid (RT) was obtained by DA between the double bond of rosin and maleic anhydride. Then, the carboxyl group and anhydride group of RT was esterified with tetrahydro geraniol to obtain the rosin‐based polyacid esters (RTT) under the catalysis of p‐toluene sulfonic acid. The structure of RT and RTT was detected by FTIR and ¹H‐NMR. RTT was used as main plasticizer to obtain plasticized polyvinyl chloride (PVC) materials and compared with DOP. The results showed that RTT improved the thermal stability and reduced T_g of PVC film. Plasticized PVC films had excellent mechanical properties with the elastic modulus of ?4,793.67 MPa and tensile strength of ?111.86 MPa, higher than that of pure PVC and DOP‐6. RTT showed better volatility stability, migration, and solvent extraction in PVC compared to DOP. J. VINYL ADDIT. TECHNOL., 26:180–186, 2020. © 2019 Society of Plastics Engineers     

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

A 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 T_g 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.     

Dielectric and mechanical properties of poly(vinyl chloride)–dioctylphthalate systems

The mechanical properties, tensile strength, and elongation were investigated for poly(vinyl chloride) (PVC) samples mixed with dioctylphthalate (DOP) at concentrations from 0 to 100 parts per hundred parts PVC at 23°C. It was found that the tensile strength decreased with the increase of concentration, and the elongation was increased until a concentration of 30 DOP content, and then decreased. This leads to the suggestion that intermolecular plasticization is dominant until 30 DOP content, while interstructural plasticization is prevailing for higher concentrations. The permittivity ε′ and the dielectric loss factor ε″ of the same samples have been measured in the frequency range 10²–10⁵ Hz at temperatures from 3 to 96°C. Results show that as the DOP content increases in PVC, the dielectric absorption becomes broader, and the glass transition temperature T_g is lowered. The magnitude of the loss peak decreases with an increase of DOP content to a minimum at concentrations from 40 to 60 DOP content. At higher concentrations the loss peak is increased and T_g is unaltered. Another absorption was observed at 100 Hz and at high temperatures, which was attributed to Maxwell–Wagner effect or direct current conductivity or both of them. It was found that the sample containing 40 parts DOP in 100 parts PVC possesses the best mechanical and electrical properties.     

Synthesis of difuran diesters from furfural,and their evaluation as plasticizers for polyvinyl chloride

The compounds 1,1-bis[5-(2-ethylhexyl, 2-octyl, hexyl, and butyl)carboxylate-2-furyl)ethane, and 5,5′-dihexylcarboxylate-2,2′ bifuran were synthesized from furfural and characterized for their plasticizing abilities toward polyvinyl chloride (PVC) by dynamic mechanical thermal analyses (DMTA) with di-(2-ethylhexyl)phthalate (DOP)as the standard of reference. DMTA gave values for the depression of the glass-transition temperature (T_g) per mass fraction of plasticizer, and it also yielded a set of parameters, relative to those of DOP, which describe the compatability of the furan diesters with PVC. These values are compared to those of DOP and furan diesters incorporating only one furan ring in the molecular structure, which have previously been tested by this method. The difuran plasticizers are less efficient in lowering T_g than the monofuran plasticizers or DOP, with 1,1-bis[5-(2-octyl)carboxylate-2-furyl]ethane the least efficient and 1,1-bis(5-hexylcarboxylate-2-furyl)ethane the most efficient. On average the compatability toward PVC is better than that of DOP, and similar to that of analogous monofuran structures. © 1995 John Wiley & Sons, Inc.     

Microstructure evolution of ammonia‐catalyzed phenolic resin during thermooxidative aging

The thermooxidative aging of ammonia‐catalyzed phenolic resin for 30 days at 60–170°C was investigated in this article. The aging mechanism and thermal properties of the phenolic resin during thermooxidative aging were described by thermogravimetry (TG)–Fourier transform infrared (FTIR) spectroscopy, attenuated total reflectance (ATR)–FTIR spectroscopy, and dynamic mechanical thermal analysis. The results show that the C? N bond decomposed into ammonia and the dehydration condensation between the residual hydroxyl groups occurred during the thermooxidative aging. Because of the presence of oxygen, the methylene bridges were oxidized into carbonyl groups. After aging for 30 days, the mass loss ratio reached 4.50%. The results of weight change at high temperatures coincided with the results of TG–FTIR spectroscopy and ATR–FTIR spectroscopy. The glass‐transition temperature (T_g) increased from 240 to 312°C after thermooxidative aging for 30 days, which revealed the postcuring of phenolic resins. In addition, an empirical equation between the weight change ratio and T_g was obtained. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis and evaluation of dialkyl furan-2,5-dicarboxylates as plasticizers for PVC

Di(2-ethylhexyl), di(2-octyl), dihexyl, and dibutyl furan-2,5-dicarboxylate were synthesized from furfural and characterized for their plasticizing abilities toward PVC by dynamic mechanical thermal analysis (DMTA) with di(2-ethylhexyl) phthalate (DOP) as the standard of reference. DMTA gave values for the depression of the glass transition temperature (T_g) per mass fraction of plasticizer, and it also yielded a set of parameters, relative to those for DOP, which describe the compatibility of the furan diesters with PVC. The efficiency in lowering T_g as exhibited by di(2-ethylhexyl) furan-2,5-dicarboxylate is similar to that of its benzenoid analog, DOP, and was determined at 2.41 and 2.45°C per mass % plasticizer, respectively. All four furan diesters were found to be more compatible toward PVC than toward DOP, with dibutyl furan-2,5-dicarboxylate the most highly compatible. © 1994 John Wiley & Sons, Inc.     

Epoxidized castor oil-based diglycidyl-phthalate plasticizer: Synthesis and thermal stabilizing effects on poly(vinyl chloride)

Epoxidized castor oil-based diglycidyl-phthalate (ECODP) was synthesized and incorporated into poly(vinyl chloride) (PVC) for the first time. The chemical structure of the ECODP was confirmed. The plasticizing effects of ECODP as a replacement for commercial plasticizer dioctyl phthalate (DOP) were investigated. The thermal stability and mechanical properties of PVC films before and after aging were investigated using thermogravimetric analysis (TGA), TGA-FTIR analysis, dynamic mechanical analysis (DMA), and tensile tests. The results indicated that PVC films plasticized with ECODP significantly improved thermal stability, compatibility, and flexibility. When DOP was substituted with ECODP completely, the initial decomposition temperature, 5, 10, 50, and 70% mass loss temperatures (T_i, T₅, T₁₀, T₅₀, and T₇₀) increased by 24.7, 38.9, 32.0, 30.3, and 102.7 °C, respectively. The functional mechanism of the ECODP as a thermal stabilizing plasticizer and the plasticization mechanism of PVC composites were also investigated. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47142.     

Effect of poly(vinyl chloride)/chlorinated polyethylene blend composition on thermal stability

Blends of poly(vinyl chloride) (PVC) with different ratios of chlorinated polyethylene (CPE) were degradated by the thermogravimetric method under dynamic conditions (50–600°C) in an inert atmosphere. The effect of the miscibility and composition of the PVC/CPE blends on the thermal stability were investigated. DSC curves of the blends show neither a shift of the PVC glass transition temperature nor a shift of the CPE melting temperature, which means that these blends are heterogeneous. The characteristics of the TG curves were determined, some of which (T_1%,T_5%, Δm₁) can be used as indicators of the thermal stability of the blend. The apparent activation energy of PVC dehydrochlorination in the blends was also calculated. Comparison of the experimental TG curves and TG curves predicted by the additivity rule indicates the existence of the components' interaction in the PVC/CPE blends. The addition of CPE improves the thermal stability of PVC for all the investigated blends in the temperature range where α_calc is greater than α_exp. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 166–172, 2000     

Evaluation of the effects of biobased plasticizers on the thermal and mechanical properties of poly(vinyl chloride)

Blends were prepared of poly(vinyl chloride) (PVC) with four different plasticizers; esters of aconitic, citric, and phthalic acids; and other ingredients used in commercial flexible PVC products. The thermal and mechanical properties of the fresh products and of the products after 6 months of aging were measured. Young's modulus of the PVC blends was reduced about 10‐fold by an increase in the plasticizer level from 15 to 30 phr from the semirigid to the flexible range according to the ASTM classification, but a 40‐phr level was required for PVC to retain its flexibility beyond 6 months. At the 40‐phr level, tributyl aconitate performed better than diisononyl phthalate (DINP) or tributyl citrate, in terms of lowering Young's modulus, both in the fresh materials and those aged for 6 months. The effects of the four plasticizers on the glass‐transition temperature (T_g) were similar, with T_g close to ambient temperature at the 30‐ and 40‐phr levels in freshly prepared samples and at 40–60°C in those aged for 6 months. The thermal stability of the PVC plasticized with DINP was superior among the group. Overall, tributyl aconitate appeared to be a good candidate for use in consumer products where the alleged toxicity of DINP may be an issue. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1366–1373, 2006     

Synthesis and evaluation of dioctyl 2,5-thiophenedicarboxylate as a potentially bio-based plasticizer for poly(vinyl chloride)

In this work, dioctyl 2,5-thiophenedicarboxylate (DOT), a potentially bio-based plasticizer, was synthesized and evaluated as an alternative to traditional petroleum-based plasticizers. The chemical structure of DOT was confirmed by FTIR and ¹H NMR. Besides, its plasticization effect on poly(vinyl chloride) (PVC) was investigated in detail, and dioctyl 2,5-furandicarboxylate (DOF) as well as dioctyl isophthalate (DOIP) with similar chemical structures were used as references. The DMA results showed that the glass transition temperature (T_g) of PVC/DOT, PVC/DOF, and PVC/DOIP was 45.1°C, 33.6°C, and 51.3°C, respectively, indicating that the plasticizing efficiency of DOT was better than that of DOIP but lower than that of DOF. However, the tensile test results exhibited that the elongation at the break of PVC/DOT was higher than that of PVC/DOF, which was attributed to the easy phase separation between DOF and PVC. In addition, DOT displayed the best volatility resistance and exudation resistance among the three plasticizers, attributed to its highest molecular weight. Moreover, the migration loss of DOT in non-polar solvents was much smaller than that of DOIP because of its stronger molecular polarity. In conclusion, DOT has good potential to replace traditional petroleum-based plasticizers and be used as a primary plasticizer for PVC.     

Effect of Polyhedral Oligomeric Silsesquioxanes Nanoparticles on Thermal and Mechanical Properties of Poly(vinyl chloride) Composite Materials

The modification of poly(vinyl chloride) (PVC) by polyhedral silsesquioxane containing both methacryl and octyl groups (MeOctPOSS) was the task of studies. The PVC nanocomposites with MeOctPOSS concentration between 1 and 10 wt% were prepared by melt mixing processing, and the homogeneity of MeOctPOSS dispersion in the polymeric matrix was confirmed by scanning electron microscopy and energy dispersive spectroscopy observations. The influence of MeOctPOSS on glass transition temperature (T_g) determined by means of dynamic mechanical thermal analysis (DMTA) and differential scanning calorimetry (DSC) was observed, whereas, higher the measurement frequency, higher the glass transition temperature was noted. The MeOctPOSS concentration‐dependent PVC glass transition temperature was shifted from 73.8°C to about 68°C (? = 1 Hz) and from 76.5°C to 70.8°C (? = 10 Hz) for increasing additive content. Similar result of decreasing T_g value was observed by DSC method. An introduction of 10 wt% of MeOctPOSS into the PVC matrix results in a visible decrease of the maximum value of loss modulus (G′) of approximately 12% and 18% by 1 Hz and 10 Hz, respectively, as well as in a significant reduction of the static elastic modulus. It was stated that the polyhedral oligomeric silsesquioxanes with both methacryl and octyl groups may act as plasticizers of the PVC matrix. J. VINYL ADDIT. TECHNOL., 25:E48–E54, 2019. © 2018 Society of Plastics Engineers     

Thermal characterization of some products obtained by chemically modified poly(vinyl chloride) with phenol

The chemical modification of poly(vinyl chloride) (PVC) in reaction with phenol, in the absence of a catalyst and at temperatures within the range of 60°C and the boiling temperature of phenol (180°C), led to the reaction products with the general structure of a vinyl chloride–vinyl phenol copolymer. The synthesized polyphenols were thermally characterized using the following experimental techniques: thermo–optical analysis (TOA), thermogravimetry (TG), derivative thermogravimetry (DTG), and pyrolysis in combination with gas chromatography (P–GC). The PVC samples modified with phenol show a thermal stability lower than the original PVC sample. The glass transition temperatures (T_gs) increase with increased degree of chlorine substitution. The main pyrolysis products of the modified PVC samples are hydrocarbons with low boiling points (C₁–C₄), benzene, toluene, naphthalene, indan, and phenol. The semiquantitative estimation of the pyrolysis products of the synthesized samples led to the conclusion that the following structural element types can be present, statistically distributed along the chain: vinyl chloride and vinyl phenol units, acetylenic and ethylenic units, and indan type structures. © 1995 John Wiley & Sons, Inc.     

Recycling of Waste PET: Usage as Secondary Plasticizer for PVC

Postconsumer water bottle poly(ethylene terephthalate) (PET) flakes were depolymerized with ethylene glycol (EG) by the glycolysis reaction in the presence of zinc acetate as the catalyst. In the depolymerization reactions, different weight ratios of PET/EG were used. In order to obtain polyesters used as PVC plasticizers, these glycolysis products containing hydroxyl end groups were reacted with an adipic acid (AA)–containing diacid group at equivalent amounts. In order to obtain PVC plastisols, PVC was dispersed into a plasticizers' mixture composed of di-isooctyl phthalate (DOP) and polyester products by using a high-speed mixer (PVC/plasticizers, 65/35 w/w). For the preparation of plasticizer mixture polyester products were used at a weight ratio of 20%, 40%, 60% of DOP. Plasticized PVC sheets were prepared from plastisols and their glass transition temperatures (T_g), migration, and mechanical properties were determined. The results show that the polyester products obtained from glycolysis products of waste PET can be used as secondary plasticizers, with DOP for PVC.     

Palm oil‐based compound as environmentally friendly plasticizer for poly(vinyl chloride)

Many plasticizers have been invented to serve the purpose of making poly(vinyl chloride) (PVC) into a more flexible plastic. In this work, the potential of palm oil‐based compound (Palm1) as a polymeric plasticizer for PVC was investigated. Plasticization of PVC was conducted via the solvent casting technique, using tetrahydrofuran (THF) as the mutual solvent. Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC) were used to find evidence of interactions between the plasticizer and PVC. Transition temperatures (T_gs) of the plasticized PVC were obtained using DSC, and their thermal stabilities were evaluated using a thermogravimetric analyzer (TGA). Results from the study show that the polymeric plasticizer could interact with PVC chains via polar interaction involving –C‐Cl of PVC and possibly the ‐OH groups of Palm1. T_g of the PVC was reduced after it was plasticized with Palm1. The results obtained from this study suggest that the Palm1 may have the potential to serve as an environmentally friendly plasticizer for PVC. J. VINYL ADDIT. TECHNOL., 22:80–87, 2016. © 2014 Society of Plastics Engineers     

Migration of phthalate and non‐phthalate plasticizers out of plasticized PVC films into air

The aim of the present work is to provide information about the migration of phthalate and non‐phthalate plasticizers generally used in flexible polyvinyl chloride (PVC) applications. Plastisols (pastes) were prepared by mixing PVC, plasticizer, and thermal stabilizer. The plasticized PVC (p‐PVC) films are obtained by gelation at 160°C for 15 min. The p‐PVC films were heat treated at 50, 85, 100, 130, and 160°C up to 420 min to follow the mass loss to find out diffusivity of plasticizer out of films into air and to determine related activation energies. The films having di‐octyl terephthalate (DOTP) and di‐isononyl 1,2‐cyclohexanedicarboxylic acid (DINCH) exhibited the lowest mass loss in general, among the phthalate and non‐phthalate plasticizer having p‐PVC films, respectively, as confirmed by FTIR investigation. The same tendency was observed for diffusion coefficients and for the activation energies of migration. The diffusion coefficients were found to be around 3.5 × 10^?18–2.1 × 10^?17 m²/sec for the studied plasticizers in PVC at 50°C and around 4.0 × 10^?15–9.9 × 10^?14 m²/sec at 160°C. The activation energies for 85–160°C interval were determined to be between 70 and 153 kJ/mol (0.72–1.58 eV) for the plasticizers used herein those could be treated as a homologous series as deduced from the related compensation factors. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Alloying of poly(vinyl chloride) to reduce plasticizer migration

Concern over the migration of low molecular weight plasticizer from flexible poly(vinyl chloride) (PVC) used in toys and medical products has spearheaded the commercialization of a number of plasticizing polymers. In this study the plasticizing behavior of an ethylene/vinyl acetate/carbon monoxide terpolymer (Elvaloy® from DuPont) was investigated. Blends of PVC, Elvaloy 742, and dioctyl phthalate (DOP) were processed on a twin‐roll mill and compression molded into plaques. These materials were characterized in terms of their hardness, glass‐transition temperature (T_g), clarity, mechanical properties, and plasticizer migration behavior. The ratios of PVC/DOP/Elvaloy investigated were determined by experimental design. Using this approach it was possible to model the results and produce contour plots to map out the properties of a wide range of formulations. It was confirmed that Elvaloy 742 is compatible with PVC and has a plasticizing effect: this was demonstrated both in terms of a reduction in Shore A hardness and a reduction in T_g. Plasticizer migration was reduced in proportion to the amount of liquid plasticizer replaced. Plasticizing with Elvaloy gave an improvement in tear strength. However, at constant hardness there was no improvement in tensile strength from replacing DOP with Elvaloy. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2022–2031, 2004     

Phase segregation behavior in PE/DOP blends and glass‐transition temperatures of polyethylene

Phase segregation behavior in PEs/DOP blends, interactions between PEs and DOP, and glass‐relaxation transitions of PEs were investigated. FTIR, DSC, and TGA data demonstrated that molecular interactions were present between PEs and DOP. DMA data demonstrated that pure PEs each (except HDPE) exhibited two loss maxima at about ?20 and ?120°C but the PEs/DOP blends (including the HDPE/DOP blend) yielded one new loss maximum at about ?60°C. The glass‐relaxation transitions corresponding to the three loss maxima on the DMA curves were designated α (?20°C), β (?60°C), and γ (?120°C) transitions and were attributed to the relaxation of the amorphous phases in the interlamellar, interfibrillar, and interspherulitic regions, respectively, based on DMA, WAXD, SAXS, and POM measurements. The controversial T_g values of PEs and their origin were thus clarified in this study. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3591–3601, 2001