Thermal stability of epoxidized soybean oil and its absorption and migration in poly(vinylchloride)

Abstract

Thermal analyses of epoxidized soybean oil (ESO) were conducted and showed that it was stable up to temperatures as high as 240–260°C in air‐free environment. The solubility and transport characteristics of ESO in poly(vinylchloride) (PVC) were also investigated under various conditions. The absorption study showed that the resin had a void volume of ∼0.3 cm3/g. Furthermore, ESO was found to be sufficiently soluble in the PVC matrix to function as an effective plasticizer, with equilibrium solubility of 72 g/100 g PVC at 80°C and 163 g/100 g PVC at 120°C. The absorption of ESO in PVC grains was a three step process comprising “induction,” “swelling,” and “saturation” periods. Torque rheometer studies showed that higher mixer temperature and/or speed facilitated uptake of plasticizer in PVC and ultimate fusion. Migration studies of plasticized and stabilized PVC compositions showed no change in mass at 40°C, but increasingly greater mass loss as the temperature was raised up to 120°C. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers

Bis(2-ethylhexyl) succinate in mixtures with epoxidized soybean oil as bio-based plasticizers for poly(vinylchloride)

“…These findings indicate that, in addition to molecular weights of the plasticizers, their functional groups also influenced the rate of uptake in the polymer. Assuming a plasticizer density of approximately 1 g/cm 3 , about 30 phr plasticizer would have been held in the pores of the PVC as the grade of PVC used in this study had porosity of 0.3 cm 3 /g . However, as the actual amounts of plasticizers imbibed ranged from 50 to 83 phr, it is reasonable to surmise that the remaining quantities would have been absorbed in the polymer matrix.…”

“…Absorption of the various plasticizers in the PVC compositions at a set temperature of 90°C, which was above the 83°C glass transition temperature of the resin , was completed within 5 min (at most). The rate of absorption of the petroleum‐derived plasticizers was dependent on their molecular weights; TOTM was the slowest to absorb (4 min at 50 phr), DOP was the fastest to absorb (2 min at 50 phr; 3 min at 83 phr), and DIDP fared in‐between (3 min at 50 phr).…”

“…The polymer used was OxyVinyls 240F suspension‐grade PVC homopolymer powder . The other materials used were Satintone SP‐33 calcined kaolin clay (as electrical insulation filler); Baeropan MC 90249 KA or Baeropan MC 9754 KA calcium‐zinc mixed metal soaps (as primary heat stabilizers); Irganox 1076 (as antioxidant); Microfine AO9 antimony trioxide (as flame‐retardant synergist); bis(2‐ethylhexyl) succinate (also known as dioctyl succinate, DOS, as plasticizer or coplasticizer; derived from bio‐succinic acid; obtained from Myriant Technologies, LLC; molecular weight: 343 g/mol); Plas‐Chek 775 ESO (as plasticizer or coplasticizer; molecular weight: ca.…”

“…The effectiveness of succinate esters as PVC plasticizers varies considerably, depending on the lengths of the alkoxy chains . Additionally, epoxidized derivatives of vegetable oils constitute another readily available class of bioplasticizers . An example of the latter family of plasticizers is epoxidized soybean oil (ESO).…”

Thermal and mechanical properties of bio-based plasticizers mixtures on poly (vinyl chloride)

“…The samples are colored because of the dehydrochlorination and formation of conjugated double bonds in PVC sheets. During dehydrochlorination, HCl molecules are extracted, which initiates the formation of double bonds and polyenes in PVC chains and noticeable color change from yellow to black, when the conjugated polyene sequences contain more than four to five double bonds [25] . Figure 2 shows the discoloration degree of sheets containing different mixtures of plasticizers.…”