Gas chromatographic studies on the compatibility of PVC with a migration resistant plasticizer

Abstract

The technique of inverse gas chromatography (IGC) was used to investigate the thermodynamic miscibility (compatibility) of low molecular weight PVC-poly(adipate ester) plasticizer mixtures. The polymer-plasticizer thermodynamic interaction parameters were determined from chromatographic retention data for various low molecular weight volatile solutes (probes) on stationary phase mixtures which covered the entire composition range for each component. Experiments were carried out in the temperature range of 90 to 110 "C. The Flory-Huggins interaction parameter (1s) values were found to be dependent on the chemical nature of the probes, the temperature, and the composition of the mixed phase. The results predict a relatively high polymerplasticizer compatibility for a wide range of polymer-plasticizer mixtures (up to approx. 70 wt.-Vo of plasticizer). Results were also compared to our own previous data using high molecular weight PVC. ZUSAMMENFASSUNGDie Technik der inversen Gaschromatographie (IGC) wurde zur Untersuchung der thermodynamischen Mischbarkeit (Vertraglichkeit) von niedermolekularem Poly(vinylchlorid) (PVC) mit einem Poly(adipinsaureester) als Weichmacher angewendet. Die thermodynamischen Polymer-Weichmacher-Wechselwirkungsparameter wurden aus den chromatographischen Retentionsdaten verschiedener, niedermolekularer fliichtiger Substanzen als mobile Phase auf einer stationaren Phase aus Polymer-Weichmacher-Mischungen, die sich iiber den gesamten mdglichen Zusammensetzungsbereich erstreckten, ermittelt. Die Untersuchungen wurden im Temperaturbereich von 90 bis 1 10 "C durchgefiihrt. Der Flory-Huggins-Wechselwirkungsparameter (x&) hangt dabei im wesentlichen von der chemischen Natur der als "Sonde" verwendeten fliichtigen Substanz (mobile Phase), von der lkmperatur und von der Zusammensetzung der Polymer-Weichmacher-Mischung (station&e Phase) ab. Die Ergebnisse deuten auf eine relativ gute Polymer-Weichmacher-Vertraglichkeit iiber einen weiten Zusammensetzungsbereich (bis ca. 70 Gew.-Yo Weichmacher) hin; die Vertraglichkeit ist damit besser als bei friiheren Untersuchungen mit hochmolekularem PVC.

Concentration dependency of interaction parameter between PVC and plasticizers using inverse gas chromatography

“…At the high PVC end of composition, the values of 23 Ј decreased from positive values to negative. A similar dependency on 23 Ј in the PVC/dioctyl phthalate system was reported by Su et al 11 The values of 23 Ј at a PVC/ plasticizer ratio of 92/8 were also reported for different temperatures by Demertzis et al 31,32 The values of 23 Ј increased as temperature increased, suggesting that the system became less thermodynamically compatible. A similar temperature dependency was also observed in the results of a study by Su et al 11 The values of retention volumes and interaction parameters between probes and PVC, 12 , and probes and plasticizer, 13 , reported by Demertzis et al 31,32 were used to calculate solubility parameters of PVC and plasticizers.…”

“…The more negative value obtained by Woo et al can be explained by the lower temperature (Ͻ80°C) of measurement. As pointed out earlier, the 23 values of PVC/plasticizers 11,31,32 showed an increasing trend when temperature increased. In the study of Woo and coworkers, 43 cloud points and lower critical solution temperatures were also observed between 140 and 180°C for polyesters with a CH 2 /COO ratio between 11 and 14, indicating that 23 became more positive when temperature increased.…”

“…Specific retention volumes at 100°C were reported together with probepolymer interaction parameters at 90, 100, 110, and 120°C. In another study, 32 the same authors determined the retention volume using a PVC with molecular weight of about 90,000 and an epoxidized soybean oil (ESO). The ESO contained approximately 4.5 oxirane rings in its structure.…”

Synthesis and application of a novel cardanol‐based plasticizer as secondary or main plasticizer for poly(vinyl chloride)

“…Moreover, petroleum shortages have encouraged research on chemical products obtained from renewable resources. As a result, there is growing interest in the use of natural‐based renewable plasticizers that have low toxicity for the replacement of petroleum‐based plasticizers . Hence, it is important to explore renewable plasticizers having good flame retardancy and thermal stability.…”

Structural expressions of long-chain esters on their plasticizing behavior in poly(vinyl chloride)

“…13 The polymer-plasticizer interaction can be evaluated by various methods, including studies of the diffusion of plasticizers in polymer^.^^-^^ Commonly the glass transition temperature (T,) of polymers is measured:' which is lowered in the presence of plasticizers. 0024-929719212225-6765$03.00/0…”