Study of discolouring change in PVC, plasticizer and plasticized PVC films

Hollande, Stéphanie; Laurent, Jean-Louis

doi:10.1016/s0141-3910(96)00165-6

Cited by 63 publications

(36 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Bacterial growth might be inhibited by desiccation, solar irradiation, or in situ acidification of the pPVC following photochemical or thermal degradation (25,30). Acidification of the pPVC could inhibit bacterial growth, as fungi tolerate lower pHs than do bacteria.…”

Section: Alternaria Alternatamentioning

confidence: 99%

Fungal Colonization and Biodeterioration of Plasticized Polyvinyl Chloride

Webb

Nixon

Eastwood

et al. 2000

Appl Environ Microbiol

174

100

View full text Add to dashboard Cite

Significant substratum damage can occur when plasticized PVC (pPVC) is colonized by microorganisms. We investigated microbial colonization of pPVC in an in situ, longitudinal study. Pieces of pPVC containing the plasticizers dioctyl phthalate and dioctyl adipate (DOA) were exposed to the atmosphere for up to 2 years. Fungal and bacterial populations were quantified, and colonizing fungi were identified by rRNA gene sequencing and morphological characteristics. Aureobasidium pullulans was the principal colonizing fungus, establishing itself on the pPVC between 25 and 40 weeks of exposure. A group of yeasts and yeast-like fungi, including Rhodotorula aurantiaca and Kluyveromyces spp., established themselves on the pPVC much later (after 80 weeks of exposure). Numerically, these organisms dominated A. pullulans after 95 weeks, with a mean viable count ؎ standard error of 1,000 ؎ 200 yeast CFU cm ؊2 , compared to 390 ؎ 50 A. pullulans CFU cm ؊2 . No bacterial colonization was observed. We also used in vitro tests to characterize the deteriogenic properties of fungi isolated from the pPVC. All strains of A. pullulans tested could grow with the intact pPVC formulation as the sole source of carbon, degrade the plasticizer DOA, produce extracellular esterase, and cause weight loss of the substratum during growth in vitro. In contrast, several yeast isolates could not grow on pPVC or degrade DOA. These results suggest that microbial succession may occur during the colonization of pPVC and that A. pullulans is critical to the establishment of a microbial community on pPVC.Plasticized PVC (pPVC) is highly susceptible to microbial attack in many different environmental situations. The problem was first identified in U.S. government reports of the deterioration of military equipment (8, 44), and subsequent reports described defacement and deterioration of commercial pPVC products (20,50). Biodeterioration of pPVC is now known to occur in a wide range of industrial, commercial, and structural applications (18,19,22).The susceptibility of pPVC results from the presence of plasticizers, commonly organic acid esters such as dioctyl phthalate (DOP) and dioctyl adipate (DOA), added to modify physical or mechanical properties of the polymer. Both bacteria (6,7,14) and fungi (5, 36) can degrade ester-based plasticizers. Loss of plasticizers from pPVC due to microbial degradation results in brittleness, shrinkage, and ultimately failure of the pPVC in its intended application.Microbial deterioration of pPVC has been studied extensively in vitro. Many studies have examined the resistance of pPVC formulations incorporating biocides to colonization by test organisms (38,39,46). Other research has determined biodegradability by measuring changes in the physical properties of pPVC, such as changes in tensile strength (49), mass (9), or electrical properties (42) during biodegradation. Several international standard test methods for microbiological susceptibility of plastics have been established (1, 2, 26).Colonization processes occurring...

show abstract

Section: Alternaria Alternatamentioning

confidence: 99%

Fungal Colonization and Biodeterioration of Plasticized Polyvinyl Chloride

Webb

Nixon

Eastwood

et al. 2000

Appl Environ Microbiol

174

100

View full text Add to dashboard Cite

show abstract

“…The major disadvantage of PVC is its thermal instability. The main reaction of the PVC thermal degradation is dehydrochlorination (DHC), which starts at about 100°C and is the reason for discoloration, due to the formation of polyene sequences [1,6,7]. It is catalyzed by HCl evolved (autocatalysis), and also promoted by other strong acids.…”

Section: Introductionmentioning

confidence: 99%

Synergistic effect of metal soaps and natural zeolite on poly(vinyl chloride) thermal stability

Atakul¹,

Balköse²,

Ülkü³

2005

J Vinyl Addit Technol

View full text Add to dashboard Cite

The synergistic effect of metal soaps (zinc stearate and calcium stearate) and/or natural zeolite (clinoptilolite) on PVC thermal stability was investigated. For this purpose, PVC plastisol was prepared by mixing poly(vinyl chloride) (PVC) and dioctyl phthalate (DOP) and stabilized with different amounts of metal soaps and zeolite. Kinetic studies of dehydrochlorination at 140 and 160°C were done for unstabilized and stabilized PVC plastigels using 763 PVC Thermomat equipment. The stabilizing effect of zeolite on the increase in the induction period of the sample was considered to result from the absorption of HCl, a property that was thought to reduce the autocatalytic effect of HCl evolved at the initial stages of dehydrochlorination. Since the induction time of the sample having 0.53% of zinc stearate and 0.53% of zeolite was higher than those of the PVC plastigels having only zinc stearate or zeolite, the synergistic effect on thermal stability was observed at low levels of these additives.

show abstract

“…PVC, a known thermal and photo unstable polymer, degrades over 130ºC (Pospisil et al, 1999;Veronelli et al, 1999). The photo and thermal degradation releases hydrochloric gas (dehydrochlorination) that leads to the formation of conjugate polyene sequences (-CH=CH) in the polymer chains, giving the PVC a reddish brown color (Hollande and Laurent, 1997;Veronelli et al, 1999). The polymer surface deterioration is an interfacial process.…”

Section: Introductionmentioning

confidence: 99%