This document describes a study on the thermal decomposition of polyvinyl chloride (PVC) foams prepared with different commercial plasticizers. Twenty PVC plastisols were prepared using a PVC-vinyl acetate copolymer resin and one of 20 plasticizers. The foams were analyzed using thermogravimetric analysis. Up to four weight loss steps were observed, corresponding to plasticizer evolution, PVC dehydrochlorination, and carbonization of decomposition residues. Plasticizers with lower molecular weights caused decomposition of the plasticized PVC resin at lower temperatures than pure PVC resin. The type and molecular weight of the plasticizer influenced its effect on destabilizing the thermal decomposition of the resin.

1. Thermal Decomposition of PVC Plastisol Foams.
Influence of the type of plasticizer
A. Marcilla, A. Zoller and M.I. Beltrán
Department of Chemical Engineering, University of Alicante
P.O.Box 99. E-03080 Alicante, Spain
*Corresponding author: e-mail:antonio.marcilla@ua.es, tel.:+349653400-3365
REFERENCES:
1. Zoller, A. and Marcilla A., Soft PVC foams. Study of the gelation, fusion and foaming processes.
Part I.:Phthalate ester plasticizers,Journal of Applied Polymer Science, 121,3 (2011) 1495-1505.
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Part II.:Adipate, Citrate and Other Type of plasticizers,Journal of Applied Polymer Science, In Press (2011)
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CONCLUSIONS:
ABSTRACT:
Thermal decomposition of flexible PVC foams prepared with 20 commercial
plasticizers has been studied1,2. It has been observed, that the plasticized PVC resin
decomposes at lower temperatures, than the pure PVC-VA resin. Moreover, the
thermograms show up to 4 weight loss steps3,4.
It has been found that the lower the molecular weight of the plasticizer the lower the
temperature of the first decomposition process of the resin, consequently the more
compatible plasticizers show a destabilizing effect on the resin decomposition.
AzodicarbonamideUnicell D 200 AFoaming
Agent
Zinc-oxideZnOCatalyst
Epoxidized Soybean OilLankroflex 2307Co-stabilizer
Ca / Zn stabilizerReagens CL 4Stabilizer
DescriptionDescriptionCommercialCommercial NameNameAdditivesAdditives
vinyl chloride-vinyl acetate copolymer
with a 4.8 % of vinyl acetate, and a K
value of 70, generally applied to prepare
plastisols of medium viscosity.
Etinox 400E 400
DescriptionCommercial NameResin
MEASUREMENT CONDITIONS:
• Approximately 6 mg of sample
• TGA in a nitrogen atmosphere (50 mL/min)
• heating rates of 5 K/min from room temperature to 873 K
• Termobalance METTLER TOLEDO, model TGA/SDTA851e/SF/1100
• continuous on-line records of weight loss and temperature
• TGA and DTG curves
RESULTS:
MATERIALS:
METHOD OF SAMPLE PREPARATION:
Twenty PVC plastisols were prepared by mixing
• 100 phr (parts per hundred resin) of the ETINOX 400 PVC resin
• 2 phr of Reagens CL4 commercial Zn/Ca-stearate stabilizer
• 6 phr of Lankroflex 2307 epoxidized soybean oil co-stabilizer
• 100 phr of one of the studied plasticzers (see Table)
• 2 phr of zinc oxide kicker/catalyst
After mixing, the pastes were subjected to a degassing process for 15
min with a maximum vacuum of 1 mbar for air removal.
These plastisols were cured in an open mould at 180ºC during 10 min.
DTG of the foams obtained from plastisols prepared with linear and branched phthalate
ester plasticizers
BAYER1.055368MESAMOLL
HÉRCULES1.000750H 707
HÉRCULES1.000604H 600
EASTMAN0.984391EASTMAN
BASF0.949425DINCH
MORFLEX1.050486ATHC
MORFLEX1.050402ATBC
BASF1.0503300PM 652
BASF1.1457000PM 632
BASF0.922398DNA
BASF0.935314DHA
EXXON0.991362DIHP
BASF1.039278DIBP
BASF0.983391DOP
PHANCORP0.966447DIDP
BASF0.973421DINP
BASF1.118222DEP
BASF0.953475DUP
BASF0.958450NUP
BASF0.971418HNUP
ProviderDensity
(g/cm3)
Mw
(g/mol)
Acronym
Plasticizers:
-0,002
-0,0015
-0,001
-0,0005
0
50 100 150 200 250 300 350 400 450 500 550
Temperature (ºC)
DerivedWeightLoss(dm/dt)(1/s)
DEP
HNUP
NUP
DUP
DTG of the foams obtained from plastisols prepared with adipate + citrate and other types of
plasticizers
-0,003
-0,0025
-0,002
-0,0015
-0,001
-0,0005
0
50 100 150 200 250 300 350 400 450 500 550
Temperature (ºC)
DerivedWeightLoss(dm/dt)(1/s)
DIBP
DIHP
DOP
DINP
DIDP
-0,002
-0,0015
-0,001
-0,0005
0
50 100 150 200 250 300 350 400 450 500 550
Temperature (ºC)
DerivedWeightLoss(dm/dt)(1/s)
ATBC
ATHC
DHA
DINA
PM 652
PM 632
-0,002
-0,0015
-0,001
-0,0005
0
50 100 150 200 250 300 350 400 450 500 550
Temperature (ºC)
DerivedWeightLoss(dm/dt)(1/s)
ASE
EHBDC
DINCH
H600
H707
The thermograms obtained clearly show the presence of up to four weight
loss steps3,4. The first one corresponds to the evolution of the plasticizer in
clear correlation with its corresponding boiling point5. The rest are related with
the dehydrochlorination and loss of acetic acid3-6 of the copolymer resin and
the products of decomposition of the stabilizer and co-stabilizer, and the last
one, at temperatures higher than 400 ºC corresponding to the carbonization
of the residue of this first step3,4. It can be observed that the lower the
molecular weight of the plasticizer the lower the temperature of the first
decomposition process of the resin.
Pure Etinox 400 resin Pure Etinox 400 resin
Pure Etinox 400 resin Pure Etinox 400 resin
•Plasticized PVC resin decomposes at lower temperatures, than the pure PVC-VA resin
•Up to 4 weight loss steps can be observed. The sharpest peak can be ascribed to the ZnO/ZnCl2 catalyzed
Resin decomposition6, and can be observed in all samples.
•The final peak corresponds to the decomposition of the residue from the first decomposition of the resin
(i.e.: the loss of HCl and HAc) 3-6, and is highly reduced by almost all plasticizers as compared to that
Expected from the resin. DEP and evolves very early in the TG experiment and produces also the largest
destabilization effect7 on the resin.
•Depending on the molecular weight the plasticizers evolve before or after the resin showing a different
destabilization effect. NUP seems not to modify the thermal behavior of the resin (figure 1).
•In the series of the branched phthalates (figure 2) the destabilization effect is highly correlated with the Mw
of the plasticizer except for the DIDP (the DOP is not an isophthalate).
•The citrates and adipates behave in a similar way provoking a destabilization of the resin (figure 3).
•The polymeric adipates show the decomposition of the plasticizer at temperatures above the first
decomposition of the resin.
•The rest of plasticizers show similar effects and again the polymeric ones show the peaks corresponding to
plasticizer between those corresponding to the resin (figure 4).