Antiplasticization in the Slightly Plasticized Poly(vinyl chloride)

Abstract

The dynamic mechanical moduli of slightly (0-16 wt96) plasticized poly(vinyl chloride) were measured by the method of free damped oscillation in the temperature range from -180 to + 100°C. The added plasticizers are tricresyl phosphate (TCP), butyl benzyl phthalate (BBP), dioctyl phthalate (DOP), dibutyl sebacate (DBS) and dioctyl sebacate (DOS). Two dispersion regions (a and /3) are observed in the case of poly(vinyl chloride) and they are influenced by addition of plasticizers. The a-dispersion shifts to the lower temperature side and broadens with increasing plasticizer content. These effects are mainly dependent upon the plasticizer species, and of the above plasticizers their plasticizing ability decreases in the order of DOS> DBS>DOP>BBP>TCP. The /3-dispersion, whose activation energy was estimated to be 14.3 kcal/mo!, first begins to disappear from the higher temperature side with increasing plasticizer content and ultimately vanishes. This effect scarcely depends upon the plasticizer species.Young's moduli of these samples were measured at -20-+40°C from observing the tensile stress relaxation. The modulus vs. plasticizer content curve shows a maximum. This is an example of "antiplasticization." The ability of additives to provoke antiplasticization decreases in the reverse order of plasticizing ability, that is, in the order of TCP>BBP>DOP>DBS>DOS.KEY WORDS Antiplasticization / Poly(vinyl chloride)/ Plasticizer/ Viscoelasticity / Polymer

Thermally stimulated creep spectroscopy for the study of DGEBA-DDM networks

“…2), while the evolution of its peak temperature seems to indicate greater mobility for the hydroxyether segments. This apparently paradoxical behaviour is similar to the so-called 'antiplasticizing effect' observed in the anomalous plasticization of some linear polymers, e. g. PVC, if low quantities of compounds with low molecular weight are added to the polymer [10,11]. For the materials under study, the depression of the fl-mode could be due to the unreacted epoxy groups, acting as anti-plasticizers, that would build up hydrogen bonds with the relaxing units and block the fl-motions.…”

X-ray study of microstructure of slightly plasticized poly-(vinylchloride) (PVC)

“…In our opinion, the experimentally observed strong interaction between Ca-stearate molecules and PVC chains in the samples examined acts as a crosslinking agent in the system with up to 8-10 % plasticizer content; by increasing this content and presumably between 15 and 30 % of DOP, the interaction Ca-stearate -PVC becomes weaker, the molecular motion of the polymer increases and the relaxation mechanism of the a-dispersion [13] becomes directly related to the addition of the plasticizer.…”

“…Several authors studied the phenomenon of PVC stiffening by some plasticizers in a small range of their concentration [13,14] called antiplasticization. Makaruk and Retko [14] assumed that the changes of mechanical properties termed as antiplasticization can be interpreted as a result of crosslinking between the macromolecules and the molecules of plasticizer.…”

Plasticized PVC reinforced with cellulose whiskers. I. Linear viscoelastic behavior analyzed through the quasi-point defect theory

“…The relaxation intensity is lower than for pure PVC, as expected when using DOP as the plasticizer. 22 The Cole-Cole diagram shows an evolution of the materials during measurements above 170 K as observed for PVC 23 (cf. Fig.…”