Rheological and mechanical properties of PVC/CaCO3 nanocomposites prepared by in situ polymerization

Xiao Lin Xie, Qing Xi Liu, Robert Kwok Yiu Li, Xing Ping Zhou, Qing Xin Zhang, Zhong Zhen Yu, Yiu Wing Mai

Research output: Journal article publicationJournal articleAcademic researchpeer-review

346 Citations (Scopus)

Abstract

Poly(vinyl chloride) (PVC)/calcium carbonate (CaCO3) nanocomposites were synthesized by in situ polymerization of vinyl chloride (VC) in the presence of CaCO3 nanoparticles. Their thermal, rheological and mechanical properties were evaluated by dynamic mechanical analysis (DMA), thermogravimetry analysis (TGA), capillary rheometry, tensile and impact fracture tests. The results showed that CaCO3 nanoparticles were uniformly distributed in the PVC matrix during in situ polymerization of VC with 5.0 wt% or less nanoparticles. The glass transition and thermal decomposition temperatures of PVC phase in PVC/CaCO3 nanocomposites are shifted toward higher temperatures by the restriction of CaCO3 nanoparticles on the segmental and long-range chain mobility of the PVC phase. The nanocomposites showed shear thinning and power law behaviors. The 'ball bearing' effect of the spherical nanoparticles decreased the apparent viscosity of the PVC/CaCO3 nanocomposite melts, and the viscosity sensitivity on shear rate of the PVC/CaCO3 nanocomposite is higher than that of pristine PVC. Moreover, CaCO3 nanoparticles stiffen and toughen PVC simultaneously, and optimal properties were achieved at 5 wt% of CaCO 3 nanoparticles in Young's modulus, tensile yield strength, elongation at break and Charpy notched impact energy. Detailed examinations of micro-failure micromechanisms of impact and tensile specimens showed that the CaCO3 nanoparticles acted as stress raisers leading to debonding/voiding and deformation of the matrix material around the nanoparticles. These mechanisms also lead to impact toughening of the nanocomposites.

Original languageEnglish
Pages (from-to)6665-6673
Number of pages9
JournalPolymer
Volume45
Issue number19
DOIs
Publication statusPublished - 3 Sept 2004
Externally publishedYes

Keywords

  • Calcium carbonate
  • In situ polymerization
  • Poly(vinyl chloride)

ASJC Scopus subject areas

  • Organic Chemistry
  • Polymers and Plastics
  • Materials Chemistry

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