Free volume holes diffusion to describe physical aging in poly(mehtyl methacrylate)/silica nanocomposites.

نویسندگان

  • Daniele Cangialosi
  • Virginie M Boucher
  • A Alegría
  • J Colmenero
چکیده

The spontaneous thermodynamically driven densification, the so-called physical aging, of glassy poly(mehtyl methacrylate) (PMMA) and its nanocomposites with silica has been described by means of the free volume holes diffusion model. This mechanism is able to account for the partial decoupling between physical aging and segmental dynamics of PMMA in nancomposites. The former has been found to be accelerated in PMMA/silica nanocomposites in comparison to "bulk" PMMA, whereas no difference between the segmental dynamics of bulk PMMA and that of the same polymer in nanocomposites has been observed. Thus, the rate of physical aging also depends on the amount of interface polymer/nanoparticles, where free volume holes disappear after diffusing through the polymer matrix. The free volume holes diffusion model is able to nicely capture the phenomenology of the physical aging process with a structure dependent diffusion coefficient.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Denture base polymers, poly methyl methacrylate improved using free radical copolymerization

Poly methyl methacrylate (PMMA) is the most common material used in Prosthodontics. Several studies indicate a breakdown of the number of very high resin bases after 2 to 3 years to avoid breaking bass and several attempts have been made, such as altering the chemical structure of resin by adding causes cross linking or copolymerization. The innovative method for improving the physical properti...

متن کامل

Abstract Submitted for the MAR13 Meeting of The American Physical Society The investigation of the viscoelastic properties of silica/PMMA nanocomposites as a function of silica surface chemistry1

Submitted for the MAR13 Meeting of The American Physical Society The investigation of the viscoelastic properties of silica/PMMA nanocomposites as a function of silica surface chemistry1 HEATHER CONWAY, DENIZ RENDE, RAHMI OZISIK, Rensselaer Polytechnic Institute — Poly(methyl methacrylate), PMMA, has been used as an economic alternative to glass and polycarbonate in differing situations because...

متن کامل

Study of Non-Isothermal Crystallization Kinetics of Biodegradable Poly(ethylene adipate)/SiO2 Nanocomposites

Poly(ethylene adipte) and poly(ethylene adipate)/silica nanocomposite (PEAd/SiO2) containing 3 wt. % SiO2  were prepared by an in situ method. The examinations on the non-isothermal crystallization kinetic behavior have been conducted by means of differential scanning calorimeter (DSC). The Avrami, Ozawa, and combined Avrami and Ozawa equations were applied to describe the crystallization kinet...

متن کامل

Dynamics in Polymer Nanocomposites

Polymer diffusion and matrix morphology are investigated in polymer nanocomposites (PNCs). Using elastic recoil detection, tracer diffusion coefficients (D) of dPS and dPMMA are measured in PNCs containing polystyrene (PS) with phenyl-capped (Ph) silica, and poly(methyl methacrylate) (PMMA) with hydroxylterminated (OH) silica nanoparticles (NPs), respectively. As NP volume fraction increases or...

متن کامل

Synthesis and Examination of Nanocomposites Based on Poly(2-hydroxyethyl methacrylate) for Medicinal Use

Preparation of poly(2-hydroxyethyl methacrylate) (PHEMA) based nanocomposites using different approaches such as synthesis with water as the porogen, filling of polymer matrix by silica and formation of interpenetrating polymer networks with polyurethane was demonstrated. Incorporation of various biologically active compounds (BAC) such as metronidazole, decamethoxin, zinc sulphate, silver nitr...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • The Journal of chemical physics

دوره 135 1  شماره 

صفحات  -

تاریخ انتشار 2011