Click for new scientific resources and news about Corona[COVID-19]

Paper Information

Journal:   IRANIAN JOURNAL OF POLYMER SCIENCE AND TECHNOLOGY (PERSIAN)   FEBRUARY-MARCH 2013 , Volume 25 , Number 6 (ISSUE NO. 122); Page(s) 468 To 475.
 
Paper: 

SYNTHESIS AND CHARACTERIZATION OF LOW DENSITY PMMA-BASED MICROBALLOONS

 
 
Author(s):  BEIGI BOROUJENY SAEED, ATAEI MOHAMMAD*, NODEHI AZIZOLAH, FERDOWSI MOHAMMAD, NOSRATZADEGAN KEYVAN
 
* IRAN POLYMER AND PETROCHEMICAL INSTITUTE, TEHRAN, IRAN
 
Abstract: 

Hollow microspheres or microballoons are gas-filled spherical particles with diameters between 1 to 1000 micrometers. The wall material may be made from glass, ceramic oxides, polymers or even metals. The typical thickness of the wall is in the range of 1 to 10% of the outer diameter of the sphere. Hollow microspheres have low density and high specific surface. They are widely used as toners, immobilization carriers, chromatographic packings, and sound dampening or adsorption materials. Thermally expandable microspheres are hollow balloons that consist of a thermoplastic shell with a liquid blowing agent as the core. These microspheres are expanded by applying temperatures higher than the glass transition temperature of the thermoplastic shell. The particles expand due to the evaporation of the encapsulated solvent which causes an internal pressure. In this study the primary expandable particles were synthesized via suspension polymerization of methacrylate monomers in the presence of pentane as a blowing agent and benzoyl peroxide as a thermal initiator. In the second step, the particles consisting of PMMA shell and pentane core were expanded at elevated temperature to obtain microballoons with a very low density. Morphology of the particles was studied using scanning electron microscopy. The results showed that the process successfully resulted in formation of spherical microballoons. The mean diameter of unexpanded particles was about 30 mm and thickness of the shell was about 2 mm while, their mean diameter after expansion was about 90 mm and the thickness of the shell decreased to 400 nm. The diameter to wall thickness ratio of expanded particles was about 1: 200 which provided particles with a very low density of 0.05 g/cm3.

 
Keyword(s): MICROBALLOONS, SUSPENSION POLYMERIZATION, BLOWING AGENT, EXPANDABLE MICROSPHERES, PMMA
 
References: 
  • ندارد
 
  Persian Abstract Yearly Visit 82
 
Latest on Blog
Enter SID Blog