TIT# Dynamic Mechanical Behavior and Nanostructure Morphology of
     Hyperbranched-modified Polypropylene Blends
AUT# Ganjaee Sari, Morteza; Stribeck, Norbert; Moradian, Siamak; Zeinolebadi, Ahmad;
     Bastani, Saeed; Botta, Stephan; Bakhshandeh, Ehsan;
SOU# Polym. Int. (2014), 63(2), 195-205
LOC# xv143
CLA#
COM# DOI 10.1002/pi.448
APP#
MAT#
ABS# Polypropylene (PP) is modified utilizing two types of
     polyesteramide-based hyperbranched polymers (amphiphilic PS & hydrophilic
     PH). A maleic anhydride-modified PP (PM) used as a reactive dispersing
     agent to enhance the modification by grafting the hyperbranched polymers
     onto the PP chains. Pure polypropylene, two different non-reactively
     modified samples, i.e. excluding PM, and two different reactively
     modified samples, i.e. including PM, are studied. Investigating the
     morphology of the samples is performed by scanning electron microscope,
     SEM. To follow the effect of the modification on the dynamic mechanical
     properties, dynamic mechanical analysis (DMA) experiments both in melt
     (rheomertics mechanical spectrometry, RMS) and solid state (dynamic
     mechanical thermal analysis, DMTA) are carried out. In the next step, the
     nano-crystalline structure of the samples is studied by small angle
     X-ray scattering (SAXS) in two different modes, i.e. static and
     recrystallization. Hundreds of SAXS patterns are analyzed automatically
     using procedures written in PV-WAVE image processing software. The chord
     distribution function, CDF, is calculated and the long period (lp) of the
     crystal lamellae is extracted from the CDFs. RMS results show both
     hyperbranched polymers decrease complex viscosity, $/eta^*$, and enhance
     liquid-like behavior. This happens more significantly when PM is included.
     DMTA results reveal Tg decreases when PS and PH are added. In the
     reactively modified samples this reduction compensate most probably
     because of the cross-linked structure formed through the grafting
     reaction between hyperbranched polymers and PM. Such structure is
     confirmed by SAXS data and respective calculated CDFs in
     recrystallization mode. Static SAXS data also show enhancement in
     crosshatched morphology of the crystalline lamellae of PP for reactively
     modified samples compared to non-reactively modified samples.