Search Results

You are looking at 1 - 6 of 6 items for :

  • "α-Nucleating agent" x
  • All content x
Clear All

Abstract  

In this study, α-phase nucleating agent (NA) 1,3:2,4-bis(3,4-dimethylbenzylidene) sorbitol (DMDBS), β-phase rare earth NA (WBG), and their compound NAs were introduced into isotactic polypropylene (iPP) matrix, respectively. Crystallization kinetics and subsequent melting behavior of the nucleated iPPs were comparatively studied by differential scanning calorimetry (DSC) under both isothermal and nonisothermal conditions. For the isothermal crystallization process, it is found that the Avrami model successfully described the crystallization kinetics. The active energy of nonisothermal crystallization of iPP was determined by the Kissinger method and showed that the addition of nucleating agents increased the activation energy. Melting behavior and crystalline structure of the nucleated iPPs are dependent on the nature of NAs and crystallization conditions. Higher proportion of β-phase can be obtained at higher content of β-nucleating agent and lower crystallization temperature or lower cooling rate.

Restricted access

(MWCNTs) and a rare earth (WBG), which may impose a dual nucleation impact on iPP. For this mixed nucleating system, MWCNTs act as α-nucleating agent to facilitate the formation of α-iPP, whereas the β-modification is arisen from the rare earth nucleating

Restricted access

structures of iPP are dependent on the composition of nucleating agents. It is found that the nucleating ability of α-nucleating agent was higher than that of β-nucleating agent for iPP crystallization. Although β-iPP possesses excellent thermal and

Restricted access

agent of PP was divided into α- and β-nucleating agent. PP nucleated by α-nucleating agent formed α-modification (α-PP) [ 6 – 15 ] with good rigidity, while PP nucleated by β-nucleating agent might form β-modification (β-PP) with special properties [ 16

Restricted access

PET is a weak α -nucleating agent for PP crystallization. Fig. 1 DSC crystallization curves of PP, β-PP and PP/PET blend The non-isothermal crystallization and

Restricted access