Crystallization behavior of polypropylene filled with surface‐modified calcium carbonate

Abstract

SYNOPSISPolypropylene (PP) and calcium carbonate ( CaC03) were mixed in a two-roll mill. The mixed compounds were molded on the plate by using a compression press heater. To improve the affinity of the relation between CaC03 and the PP matrix, we modified the CaC03 surface through chemical reaction with alkyl dihydrogen phosphates. The CaC03 content and size modification affected the crystallization behavior of the filled PP composites. The crystallization temperature in the nonisothermal crystallization process increased with the increase of CaC03 content and the decrease of CaC03 size. The crystallization temperature revealed the function of log( 1 + T s ) ( T s , total surface area of CaC03) irrespective of CaC03 content and size for modified and unmodified systems, respectively. The shoulder or double crystallization peak of PP composites is recognized for the unmodified system (particle sizes: 1.0 and 4.5 pm) .

Preparation and characterization of coverage-controlled CaCO3 nanoparticles

“…The general agreement about the nucleation effects of micro-sized CaCO 3 particles on polypropylene is that the uncoated CaCO 3 particles has a strong nucleation effect on the crystallization rate of polypropylene whereas fatty acid coating diminishes the nucleation effect [17,18]. However, only a few studies [19,20] asserted that stearic acid coated CaCO 3 nanoparticles do not act as a nucleating agent.…”

Nucleating effect of calcium stearate coated CaCO3 nanoparticles on polypropylene

“…It has generally been observed that uncoated micro-sized CaCO 3 particles have a moderate nucleating effect. This has been attributed to the interactions between the polymer chains and the particle surface [23]. However, stearic acid coating has been shown to diminish the nucleating effect [23,30] because PP filled with surface-modified CaCO 3 micro-particles has a lower crystallization temperature (T c ) than PP filled with uncoated micro-particles [23].…”

“…There have been many studies [23][24][25][26][27][28][29][30] of the crystallization behaviors of PP filled with coated micro-or nano-sized CaCO 3 particles. It has generally been observed that uncoated micro-sized CaCO 3 particles have a moderate nucleating effect.…”

Study on poly(propylene)/ammonium polyphosphate composites modified by ethylene‐1‐octene copolymer grafted with glycidyl methacrylate

“…At the same time, there are many experiments that showed that the filler's nucleation action was reduced after surface modification, especially when modified by a coupling agent having a long fatty chain. Mitsuishi et al 19 modified CaCO 3 with a series of phosphoric esters formed at the surface of CaCO 3 , which provided a coating that diluted the PP molecule chain near the CaCO 3 particle, so that the nucleation action decreased.…”