Laser Powder Bed Fusion (LPBF) of thermoplastic polymers is an additive manufacturing (AM) technique experiencing a remarkable growth in the recent years. Nowadays most widely used materials are polyamides (PA12, PA11…) but massively available LPBF-compatible polyolefin powders recently arrived on market. The need understanding crystallization process for these new essential and this was addres...

By making use of an isothermal crystallization kinetics formulation in which growth and nucleation rates are functions the degree crystallization, we describe a process consisting birth spherical crystalline domains. It is found that beyond early stages role played by rate becomes quite insignificant as compared to domain rate. This contrast what would expect from simplified Avrami exponential ...

N, N'-oxalyl bis(piperonylic acid) dihydrazide (PAOD) was obtained through the amination of piperonylic acid chloride and its structure characterized by Fourier transform infrared spectrometer nuclear magnetic resonance. Melting blend technology used to prepare modified poly(L-lactic (PLLA) containing various loading PAOD as a new organic nucleating agent. The thermal performances including cry...

High-pressure (0.8 gigapascals) granulite facies garnet from Gore Mountain, New York, hosts multiple solid inclusions containing the low-pressure silica polymorph cristobalite along with albite and minor ilmenite. Identification of cristobalite is based on Raman spectra, electron microprobe analysis, and microthermometric measurements on the alpha/beta phase transformation. The cristobalite plu...

Molecular dynamics simulations are carried out on the isothermal crystallization process of single polyethylene chains with different chain lengths on the single wall carbon nanotube. This process is summarized as two steps, i.e., adsorption and orientation, and the bond-orientational order parameter is used to show the details of this process. The results show that the attractive van der Waals...

r(NJ Nucleation rates in condensed systems are frequently not at their steady state values. Such time dependent (or transient) nucleation is most clearly observed in devitrification studies of metallic and silicate glasses. The origin of transient nucleation and its role in the formation and stability of desired phases and microstructures are discussed. Numerical models of nucleation in isother...

The modified poly(L-lactic acid) (PLLA) with different contents (0.5−3 wt %) of N,N’-bis(phenyl) 1,4-naphthalenedicarboxylic acid dihydrazide (NAPH) were prepared to evaluate effects NAPH on melt-crystallization behavior (DSC), thermal degradation (TGA) and mechanical properties PLLA. results demonstrated that as a heterogeneous organic nucleating agent enhanced crystallization ability PLLA in ...