Thermal properties and processability of modified poly(L-lactide): the role of phenylacetic acid hydrazide derivative

Abstract

The influence of phenylacetic acid hydrazide (NAPAH) derivative content, melt temperature (170−200°C) and cooling rate (1−20°C/min) on poly (L-lactide) (PLLA) nucleation were investigated. Increasing the content of NAPAH (0.5−3.0 wt.%) had a positive effect on PLLA crystallization, while an increase in the cooling rate and heating temperature had a negative effect. In the case of isothermal crystallization carried out for a long time (180 min), the melting process depended only on the crystallization temperature. NAPAH also influenced the cold crystallization temperature, reduced thermal stability and improved PLLA processability (MFR).

Nucleating Agents to Enhance Poly(L-lactide) Crystallization and Melting Behavior of Modified Poly(L-lactide)

“…NCAPH's synthesis pathway is shown in Figure .1. The synthetic procedure is similar to that of other compounds reported by our research group [32,40], and there are two main reason steps, they are acylation and amination reaction. The resulting NCAPH is characterized by 1 H Nuclear Magnetic Resonance ( 1 H NMR) and Fourier Transform Infrared Spectrometer (FT-IR), the detailed characterization data are as follows: FT-IR (KBr) υ: 3379.9 cm -1 (the stretching vibrations absorption of N-H), 3257.7 cm -1 (C-H stretching vibration of 2-pyridine), 1678.1 cm -1 (the stretching vibration absorption of C=O which is near naphthalene), 1652.4 cm -1 (the stretching vibration absorption of C=O which is near 2-pyridine), 1590.7, 1570.3, 1490 and 1464.1 cm -1 (the vibration absorption of C-C of naphthalene and pyridine), 1515.6 cm −1 (N-H bending vibration absorption), 1328.7 cm −1 (the mixed absorption about bending vibration of N-H and stretching vibration of C-N), 1140.7 cm -1 (the stretching vibration of C-H of naphthalene), 998.5 cm -1 (the stretching vibrations absorption of C-C which located in C=O and naphthalene), 859.2 cm -1 (the out-of-plane bending vibration absorption of C-H of naphthalene).…”