Abstract
In this work, biodegradable Poly(L-lactide) (PLLA) was modified through adding a new organic additive N, N -bis(benzoyl) 1, 4-naphthalenedicarboxylic acid dihydrazide (NABH). A comparison on crystallization of the pure PLLA and PLLA/NABH revealed that the NABH as effective heterogeneous nucleation sites enhanced PLLA𠏋 crystallization, and an increase of NABH loading was able to further accelerate crystallization rate of PLLA; whereas a faster cooling rate was not conducive to PLLA𠏋 crystallization, but the appearance of obvious crystallization peak upon cooling at 30şC/min confirmed the advanced enhancing role of NABH for PLLA crystallization again. The investigation on influence of the final melting temperature on the crystallization behavior of PLLA showed that the 170 şC was optimum final melting temperature for enhancing crystallization, even the onset crystallization temperature of PLLA/NABH were higher than 150şC. The melting processes of PLLA/NABH after different crystallization not only could reflect the previous crystallization, but also depended on crystallization temperature and heating rate. Thermal decomposition results showed that the existence of NABH slightly weakened thermal stability of PLLA, and the maximum difference in onset thermal decomposition temperature was only 9.4şC comparing with the pure PLLA. However, the presence of NABH in PLLA matrix seriously weakened optical property.
Highlights
Solid waste pollution from the fossil-based and non-degradable polymeric products has led to a severe crisis for promoting social sustainable development, what is worse, up to now, the large-scale usage of non-degradable polymeric products has not been still reduced
The 1, 4-naphthalenedicarboxylic acid dichloride was subsequently added into a solution including 0.006 mol benzoic hydrazide, 100 mL DMF and 3 mL pyridine, the mixture was stirred at ice bath for 1.5 h, heated up to 60°C to keep stirring for 3 h, the resulting solution was poured into 300 mL distilled water, the crude product was obtained by filtration method, and the crude product was further washed by distilled water for three times to obtain the final white product naphthalenedicarboxylic acid dihydrazide (NABH)
In contrast with the pure PLLA, the melt-crystallization peaks of all PLLA/NABH samples can be detected in DSC thermograms, the meltcrystallization peaks observed in DSC thermograms are very sharp, suggesting that the presence of NABH as effective heterogeneous nucleation sites is able to enhance crystallization ability and accelerate crystallization rate of PLLA
Summary
Solid waste pollution from the fossil-based and non-degradable polymeric products has led to a severe crisis for promoting social sustainable development, what is worse, up to now, the large-scale usage of non-degradable polymeric products has not been still reduced. Poly(L-lactide) (PLLA) produced from renewable sources is widely known as a commercially available thermoplastic [2] with excellent degradability and compatibility [3, 4], easy processing [1, 5], appropriate mechanical performances [6, 7], etc. These advantages endow PLLA with promising applications in different fields, mostly for packaging materials [8,9,10], biomedical materials [11,12,13] and 3D printing materials [14,15,16]. Adding physical nucleating agent is thought to be an easy industrialization way to accelerate crystalli-
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
