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In the current work, calcium silicate (CaSiO3) was blended with the poly (L-lactic acid) (PLLA) to prepare the PLLA/CaSiO3 composites, and the crystallization process, melting process and thermal decomposition behavior of PLLA/CaSiO3 composites were studied. The promoting effect of CaSiO3 on the crystallization of PLLA was proved by the melt-crystallization, and the CaSiO3 content was a crucial factor to the crystallization behavior of PLLA. The crystallization temperature significantly affected the melting behavior of PLLA, and the double melting peaks degenerated into the single melting peak with the increasing of crystallization temperature from 90 °C to 130 °C. Additionally, for a given PLLA/CaSiO3 sample, the different melting processes in heating after the melt-crystallization results from the different heating rates, and the appearance of the cold-crystallization peak indicated the medium nucleation capacity of CaSiO3. The presence of CaSiO3 decreased the onset thermal decomposition temperature of PLLA, and this effect depended on the competitive relationship of the poor compatibility of PLLA with CaSiO3 and the content of CaSiO3 with high thermal stability.

In this work, four hydrocinnamic acid derivatives including N, N’-succinic bis(hydrocinnamic acid) dihydrazide (HASUD), N, N’-adipic bis(hydrocinnamic acid) dihydrazide (HAADD), N, N’-sebacic bis(hydrocinnamic acid) dihydrazide (HASED) and N, N’-dodecanedioic bis(hydrocinnamic acid) dihydrazide (HADOD) were synthesized via two liquid reactions. And then fourier transform infrared spectrometer and 1H nuclear magnetic resonance were used to characterize molecular structures of four hydrocinnamic acid derivatives. Additionally, the orthogonal experiment obtained the optimum synthesis process of four hydrocinnamic acid derivatives, and the maximum yield of HASUD, HAADD, HASED and HADOD were 33.3%, 43.2%, 43.5% and 51.9%, respectively. DMol3 was used to optimize geometric structure and obtain frontier orbital energy. Finally, hydrocinnamic acid derivatives and poly(L-lactide) (PLLA) were blended using the torque rheometer to investigate these role in PLLA resin. The resultant from the melt-crystallization process showed that hydrocinnamic acid derivatives as heterogeneous nucleating agents could significantly enhance PLLA’s crystallization.

In this study, N, N’-carbonic bis(piperonylic acid) dihydrazide (BPACH) was synthesized to broaden the category of piperonylic acid derivative and evaluate its influences on the thermal properties of poly(L-lactic acid) (PLLA). The geometry optimization of BPACH showed that the highest occupied molecular orbital mainly focused on the formed amide group and carbonic dihydrazide, whereas the lowest unoccupied molecular orbital mainly focused on the piperonylic acid, and the orbital energy gap was 0.10418 eV. The differences in melt-crystallization processes of the neat PLLA and PLLA/BPACH samples indicated that the BPACH could provide the effective nucleation site to accelerate the crystallization of PLLA, but the crystallization accelerating effect was still further improved compared to some reported nucleating agents. The melting behaviors of PLLA/BPACH samples after crystallization depended on the crystallization temperatures and heating rates; additionally, the melting processes could also effectively reflect the previous crystallization behaviors.

In this study, the potential effects of N, N' -dodecanedioic bis(cyclopentanecarboxylic acid) dihydrazide (BCADD) as a new additive in poly(L-lactic acid) (PLLA) was estimated. The comparative study on the melt-crystallization showed that the BCADD as heterogeneous nuclei facilitated crystallization of PLLA in cooling, which indicated by the obvious crystallization exotherms and sharp melt-crystallization peak. Unfortunately, with increasing of BCADD from 0.5 wt% to 3 wt%, it is unexpected that the melt-crystallization peak of the BCADD-nucleated PLLA shifted toward the lower temperature and became flatter, evidencing the importance of BCADD loading for PLLA's crystallization. Additionally, the cooling rate and the final melting temperature were also proved to be important influence factors during PLLA's melt-crystallization process, but in contrast with the effect of the final melting temperature on the melt-crystallization, a higher cooling rate could more seriously weaken crystallization ability of the BCADD-nucleated PLLA. The chemical nucleation mechanism was proposed to explain the promoting effect of BCADD on the crystallization of PLLA via the analysis of frontier orbital energy. The melting behaviors after crystallization further confirmed the crystallization accelerating role of BCADD, and the melting behaviors were affected by the heating rate, crystallization temperature and BCADD loading. Although the onset thermal decomposition of the BCADD-nucleated PLLA occurred at lower temperature comparing with the pure PLLA, the intermolecular interaction of PLLA with BCADD attempted to prevent the decrease of thermal stability. Overall, the addition of BCADD resulted in the complicated effect on the tensile modulus and tensile strength of PLLA, but the elongation at break continuously decreased when increasing BCADD loading. [ABSTRACT FROM AUTHOR]

The allergic reaction (AR) of Chinese herbal injection (CHI) has become one of the most noticeable focuses of public health in China. However, it still remains a considerable controversy as to whether low‐molecular‐weight components in CHI have potential sensitization. In this study, the relationship between AR and low‐molecular‐weight component profile of Shenmai injection was explored by an interdisciplinary technology integrating real‐world evidence and ultra‐performance liquid chromatography–quadrupole time‐of‐flight mass spectroscopy (UPLC–Q‐TOF‐MS). The AR information of hospitalized patients was obtained by comprehensively analyzing real‐world evidence from January 2015 to June 2019 at two Chinese hospitals. The UPLC–Q‐TOF‐MS was exploited to systematically investigate the low‐molecular‐weight component profile with 50–1500 m/z mass range, and 3725 MS1 peaks were detected. The optimized partial least squares discriminant analysis model was established to map the influence of low‐molecular‐weight components on AR. The results of this study showed that high levels of organic acids administered intravenously might be a potential risk factor for inducing AR. By using this method, Shenmai injection with high AR risk could be recognized precisely with 100% accuracy before clinical use. [ABSTRACT FROM AUTHOR]