In this article, kinetics of neat poly(lactic acid) (PLA) and its blends with triphenyl phosphate (TPP) and/or talc crystallized isothermally in the temperature range of 113-128 C was analyzed by differential scanning calorimetry (DSC) and described by the Avrami equation. The results showed that the average value of Avrami exponents n is around 2.0 for neat PLA and the PLA/ 15TPP blend, and around 3.0 for the PLA/1.2Talc blend and the PLA/15TPP/1.2Talc blend. The crystallization rate constants k for neat PLA and its blends were increased in the following order: the PLA/15TPP blend, neat PLA, the PLA/15TPP/1.2Talc blend, and PLA/1.2Talc blend. The half-time of crystallization t 1/2 was increased with an increase of crystallization temperature T c and the presence of TPP, and was decreased sharply with the incorporation of talc. Further investigation into crystallization activation energy DE a of neat PLA and its blends with 15 wt % TPP and/or 1.2 wt % talc showed that the values of DE a were increased with the incorporation of TPP and/or talc compared to that of neat PLA. It was verified by wide angle X-ray diffraction (WAXD) that neat PLA and its blends with TPP and/or talc crystallized isothermally in the temperature range of 113-128 C, and all formed the a-form crystal after enough annealing time.

Eucommiae Cortex (EC), a rare, nourishing medicinal herb that is native in China, has good effect in the treatment of hypertension. In this study, we compared tissue distribution of six representative active components of EC extract—genipinic acid (GA), protocatechuic acid (PCA), neochlorogenic acid (NCA), chlorogenic acid (CA), (+)-pinoresinol di-O-β-D-glucopyranoside (PDG), and (+)-pinoresinol 4′-O-β-D-glucopyranoside (PG)—between normal rats and spontaneously hypertensive rats (SHRs). Each rat was intragastrically given EC extract at a dose of 5.4 g/kg. Rats were sacrificed at 10 min, 30 min, 2 h, and 8 h after administration; six rats were sacrificed at each time point. Then, we quickly harvested their major organs, including heart, liver, spleen, lungs, kidneys, and brain. Using ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), we determined the levels of the above mentioned six components in the organs of both types of rats and then analyzed differences in the tissue distribution. The results showed that levels of each component differed between SHRs and the normal group at each time point. As time progressed, the number of organs in which GA distribution in each tissue of SHRs differed from that of the normal group gradually increased: SHRs showed lower GA levels than normal rats. Levels of PG and PDG in both groups at 10 and 30 min were similar. NCA and CA in the SHR group and the normal group at 10 min, 30 min, and 2 h were also similar to some extent. The results indicated that the pathological state of spontaneous hypertension could affect tissue distribution of EC active components in rats.

The important practical problem of poor heat stability of poly(l‐lactic acid) (PLLA) is addressed by the addition of N, N′‐bis (benzoyl) sebacic acid dihydrazide (BSAD) and talc as a nucleating agent system. The idea of incorporating talc into the PLLA/BSAD composites is that talc can provide supplementary nucleation effect with very small amount of BSAD (0.2 wt %) and therefore can improve the heat deflection resistance of PLLA materials. Effects of BSAD/talc on morphology, crystallization behavior, heat resistance, and mechanical properties of PLLA/BSAD/talc were investigated after annealing processes. The results indicated that the BSAD/talc system increased the crystallinity from 6.0% of pure PLLA to a maximum 42.9% by the synergistic effects of BSAD and talc increasing the growth of spherulites and nucleation density, respectively. After annealing at different temperatures, the heat deflection temperature (HDT) of PLLA was improved dramatically due to synergistic effects of BSAD/talc between restricted chain movement and acceleration of crystallization. At high temperature (above Tg), the thermo‐mechanical properties of PLLA is mainly determined by the crystallinity and the reinforcement effect of talc acted as a filler. Moreover, effects of BSAD/talc on mechanical properties were discussed. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41454.

In this paper, a hydrophobic monomer (HM) that has a cationic double alkyl-substituted group bonded to the nitrogen atom was first synthesized. Then a hydrophobic poly(vinyl alcohol) (PVA) was prepared by a radical solution copolymerization of vinyl acetate (VAc) with the HM followed by an alcoholysis reaction in alkaline conditions. The structures of HM and hydrophobically modified PVA (H-PVA) were confirmed by Fourier transform infrared spectroscopy and nuclear magnetic resonance. The effect of hydrophobic cationic segments on crystallization behaviors, mechanical properties, morphology, solution viscosity, and hydrophobic property were investigated. The results indicated that the crystallinity decreased from 37.2% of pure PVA to the minimum 23.2% of H-PVA with the incorporation of 1.15 mol % HM. The thermal decomposition temperature of H-PVA increased by about 50 8C compared with that of pure PVA. The viscosity of the H-PVA solution was several times higher than that of the corresponding unmodified PVA solution over the whole shear rate range, which demonstrated that the H-PVA had good shear-resistance ability. Furthermore, the contact angle was significantly increased from 55.18 to 1158 with the incorporation of only 0.83% HM, which illustrated that the H-PVA had high hydrophobicity.

In this study, inclusion complexes (ICs) between host hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD) and guest poly(vinyl alcohol) (PVA) were prepared through polymer processing with water as plasticizer and solvent. The structure of PVA/HP‐β‐CD ICs was confirmed by FTIR, 1H‐NMR and 2D‐NOESY NMR. The yields of PVA/HP‐β‐CD ICs were 62.5%, 51.4%, and 46.8% in twin‐screw, rotor and single‐screw processing, respectively. The crystallinity, thermal properties and mechanical properties of the PVA/HP‐β‐CD ICs were characterized by X‐ray diffraction, differential scanning calorimetry, thermal gravimetric analysis and tensile tests, respectively. The results indicated that HP‐β‐CD could establish strong interfacial interaction with PVA through hydrogen bonding and form ICs with PVA. As a result, crystallinity and melting temperature decomposition temperature of PVA were decreased. Compared with pure PVA, PVA/HP‐β‐CD ICs exhibited remarkable improvement in thermal stability. Moreover, the tensile strength, elongation at break and torque of ICs with different content of HP‐β‐CD were discussed. POLYM. ENG. SCI., 55:1988–1993, 2015. © 2014 Society of Plastics Engineers