Highly toughened polylactide with novel sliding graft copolymer by in situ reactive compatibilization, crosslinking and chain extension

YesThe “sliding graft copolymer” (SGC), in which many linear poly-ε-caprolactone (PCL) side chains are bound to cyclodextrin rings of a polyrotaxane (PR), was prepared and employed to toughen brittle polylactide (PLA) with methylene diphenyl diisocyanate (MDI) by reactive blending. The SGC was in situ crosslinked and therefore transformed from a crystallized plastic into a totally amorphous elastomer during reactive blending. Meanwhile, PLA-co-SGC copolymer was formed at interface to greatly improve the compatibility between PLA and SGC, and the chain extension of PLA also occurred, were confirmed by FTIR, GPC, SEM, and TEM. The resulting PLA/SGC/MDI blends displayed super impact toughness, elongation at break and nice biocompatibility. It was inferred from these results the crosslinked SGC (c-SGC) elastomeric particles with sliding crosslinking points performed as stress concentrators and absorbed considerable energy under impact and tension process.This work was supported by the National Natural Science Foundation of China (50933001, 51221002 and 51320105012)

Nucleation and crystallization in bio-based immiscible polyester blends

Bio-based thermoplastic polyesters are highly promising materials as they combine interesting thermal and physical properties and in many cases biodegradability. However, sometimes the best property balance can only be achieved by blending in order to improve barrier properties, biodegradability or mechanical properties. Nucleation, crystallization and morphology are key factors that can dominate all these properties in crystallizable biobased polyesters. Therefore, their understanding, prediction and tailoring is essential. In this work, after a brief introduction about immiscible polymer blends, we summarize the crystallization behavior of the most important bio-based (and immiscible) polyester blends, considering examples of double-crystalline components. Even though in some specific blends (e.g., polylactide/polycaprolactone) many efforts have been made to understand the influence of blending on the nucleation, crystallization and morphology of the parent components, there are still many points that have yet to be understood. In the case of other immiscible polyester blends systems, the literature is scarce, opening up opportunities in this environmentally important research topic.The authors would like to acknowledge funding by the BIODEST project ((RISE) H2020-MSCA-RISE-2017-778092

Studies on the Interaction in the Metabolism of Two Species of Bacteria Part Two: Interaction in the production of acetoin

As reported in the previous paper, it has been demonstrated that the acceleration of O(2)-consumption is greatest in the case of the substrate glucose, while the interaction likewise seems to occur in the case of RQ. Moreover, since if being evident that the RQ value parallels with the production of acetoin, the present experimcnt has been conducted in order to trace the mechanism involved in the production of pyruvate and acetoin. Bacteria used: E. coli communis, A. aerogenes, Staphylococcus albus, and Staphylococcus aureus. Substrates: glucose, pyruvate, lactate, succinate, and acetate. Inhibiting agents: DNP and NaN(3). 1. In the case of the substrate glucose, an interaction has been found to be involved in the production of acetoin, and its adequate pH seems to be 5.8-7.2. 2. The acetoin production in. the case with the use of the bacteria in the process of growth, has been nearly the same as that in the case with resting cells; and that with A. aerogenes especially pronounced. 3. In the case of the substrate pyruvate, hardly no acetoin production can be recognized. 4. In the case of the combination of E. coli with Staph. albus, which is cooperative in the acetoin production, it seems that acetoin is produced by E. coli utilizing of the decomposition products of glucose produced by albus. As for the combination of A. aerogenes with Staph. albus, it appears to be possible to assume that in the decomposition of glucose by A. aerogenes, the accumulation of pyruvate and other acids results in the lowering of pH so that acetoin production capacity of Staph. albus is activated. On the other hand, in the inhibitory combination of E. coli with Staph. anreus, it appears that E. coli might consume acetoin produced in the decomposition of glucose by Staph. aureus

Studies on the Interaction in the Metabolism of Two Species of Bacteria Part One: Interaction in O(2)-Consumption

The present experiment has been conducted with a view to study the interaction of two species of bacteria from the metabolic aspects; and as a preliminary, O(2)-consumption and RQ have been measured: Bacteria used: E. coli communis, A. aerogenes, Staphylococcus albus, and Staphylococcus aureus. Substrates: glucose, pyruvate, acetate, and formate. Inhibitory agents: KCN, DNP and NaN(3). 1. Since the O(2)-consumption in the case of the substrate glucose, is accelerated most markedly, it signifies that there is an interaction. 2. The RQ in the case of the substrate glucose has shown a greater increase when two combinations of E. coli and Staph. albus and that of A. aerogenes and Staph. albus are made to act at the same time than in the cases of individual bacterium made to act separately; while the RQ in the combination of E. coli with Staph. aureus has rather tended to decrease, and moreover, its acetoin production has been found to proceed in parallel with the value of RQ. 3. In the case of the inhibitory agent KCN, a marked inhibition of the O(2)-consumption has been revealed, while in the cases of NaN3 and DNP, an acceleration. Especially in the case of NaN(3) an acceleration of O(2)-consumption has been found; and in the combination of E. coli and Staph. albus with A. aerogenes and Staph. albus, the O2-consumption has been accelerated and its interaction striking. 4. In the case of an addition of the inhibitory agent NaN(3), RQ has been found to give a rather similar result as that in article 2, though with a slight lowering tendency. 5. In the case without NaN3, the interaction in the acetoin production presents a similar tendency as that revealed in the case of RQ. With the addition of NaN(3), the acetoin production has been inhibited. Therefore, it seems that due to an inhibition of the pyruvate to acetoin pathway by NaN(3), no acetoin production can be observed while an accumulation of pyruvate is to be expected

Liberal Arts Education as Organizational Knowledge Creation : From the perspective of Knowledge Management

The purpose of this study is to identify the role of the liberal arts education as organizational knowledge creation in the knowledge-based society from the perspective of knowledge management. Firstly, this paper discusses the distinguished characteristics of the knowledge-based society. It also touches on what is demanded for the social structure and social management in the knowledge-based society in which knowledge is considered as a higher level concept than data and information. Secondly, the paper makes an analysis of the issue concerning the liberal arts education in Japan. By making a brief review of the history of the Japanese liberal arts education, the paper discusses an increased emphasis on the importance of the liberal arts in Japan in recent years. Thirdly, the paper examines the liberal arts education as organizational knowledge creation. Moreover, it explains the liberal arts education by using the SECI Model (the process model of organizational knowledge creation) which is regarded as a foundational model of knowledge management. The SECI Model has four modes. They include Socialization, Externalization, Combination, and Internalization. The paper identifies the characteristics of these four modes in light of the content of liberal arts education. Fourthly, the paper discusses what is required for university and college students, including the issue concerning the phronesis and the phronetic leadership, in the knowledge-based society. Furthermore, the paper argues the reason why the phronesis and the phronetic leadership are needed in the knowledge-based society. By quoting P.F.Drucker's word, “Management is what tradition used to call a liberal art", the paper explores the interrelationship between the phronesis, the liberal art, and the liberal arts education

Structure and Properties for Biomass-Based Polyester Blends of PLA and PBS

Structure and properties are studied for binary blends composed of poly(lactic acid) (PLA) and poly(butylene succinate) (PBS). The rheological measurements in the molten state reveal that the entanglement molecular weight of PLA is lower than that of PBS. Further, the interfacial tension of the immiscible blend system is evaluated employing a rheological emulsion model and found to be 3.5 [mN/m]. Moreover, thermal analysis directly detects that addition of PBS enhances the crystallization of PLA even though PBS is in a molten state. Further, the cold-crystallization for quenched blends occurs at lower temperature than that for a quenched PLA. This would be attributed to the nucleating ability of PBS, leading to generation of PLA crystallites during the quench operation

マーケティングにおけるインターネット調査の実状と課題

要旨なし統計数理研究所研究活動公開講演会要旨　2000.11.