Monomers derived from glucose and galactose, which contain an endocyclic alkene (in the sugar ring) a terminal alkyne, underwent cascade polymerization to prepare new polymers with ring-opened incorporated into polymer backbone. Polymerizations were well-controlled, as demonstrated by linear increase in molecular weight monomer-to-initiator ratio generally narrow dispersity values. The living nature of was supported preparation block copolymer two different sugar-based monomers. resulting...

Size-tunable semiconducting two-dimensional (2D) nanosheets from conjugated homopolymers are promising materials for easy access to optoelectronic applications, but it has been challenging due the low solubility of homopolymers. Herein, we report size-tunable and uniform 2D nanorectangles via living crystallization-driven self-assembly (CDSA) a fully polyenyne homopolymer prepared by cascade metathesis metallotropy (M&M) polymerization. The resulting with enhanced successfully underwent CDSA...

We demonstrate the first example of cascade polymerization by combining olefin metathesis and metallotropic 1,3-shift reactions to form unique conjugated polyenynes. Rational design monomers enabled controlled polymerization, kinetic investigation mechanism was conducted.

Understanding the stability and reactivity of propagating species is critical in living polymerization. Therefore, most olefin metathesis polymerizations require stabilization catalyst by coordination external ligands containing Lewis basic heteroatoms, e.g., phosphines pyridines. However, some cases, chemists postulated that metal carbene could also be stabilized chelation. Here, we disclose stable 16-electron olefin-chelated Ru carbenes play a key role previously reported living/controlled...

Abstract Enyne monomers derived from D‐xylose underwent living cascade polymerizations to prepare new polymers with a ring‐opened sugar and degradable linkage incorporated into every repeat unit of the backbone. Polymerizations were well‐controlled had character, which enabled preparation high molecular weight narrow dispersity values block copolymer. By tuning type acid‐sensitive (hemi‐aminal ether, acetal, or ether functional groups), we could change degradation profile polymer identity...

For decades, cyclopolymerization of α,ω-diyne derivatives has been an effective method to synthesize various soluble polyacetylenes containing five- seven-membered rings in the backbone. However, form four-membered carbocycles was considered impossible due their exceptionally high ring strain (∼30 kcal/mol). Herein, we demonstrate successful rationally designed 1,5-hexadiyne afford highly strained cyclobutenes each repeat unit. After screening, Ru catalysts bulky diisopropylphenyl groups...

Cyclopolymerization (CP) of 1,6-heptadiynes using olefin metathesis catalysts is a useful method for producing various conjugated polyenes. Unfortunately, commercially available user-friendly Grubbs have long been known to be inactive toward CP. However, recent mechanistic studies revealed that the problem did not lie with intrinsic activities but stability propagating carbenes, as decomposed carbene species catalyzed [2 + 2 2] cycloaddition side reaction instead Fortunately, by adding...

Until recently, the cyclopolymerization (CP) of 1,6-heptadiyne derivatives using Grubbs catalysts had been unsuccessful, leading to misbelief that these were inactive in circumstances. However, a recent breakthrough has changed this previous perspective CP, where successful living CP was reported third-generation catalyst with aid weakly coordinating ligands. Although it became clear ligands greatly enhanced efficiency by suppressing decomposition propagating carbene, still unclear as what...

On the basis of a combined experimental and computational study, novel method for preparing fully conjugated polyenynes via cascade metathesis metallotropy (M&M) polymerization various multialkynes is developed. DFT calculations elucidate detailed mechanism metallotropic 1,3-shift, which key process M&M polymerization. An α,β-(C,C,C)-agostic interaction stabilizing metallacyclobutadiene transition state found to be critically important successful with excellent specificity. The efficiency...

We have studied ion transport in electrolytes created by blending two different polymers and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). The covered this study are poly(ethylene oxide) (PEO), poly(1,3,6-trioxocane) (P(2EO-MO)), poly(1,3-dioxolane) (P(EO-MO)). Ion is quantified the product κρ+ which defined as efficacy of electrolytes, where κ conductivity ρ+ current fraction determined Bruce–Vincent method. Polymer blends can be either one-phase or macrophase-separated. used...

Cascade metathesis and metallotropy (M&M) polymerization, which involves sequential olefin metallotropic 1,3-shift reactions specifically from multiyne monomers, is the only method reported so far to prepare conjugated polyenynes via chain-growth mechanism. Using this method, various containing cyclopentene units in backbone could be synthesized exclusive α-addition by using third-generation Grubbs catalyst. Herein, we demonstrate complete switch of regioselectivity toward β-addition a Ru...

Polymer electrolytes enhance the safety of lithium-ion battery systems, but current state-of-the-art poly(ethylene oxide)-based polymer fail to achieve electrochemical properties necessary for practical applications. We probed impact substituent density on electrolyte performance by introducing methyl substituents into backbone a series poly(1,3-dioxolane) (PDXL)-based copolymers. The polymerization 1,3-dioxolane (DXL) and 4-methyl-1,3-dioxolane (MeDXL) yielded random copolymers that were...

The organic non-chemically amplified resist (non-CAR) materials have been developed for fine pitch contact hole patterning process to remove the acid blur of conventional chemically (CAR) system, but non-CAR usually show lower contrast and sensitivity compared CAR materials, so additional improvements are needed practical application. In this study, we new platforms EUV PTD overcome these limitations enable C/H patterning. main target our study is reduce maintain chemical system by 1)...

Abstract Enyne monomers derived from D‐xylose underwent living cascade polymerizations to prepare new polymers with a ring‐opened sugar and degradable linkage incorporated into every repeat unit of the backbone. Polymerizations were well‐controlled had character, which enabled preparation high molecular weight narrow dispersity values block copolymer. By tuning type acid‐sensitive (hemi‐aminal ether, acetal, or ether functional groups), we could change degradation profile polymer identity...

시설물의 유지관리 측면에서 수명의 연장 및 안전의 확보를 위한 보수 보강의 체계적인 기준 정립 필요성에 대한 요구가 늘어나고 있다. 이를 위해서는 특히, 사용되는 재료의 품질과 보강 시공 후의 품질관리를 지침이나, 매뉴얼, 등의 개발이 필요하다. 안전관리에 특별법(이하 시특법) 제정 이후 지난 17년 동안 보강에 많은 연구가 수행되었지만 현재 국내에서 그것과 관련된 공식적인 지침은 아직까지 없는 실정이다. 이에 본 논문에서는 보강기준 마련을 방향 제시를 위해 우선적으로 국내와 국외(미국, 일본, 유럽) 현황을 분석하였다. 내용을 중점적으로 검토하여 가이드를 3단계(설계, 시공, 검사)로 구분하여 분석한 뒤 토대로 기술의 품질 향상을 마련의 방향을 제시하였다. In terms of maintenance facilities demands need about establishment methodical standard repair and strengthening for extend...

초록 · 키워드 목차 오류제보하기 등록된 정보가 없습니다. #chain end-functionalized polymer #di(2-pyridyl)ketone #dipyridine-terminated #Living anionic polymerization

D-Xylose kann in ein polymerisierbares Monomer auf der Basis von Enin-Zucker umgewandelt werden, wie dem Titelbild zu sehen ist. Eingekreidet sind die erzielten Eigenschaften abbaubaren Polymere. Bei Polymerisation entwickelt sich abgeleitetes einer vollständigen Polymerkette, unter leicht sauren Bedingungen abgebaut werden kann, Tae-Lim Choi et al. ihrem Forschungsartikel S. 862 erklären. Der Akt des Zeichnens grober Ideen eine Tafel und Verwirklichung dieser molekularer Ebene wird durch...