Lignin, nature’s dominant aromatic polymer, is found in most terrestrial plants in the range of 15–40% dry weight and provides structural integrity. Kraft lignin (KL) is a major by-product of pulp & paper industry where, hydrolysis lignin (HL) is the solid residue left from the enzymatic hydrolysis of wood after the pretreatment processes in cellulosic ethanol plants. Currently, most of the lignin is burned to generate heat and electricity and remaining is considered as a low value material. Only 1% of the annually produced lignin is being commercialized for its application in the preparation of bio-chemicals and to limited extent for bio-materials. Although with much lower reactivity, even crude lignin (a natural polyol) can be directly incorporated into polyurethane (PU) foam formulation due to the presence of aliphatic and aromatic hydroxyl groups in its structure as the reactive sites. However, bio-replacement ratios are usually low ~20–30% and further increasing replacement ratios results in fragile and low strength foams. Lignin depolymerization with selective bond cleavage is still a major challenge for converting it into value-added precursors especially for its utilization in the preparation of rigid PU foams. Depolymerization of these macromolecules can result in the valuable products with high hydroxyl number/functionality and low molecular weights, which in turn will increase the percentage replacement of bio-based polyols in the PU foam formulations. The technical routes/technologies for the depolymerization of lignins and their effective utilization as polyols in PU foams are summarized in this review article. These include direct utilization of lignin as well as the incorporation of depolymerized lignins, with and without modification, at high replacement ratios in PU foams. The major emphasis was given on the effective utilization of low value lignin for high value applications. Some of the associated challenges for the production of materials from lignin are also discussed.

Depolymerization of lignins and their applications for the preparation of polyols and rigid polyurethane foams: A review

Microreactor technology and continuous flow processing in general are key features in making organic synthesis both more economical and environmentally friendly. When preformed under a high-temperature/pressure process intensification regime many transformations originally not considered suitable for flow synthesis owing to long reaction times can be converted into high-speed flow chemistry protocols that can operate at production-scale quantities. This Focus Review summarizes the state of the art in high-temperature/pressure microreactor technology and provides a survey of successful applications of this technique from the recent synthetic organic chemistry literature.

Continuous Flow Organic Synthesis under High‐Temperature/Pressure Conditions

Provided is an organic thin film transistor comprising a self-assembled monolayer interposed between a gate dielectric and an organic semiconductor layer. The monolayer is a product of a reaction between the gate dielectric and a precursor to the self-assembled monolayer. The monolayer precursor composition has the formula: X-Y-Zn, wherein X is H or CH3; Y is a linear or branched C5-C50 aliphatic or cyclic aliphatic connecting group, or C8-C50 group comprising an aromatic group and a C3-C44 aliphatic or cyclic aliphatic connecting group; Z is selected from from -PO3H2, -OPO3H2, benzotriazolyl (-C6H4N3), carbonyloxybenzotriazole (-OC(=O)C6H4N3), oxybenzotriazole (-O-C6H4N3), aminobenzotriazole (-NH-C6H4N3), -CONHOH, -COOH, -OH, -SH, -COSH, -COSeH, -C5H4N, -SeH, -SO3H, -NC, -SiCl(CH3)2, -SiCl2CH3, amino, and phosphinyl; and n is 1, 2, or 3 provided that n = 1 when Z is -SiCl(CH3)2 or -SiCl2CH3. Methods of making a thin film transistor and an integrated circuit comprising thin film transistors are also provided.

Surface modifying layers for organic thin film transistors

A suitable cross-linkable matrix precursor and a poragen can be treated to form a porous cross-linked matrix having a Tg of greater than 300 °C. The porous matrix material has a lower dielectric constant than the corresponding non-porous matrix material, making the porous matrix material particularly attractive for a variety of electronic applications including integrated circuits, multichip modules, and flat panel display devices.

Composition containing a cross-linkable matrix precursor and a poragen, and a porous matrix prepared therefrom

A system for processing semiconductor substrates includes a front-end with at least two vertical levels of input/output ports for transferring substrate cassettes into or out of the housing of the processing system. The front-end also includes at least one level of storage positions, e.g., two levels of storage positions, which can be disposed between the two vertical levels of the input/output ports. The two vertical levels of storage positions can each be provided with two storage positions and each of two levels of input/output ports can be provided with accommodations for two cassettes, allowing for a total of eight cassettes to be accommodated at the front-end of the processing system. Inside the housing of the processing system, interior storage positions can be provided adjacent a wafer handling chamber and spaced apart from a cassette store having rotary platforms for housing cassettes. A single cassette handler can be used to access cassettes at each of the input/output ports and the interior storage positions.

Processing system with increased cassette storage capacity

An oligomer, uncured polymer or cured polymer comprising the reaction product of one or more polyfunctional compounds containing two or more cyclopentadienone groups and at least one polyfunctional compound containing two or more aromatic acetylene groups wherein at least some of the polyfunctional compounds contain three or more reactive groups. Such oligomers and uncured polymers may be cured to form cured polymers which are useful as dielectrics in the microelectronics industry, especially for dielectrics in integrated circuits.

Polyphenylene oligomers and polymers

Synthesis of 2,3‐dichloroquinoxalines via Vilsmeier reagent chlorination

Dow AgroSciences has been investigating a new family of functionalized 2,6-dihaloaryl 1,2,4-triazole insecticides featuring specifically targeted insecticidal activities coupled with low mammalian toxicity With broad spectrum control of both chewing and sap-feeding pests in mind, this family of compounds has been under investigation for aphid, mite, and whitefly control in food crop protection as well as ornamental applications Two specific targets for development have been the 2,6-dihalo 1,2,4-triazoles XR-693 and XR-906, which require a supply of the halogenated 2-thiophenecarboxylic acid derivatives 1, 2, and 3 for assembly of the C-ring portion of the triazole products

https://www.beilstein-journals.org/bjoc/content/pdf/1860-5397-3-23.pdf

Development of potential manufacturing routes for substituted thiophenes – Preparation of halogenated 2-thiophenecarboxylic acid derivatives as building blocks for a new family of 2,6-dihaloaryl 1,2,4-triazole insecticides

Development of Manufacturing Processes for a New Family of 2,6-Dihaloaryl 1,2,4-Triazole Insecticides

A new class of acid labile poly(aryl acetal) polymers has been developed that can be used in photoresist formulations for next-generation microlithography techniques including extreme ultraviolet (EUV) or electron beam lithography. Example polymers have been synthesized by an optimized Suzuki polycondensation protocol. They are soluble in common photoresist solvents but are insoluble in water or aqueous bases that are used to develop positive photoresists. The structural design includes further elements that are aimed at improving photoresist resolution, stability, and etch resistance. Upon acid exposure, the acetal linkages are cleaved, and the polymers degrade into phenolic terphenyl fragments, which are readily soluble in a photoresist developer. Polymer degradation has been studied by NMR and LC-MS. Lithographic formulations have been developed and tested in line-and-space patterning experiments using EUV photolithography. Optimized resist formulations achieved 22 nm resolution with line width roughne...

Duane R. Romer

Papers

Polyphenylene oligomers and polymers

Synthesis of 2,3‐dichloroquinoxalines via Vilsmeier reagent chlorination

Development of potential manufacturing routes for substituted thiophenes – Preparation of halogenated 2-thiophenecarboxylic acid derivatives as building blocks for a new family of 2,6-dihaloaryl 1,2,4-triazole insecticides

Development of Manufacturing Processes for a New Family of 2,6-Dihaloaryl 1,2,4-Triazole Insecticides

Backbone Degradable Poly(aryl acetal) Photoresist Polymers: Synthesis, Acid Sensitivity, and Extreme Ultraviolet Lithography Performance