Combinatorial Methods, Automated Synthesis and High‐Throughput Screening in Polymer Research: The Evolution Continues

The Introduction of the Radical Cascade Reaction into Polymer Chemistry: A One-Step Strategy for Synchronized Polymerization and Modification.

The preparation of uniform polymers and their use in fundamental polymer chemistry are reviewed. A typical method of preparation is a combination of living polymerization and supercritical fluid chromatography separation. Synthetic uniform polymers allow us to solve ambiguous problems in polymer chemistry due to molecular weight distribution and are of significant importance for studies on structure–property relationships. A close inspection of an isotactic uniform chloral oligomer with a symmetrical chemical structure reveals that oligomers are the first examples of stable atropisomers of aldehyde oligomers and that their chiroptical properties are due only to their helical geometries. A molecular‐level understanding of the mechanism and stoichiometry of the association process of polymer molecules is possible only with uniform polymers, and stereocomplex formation between isotactic and syndiotactic poly(methyl methacrylate)s in acetone has vigorously been studied by size exclusion chromatography (SEC) and NMR. End‐functionalized uniform polymers have enabled us to prepare uniform polymer architectures, such as block, graft, comb, and star polymers. A uniform stereoblock poly(methyl methacrylate) with an isotactic (methyl methacrylate)46‐syndiotactic (methyl methacrylate)46 structure shows a single SEC peak in chloroform but three peaks in acetone, which are ascribable to intermolecularly and intramolecularly associated complexes and nonassociated molecules. A three‐arm star polymer with one isotactic chain and two syndiotactic chains shows a peculiar SEC behavior in acetone due to a braid type of intramolecular stereocomplex formation. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 416–431, 2004

This issue of the MRS BULLETIN is devoted to a class of materials undergoing a transition from a period in which they were viewed primarily as cheap substitutes for other materials into a new period where polymers are seen as high tech, value-added materials in their own right. The six articles included here focus on a portion of the wide range of topical areas concurrently at the frontiers of polymer materials science.Polymers are molecules consisting of a large number of units (mers) covalently connected to form macromolecules of very high molar mass (upwards of 106). Polymer chemists have learned how to make an almost endless variety of highly complex yet well- defined macromolecules utilizing a wide variety of monomers. Once polymer physicists and materials scientists depended on industry to provide samples (which were far from model materials to work on). Today, significant improvements in chemical synthesis and a growing collaborative effort between polymer chemists and materials scientists have resulted in the availability of extremely well-defined materials (molecular weight distribution, composition, sequence of monomer types along the chain backbone, stereochemistry of these units and overall molecular architecture, e.g., branching vs. linear) for the attainment of novel properties and the investigation of structure-property relationships. Given the sophistication of current polymer synthesis, it is now possible to test structure-property hypotheses systematically and to rationally design macromolecules to form specified microstructures and provide desirable physical properties.The typical mental image conjured by the word polymer is an entangled mass of cooked spaghetti. This is in fact very appropriate for the class of flexible chain polymers in the noncrystalline state. The pioneering work of P.J. Flory in elucidating the nature of such materials, e.g., polymer melts and amorphous polymers above their glass transition temperature, made crucial use of the essentially Gaussian behavior of the end-to-end distance vector of a flexible chain polymer in the condensed state.

The structures of the French dairy industry has entered a phase of rapid reorganization in seven years, 1 705 dairy units (out of 6 000) have « disappeared ». After appreciating the importance of this concentration, the authors have tried to analyse the technical' and economic factors which influence the growth of dairy firms. The essential phenomenon is the growth of a small number of big firms. This' growth seems to take two main directions : — control of the market of new products — control of a high-consuming geographical area.

We have developed a novel approach combining high information and high throughput analysis to characterize cell adhesive responses to biomaterial substrates possessing gradients in surface topography. These gradients were fabricated by subjecting thin film blends of tyrosine-derived polycarbonates, i.e. poly(DTE carbonate) and poly(DTO carbonate) to a gradient temperature annealing protocol. Saos-2 cells engineered with a green fluorescent protein (GFP) reporter for farnesylation (GFP-f) were cultured on the gradient substrates to assess the effects of nanoscale surface topology and roughness that arise during the phase separation process on cell attachment and adhesion strength. The high throughput imaging approach allowed us to rapidly identify the "global" and "high content" structure-property relationships between cell adhesion and biomaterial properties such as polymer chemistry and topography. This study found that cell attachment and spreading increased monotonically with DTE content and were significantly elevated at the position with intermediate regions corresponding to the highest "gradient" of surface roughness, while GFP-f farnesylation intensity descriptors were sensitively altered by surface roughness, even in cells with comparable levels of spreading.

Nowadays, the pipelines of drug candidates leading to new small-molecule drugs are fed by leads selected from large compound libraries produced by parallel and combinatorial synthetic methods. Tibetan monks long ago discovered how to improve the effectiveness of their prayers by operating prayer wheels in parallel. In traditional chemistry, however, new compounds were synthesized and screened individually. A new era began in the second half of the last century. Following a few attempts, two new methods spread which significantly increased the efficiency of chemical synthesis and screening of compounds: the parallel and combinatorial methods.

This chapter briefly introduces combinatorial thin film synthesis techniques with applications to the development of new nanoelectronic materials. These methods are of interest because they allow the high-throughput synthesis of various materials, which is an important aspect of systematic investigations. Combinatorial synthesis is a general term for techniques capable of rapidly generating information regarding the properties of a material in conjunction with systematic variations in composition and fabrication parameters. Combinatorial thin film synthesis in particular is a relatively new research field that has expanded over the past two decades, with significant progress. As a result of this progress, libraries of thin film compositions based on inorganic and organic materials have been constructed. Combinatorial technologies together with new high-throughput evaluation and computing methods are vital to the preparation of these libraries, which are the basis of materials informatics.

In general, commercializing new technologies have many problems in the beginning of their lifecycle, especially the process relate to marketing. In case study of commercializing products from Research and Development of University, the commercialization scheme can be made by incubating products along with tenants in an incubator in collaboration with other parties who have capability in market testing (pre-test market). Pre-test market of new products with new technology requires new survey mechanism with many limitations of media survey (sample, market info, user, etc.). This article discusses about pre-test market methodology and the results of commercializing new technologies by using a case study of Eco-Absorber panel acoustic that commercialized by a start-up company. We proposed methodology by using SWOT analysis to determine 4P elements; using 2 stages survey to get appropriate STP, and analyzing the data by using reliability and validity test. Appropriate respondents were chosen by purposive sampling and have obtained data as many as 101 samples. This paper contributes to construct a methodology of pretest market for a new product with new technology to be ready for commercialization and to assist incubator and tenant in decision making for development and improvement product before it is launched into the market as well as product marketing. In conclusion, based on pre-market testing the product of the start-up company is obtained results that Eco-Absorber-ready by the development and improvement in some parts of the panel.

Nanocellulose-hydrogel hybrids: A review on synthesis and applications in agriculture, food packaging and water remediation.

Electrochemical energy storage devices are becoming increasingly important to our global society, and polymer materials are key components of these devices. As the demand for high-energy density devices increases, innovative new materials that build on the fundamental understanding of physical phenomena and structure–property relationships will be required to enable high-capacity next-generation battery chemistries. In this Review, we discuss core polymer science principles that are used to facilitate progress in battery materials development. Specifically, we discuss the design of polymeric materials for desired mechanical properties, increased ionic and electronic conductivity and specific chemical interactions. We also discuss how polymer materials have been designed to create stable artificial interfaces and improve battery safety. The focus is on these design principles applied to advanced silicon, lithium-metal and sulfur battery chemistries. Polymers are ubiquitous in batteries as binders, separators, electrolytes and electrode coatings. In this Review, we discuss the principles underlying the design of polymers with advanced functionalities to enable progress in battery engineering, with a specific focus on silicon, lithium-metal and sulfur battery chemistries.

Driven by the concern about the future petro-chemical feedstock availability, as well as the need for a green and sustainable society, renewable and bio-based materials have become the natural candidates for alternatives to petro-chemicals. As the most abundant biomass feedstock, carbohydrates are attracting significant attention from both academia and industry for the production of chemicals, fuels and energy. However, one major drawback of directly using carbohydrates in industrial processes is their limited thermal stability caused by the existence of multiple functional groups, for instance hydroxyl groups. Consequently, simplified or bi-functional carbohydrate-derived building blocks are often more attractive than the virgin carbohydrates for polymer chemists. In this thesis, we aim to 1) develop a new family of difunctional bio-based building blocks, and 2) utilize these new building blocks as AA monomers to synthesize step-growth polymers, such as polyesters and polyamides. Ideally, the new polymers are expected to be semicrystalline, preferably having high melting (Tm) and high glass transition temperatures (Tg), and can be used as the potential fully or partially bio-based engineering plastics. Isohexides (1,3:4,6-dianhydrohexitols), a group of secondary, rigid diols, as well as their derivatives are interesting carbohydrate-derived building blocks for various types of step-growth polymers, such as polyesters, polyamides and polycarbonates. Due to the intrinsic rigidity of the structures, isohexides are capable of increasing the glass transition temperatures when incorporated into polymers. However, the relatively poor reactivity of the secondary hydroxyl groups of isohexides has been recognized as a main drawback, which often results in low molecular weight or discolored polymers. In order to overcome these problems, as well as utilizing the rigidity of the isohexide skeleton, a new family of 1-carbon extended isohexide-derivatives were designed and synthesized by transforming the less reactive secondary hydroxyl functionalities into more reactive ones. Based on a key dinitrile intermediate, viz. isoididedinitrile (IIDN), the novel isohexide-derived building blocks were obtained. They are: isoidide-2,5-dicarboxylic acid (IIDCA) and its dimethyl ester (IIDMC), isoidide-2,5-dimethanol (IIDML) and isoidide-2,5-dimethyleneamine (IIDMA). After optimization of the respective synthetic routes, these building blocks were obtained at sufficient scales (5–20 g/batch) and high purities (>99.5%) to be suitable for polymerizations. Three series of polyesters based on the novel 1-carbon extended isohexides were synthesized. The first series of polyesters is based on isoidide dicarboxylic acid (IIDCA) and linear alkylene diols. Unexpectedly, they have rather low Tm (60–100 °C) values whereas the recorded low Tg values (-30–18 °C) were approximately expected. The second series of polyesters is fully based on renewable, isohexide-derived monomers. The combination of both isohexide-based AA/BB monomers gave significantly higher Tg values (45–85 °C) than the partially linear aliphatic polyesters of the first series. Importantly, this part of the project revealed the promising characteristics (reactivity, rigidity and thermal stability) of isoidide-2,5-dimethanol (IIDML) for potential applications in performance polymers with high Tg and Tm. Therefore, the third series of polyesters was entirely focused on IIDML-based semi-aromatic systems. The Tg and Tm values of these polyesters were found to exceed even those of the conventional PET and PBT polyesters, confirming our expectation that IIDML is a promising rigid cyclic diol for engineering plastic applications. Two series of semicrystalline (co)polyamides were synthesized from the new isoidide 2,5-dimethyleneamine (IIDMA) or from a mixture of IIDMA and 1,6-hexamethylene diamine with the biobased dicarboxylic acids sebacic acid or brassylic acid. A combination of melt polymerization of nylon salts with solid-state polycondensation (SSPC) processes afforded the desired copolyamides with maximum number average molecular weight (Mn) of 49,000 g/mol. Analysis by temperature dependent soldi state NMR and FT-IR spectroscopies revealed that the new diamine IIDMA exist in both the crystalline and amorphous phases of the copolyamides. Given the sufficiently high Tm values (~200 °C) of the copolyamides containing less than 50% of IIDMA, these bio-based semicrystalline copolyamides can be useful for engineering plastic applications. By comparing the thermal properties of the polymers based on the new isohexide-based building blocks, i.e. IIDCA, IIDML and IIDMA, with relevant reference polymers, systematic structure-thermal properties studies of each series of polymers were conducted. This work objectively evaluated the relative rigidities, reactivities and thermal stabilities of these new building blocks with respect to those of the parent isohexides, as well as with respect to their linear, cyclic aliphatic and aromatic analogues. Both the experimental (i.e., single crystal X-ray diffraction) and computational-aided methods (i.e., Density Functional Theory (DFT)) were employed to elucidate the structural characteristics of the isohexide-based building blocks, as well as to understand the specific thermal properties of the polymers based thereon. Additional efforts were invested to expand the dinitrile platform to the other stereo-isomers. The isomeric isohexide dinitriles were synthesized by base-induced epimerization. The strong non-nucleophilic organic base 1,8-diazabicycloundec-7-ene (DBU) was found to be a suitable catalyst for such type of isomerization. A kinetic study on the epimerization of three dinitrile isomers revealed an equilibrium between the three possible isomers in THF. Single crystal X-ray diffraction studies demonstrated several structural characters of these molecules regarding their symmetry and linearity. Density Functional Theory (DFT) calculations further supported the base-induced epimerization mechanism. This work concerns a pioneering study of deoxy-1-carbon-extended isohexide-based building blocks. All the monomers and polymers synthesized, characterized and evaluated in this thesis are entirely new. Suitable synthetic laboratory-scale protocols were developed for all the monomers and polymers. The reported study of the structure-thermal properties relations, as well as the crystal structure elucidation by single crystal X-ray diffraction and DFT, are also of high importance concerning the field of isohexide-based polymers and will certainly prove to be very useful for drawing conclusions on the industrial feasibility of such bio-based materials.

This article examines innovative activity of industrial corporations and their role in the emergence of the market of new products and technologies, its place in the innovation business.

Assistive technologies, such as telecare monitoring applications installed in the home, are being promoted to help reduce pressure on health care systems caused by an aging population and as such promise a large market for new products. However, despite many projects undertaken by commercial companies, and despite significant investments both by the companies and by national and international funding programs in the EU, such systems are not widespread. This paper reports on a retrospective study of the development of one early system, HandyHelper. We were interested in what challenges the development team faced and why the system is no longer on the market. Qualitative research methods were applied, including document analysis and interviews of key people involved in its development. Even though the system worked technically, the input of older users was sought, and a pilot installation was run, the development was stopped. The findings from a thematic analysis point to complex issues. Some problems were avoidable, e.g., by providing more support for new users, though other problems point to inherent tensions, such as the different needs of sensor-based security features and interactive services aimed at the older users. Yet other aspects are outside of the developer’s control, such as available public funding. We summarize these findings and suggest lessons learnt for future projects.

BackgroundTobacco use is a global health concern, with smoking initiation often beginning in adolescence. In Tunisia, published data assessing trends of tobacco consumption at the national level only concerns middle school students aged 13 to 15 years. No data related to high school students are however published yet. We aimed to determine tobacco smoking prevalence in Tunisian adolescents and assess trends from 2013 to 2021.MethodsPooled data from three Mediterranean school surveyson alcohol and other drugs (MedSPAD surveys: 2013, 2017, and 2021) were used. Based on three-stage stratification sampling method, teenagers aged between 15 and 17 years, were enrolled. Were not included students enrolled in vocational training centers and out-of-school adolescents. Data collection was performed using a self-administered standardized questionnaire assessing socio-demographic characteristics and risky behaviours. We studied weighted prevalence estimates of cigarettes and water pipe (WP) smoking. All statistical analysis, including trend analysis, were performed with STATA software.ResultsA total of 14.723 students were enrolled with sex ratio (M/F) equal to 0.6 and mean age of 16.2±0.8 years. The prevalence of cigarette smoking increased from 17.8%, to 20.2% then to 24.7% for 2013, 2017 and 2021, respectively. As for WP smoking, its prevalence increased from 14.8%, to 16.7% then to 19.9% for 2013, 2017 and 2021, respectively. Trends analysis concluded to significant increase over study period for cigarettes and WP smoking (p < 10-3). The increase was most alarming for girls regarding WP smoking (consistent increase over the study period).ConclusionsOur findings underscore the alarming increasing trend for different forms of tobacco smoking among Tunisian youth. It is therefore crucial to strengthen tobacco control measures among young adolescents in order to counteract the tobacco industry’s expanding marketing of new products primarily targeting this population.Key messages• The prevalence of cigarette and water pipe smoking increased significantly among high school Tunisian adolescents from 2013 to 2021.• A better commitment to the implementation of MPOWER measures for tobacco control is therefore urgent.

Changes in the duration of product life cycles (PLCs) have been identified as a driving factor for increasing the speed of new product development (NPD). However, the facilitating potential of increasing the speed to market of new products regarding their success has been subject to extensive debate. In this paper, we shed light on the long-run dynamics between PLC and key innovation performance indicators. A large secondary data set allows us to investigate long-run within-company differences. We observe significantly shrinking PLC on the one hand and significantly increasing NPD speed on the other. A change in the length of the PLC is positively linked to changes in time to market (Ttmarket) and time to volume. Also, we confirm a positive empirical relationship between shorter Ttmarket and quicker implementation of targeted quality and productivity. However, we cannot confirm a positive relationship between shorter Ttmarket and shorter time to break-even of investments.