Vinyl Products Research Articles

Vinylic C-H Activation of Styrenes by an Iron-Aluminum Complex.

The oxidative addition of sp2 C-H bonds of alkenes to single-site transition-metal complexes is complicated by the competing π-coordination of the C═C double bond, limiting the examples of this type of reactivity and onward applications. Here, we report the C-H activation of styrenes by a well-defined bimetallic Fe-Al complex. These reactions are highly selective, resulting in the (E)-β-metalation of the alkene. For this bimetallic system, alkene binding appears to be essential for the reaction to occur. Experimental and computational insights suggest an unusual reaction pathway in which a (2 + 2) cycloaddition intermediate is directly converted into the hydrido vinyl product via an intramolecular sp2 C-H bond activation across the two metals. The key C-H cleavage step proceeds through a highly asynchronous transition state near the boundary between a concerted and a stepwise mechanism influenced by the resonance stabilization ability of the aryl substituent. The metalated alkenes can be further functionalized, which has been demonstrated by the (E)-selective phosphination of the employed styrenes.

Ligand and Substrate Effects on Regio‐ and Stereoselective Ru(II)‐Catalyzed Hydroacyloxylations to Vinylic Esters

AbstractTwo Ru(II)‐catalytic systems were developed for anti‐Markovnikov regioselective hydroacyloxylations of terminal alkynes to vinylic esters. [Ru(NCCH3)6][(BF4)2] favors (E)‐vinylic ester products with arylacetylenes and select carboxylic acids, whereas a Ru scorpionate complex with two electron‐withdrawing ligands favors (Z)‐vinylic ester isomers.

Metakrylan 2,3-epoksypropylu (metakrylan glicydylu) Dokumentacja proponowanych dopuszczalnych wielkości narażenia zawodowego

2,3-Epoxypropyl methacrylate (glycidyl methacrylate, GMA) is an organic chemical compound, an ester of methacrylic acid and 2,3-epoxypropan-1-ol. It is a colorless liquid with a fruity odor. It is used as a co-monomer for the production of epoxy polymers, as an adhesion promoter and cross-linking co-monomer in the production of vinyl and acrylic resins. This substance is on the ACSH (The Advisory Committee on Safety and Health at Work) priority list for developing a proposal for an EU limit value. So far, no normative values in the air of the working environment have been defined in Poland in regard of 2,3-epoxypropyl methacrylate. The MAC value of 0,3 mg/m3 and STEL value of 0,6 mg/m3 have been proposed. The basis for calculating the MAC value was the LOAEC value of 3,55 mg/m3 for the irritation of the nasal epithelium in mice (olfactory epithelium metaplasia). Taking into account the carcinogenicity of GMA and its effect on the skin, the following notations have been proposed: “Carc. 1B” – carcinogenic substance of hazard category 1B, “C” – corrosive substance, “A” – skin sensitizing substance, “Ft” – fetotoxic substance, and “Skin” – skin absorption of the substance may be just as important as for inhalation exposure. There is no basis for setting BEI value.

Nickel/Copper Co‐catalyzed Enantioselective Reductive Coupling of Oxabenzonorbornadienes with Vinyl Bromides

AbstractThe enantioselective reductive coupling of oxabenzonorbornadiene with vinyl bromide is developed with earth‐abundant nickel catalyst with copper as Lewis acid co‐catalyst. The asymmetric reductive coupling is applicable with a wide range of azabenzonorbornadienes and vinyl bromides under nickel/copper co‐catalytic system, affording the cis ring‐opening vinylation products in good yields with high optical purities. The present study has enabled straightforward stereoselective preparation of chiral 2‐vinyl‐tetrahydronaphthalens from vinyl halides.

Stereospecific Cu(I)-Catalyzed C-O Cross-Coupling Synthesis of Acyclic 1,2-Di- and Trisubstituted Vinylic Ethers from Alcohols and Vinylic Halides.

CuI and trans-N,N'-dimethylcyclohexyldiamine catalyze the single-step C-O bond cross-coupling between 1,2-di- and trisubstituted vinylic halides with functionalized alcohols, producing acyclic vinylic ethers. This stereospecific transformation selectively gives each of the (E)- and (Z)-vinylic ether products from the corresponding vinyl halide precursors. This method is compatible with carbohydrate-derived primary and secondary alcohols and several other functional groups. The conditions are mild enough to reliably generate vinylic allylic ethers without promoting Claisen rearrangements.

Regio- and Stereoselective Carbon-Boron Bond Formation via Heterogeneous Palladium-Catalyzed Hydroboration of Enallenes.

A highly efficient regio- and stereoselective heterogeneous palladium-catalyzed hydroboration reaction of enallenes was developed. Nanopalladium immobilized on microcrystalline cellulose (MCC) was successfully employed as an efficient catalyst for the enallene hydroboration reaction. The nanopalladium particles were shown by HAADF-STEM to have an average size of 2.4 nm. The cellulose-supported palladium catalyst exhibits high stability and provides vinyl boron products in good to high isolated yields (up to 90 %). The nanopalladium catalyst can be efficiently recycled and it was demonstrated that the catalyst can be used in 7 runs with a maintained high yield (>80 %). The vinylboron compounds prepared from enallenes are important synthetic intermediates that can be used in various organic synthetic transformations.

‘In heavy rotation’: uncovering the phonographic industry and the ‘NGOMA national label’ in socialist Mozambique (1978–1990)

ABSTRACT This article outlines the structure and editorial practices of the phonographic industry in postcolonial Mozambique during the so-called ‘socialist period’. It details the production phases, the associated companies and delves into the material conditions and aesthetic values that guided the phonograms published by NGOMA—dubbed as ‘the Mozambican national label’—and their relationship with state-defined cultural policy between 1978 (when production on this series commenced) and 1990 (when vinyl production officially ceased in the country). Several themes are explored, such as predominant topics of song lyrics, repertoires and artists, copyright, women artists, and the restrictions on music production during the civil war. After analysing the main musical trends and acknowledging noteworthy absences, I reflect on NGOMA’s efficiency in the nation-building process.

Potential of sediment bacterial communities from Manila Bay (Philippines) to degrade low-density polyethylene (LDPE).

The persistence of plastics and its effects in different environments where they accumulate, particularly in coastal areas, is of serious concern. These plastics exhibit signs of degradation, possibly mediated by microorganisms. In this study, we investigated the potential of sediment microbial communities from Manila Bay, Philippines, which has a severe plastics problem, to degrade low-density polyethylene (LDPE). Plastics in selected sites were quantified and sediment samples from sites with the lowest and highest plastic accumulation were collected. These sediments were then introduced and incubated with LDPE in vitro for a period of 91days. Fourier transform infrared spectroscopy detected the appearance of carbonyl and vinyl products on the plastic surface, indicating structural surface modifications attributed to polymer degradation. Communities attached to the plastics were profiled using high-throughput sequencing of the V4-V5 region of the 16S rRNA gene. Members of the phylum Proteobacteria dominated the plastic surface throughout the experiment. Several bacterial taxa associated with hydrocarbon degradation were also enriched, with some taxa positively correlating with the biodegradation indices, suggesting potential active roles in the partial biodegradation of plastics. Other taxa were also present, which might be consuming by-products or providing nourishment for other groups, indicating synergy in utilizing the plastic as the main carbon source and creation of a microenvironment within the plastics biofilm. This study showed that sediment microbes from Manila Bay may have naturally occurring microbial groups potentially capable of partially degrading plastics, supporting previous studies that the biodegradation potential for plastics is ubiquitously present in marine microbial assemblages.

Divergent regioselective Heck-type reaction of unactivated alkenes and N-fluoro-sulfonamides

The control of regioselectivity in Heck-type reaction of unactivated alkenes represents a longstanding challenge due to several detachable hydrogens in β–H elimination step, which generally afford either one specific regioisomer or a mixture. Herein, a copper-catalyzed intermolecular Heck-type reaction of unactivated alkenes and N-fluoro-sulfonamides with divergent regioselectivities is reported. The complete switch of regioselectivity mainly depends on the choice of different additives. Employment of alcohol solvent gives access to vinyl products, while the addition of carboxylate leads to the formation of allylic products. In addition, exclusion of these two promoting factors results in β-lactams via a C–N reductive elimination. This protocol shows a broad substrate scope for both alkenes and structurally diverse N-fluoro-sulfonamides, producing the corresponding products with excellent regio- and stereoselectivities. Further control experiments and DFT calculations provide in-depth insights into the reaction mechanism, highlighting the distinct effect of the additives on a bidentate auxiliary-stabilized Cu(III) intermediate.

Effects of consumer products chemicals ingredients and their mixtures on the estrogen receptor/androgen receptor transcriptional activation.

Unlike the environmental pollutants or industrial chemicals, the chemicals in consumer products may pose higher levels of risks, depending on how the chemicals are used in the products and how humans interact with the products. Recently, endocrine disrupting chemicals in cosmetics, personal care products, cleaners, sunscreens, and vinyl products were analytically quantified and many active chemicals including phthalates, parabens and bisphenols were detected. This indicates a wide range of exposures from common products. In this study, 35 chemicals known to be ingredients of consumer products were selected and screened for the transactivation of estrogen receptors and androgen receptors. From the results of individual chemicals, the activity of binary/ternary mixture prepared from the agonists for the ER transcription activity was measured, and compared to the predicted values obtained by the full logistic model. The measured and the predicted values were found to be very similar. This study may suggest that prediction of mixture activity by proper models would be one of the supportive tools for the risk assessment and sound regulation of chemical mixtures which have potential endocrine disrupting effects in consumer products.

A Study of Gen MZers’ Vinyl LP Collecting and Purchasing Experience

This study examines the vinyl collection craze among members of Gen MZ (20 to 30 year olds), with particular attention to their experiences, motivations, and interactions with other collectors and buyers. The Gen MZers who are driving the vinyl phenomenon did not grow up with vinyl records so why are they so enthusiastic about a retro media? We analyze research on cultural product consumption patterns and our field data and use grounded theory to apprehend the experiential world of Gen MZ vinyl record collectors through individual and focus group interviews and participant action research. Our goal is to gain insight into how their vinyl collecting, purchasing, and product creation activities affords them satisfaction, builds cultural capital, and contributes to shaping this moment in popular culture. In general, we found that the vinyl collecting craze among Gen MZers is driven by several factors, notably a strong sense of dissatisfaction with popular culture and the typically passive consumption of its products, coupled with the sense of fulfillment the collectors get from developing the specialized and exclusive knowledge that builds cultural capital. These factors intersect with certain distinctive personality traits of collectors, expressed in their impulse to establish themselves as uniquely discerning arbiters of musical taste and value, to produce a typically nostalgic trajectory through the world of collecting and consuming yesterday’s commercial audio technology.

The Analysis of Current Status of Vinyl Record Industry in Korea: Focusing on Expert Opinion on Planning, Producing, and Distributing Vinyl Records

본 연구의 목적은 LP 산업의 구조를 분석하여 해당 산업의 매력도를 이해하고 시사점을 도출하는 것에 있다. 선행연구는 급증한 LP 수요에 주목하며 소비자 관점에서 해당 소비와 LP 산업을 이해하였으나, 본 연구는 LP의 생산 및 유통의 주체에 초점을 맞추어 진행하였다. 본 논문은 LP 산업 내 현업종사자들과 심층면접 및 다양한 이차자료를 통해 자료를 수집하고, 이를 포터(1980/2008)의 5요인 이론(Five Forces model)으로 분석하였다. 분석결과, LP 산업의 매력도는 산업 내 경쟁 강도가 적정하고 구매자의 교섭력이 약하다는 측면에서는 긍정적이지만, 신규 진입자와 대체재의 위협 및 공급자의 교섭력이 강하다는 측면에서 부정적이다. 이는 LP 산업에 신규 진입하려는 기업들의 전략적 판단을 위한 기초자료로서의 의의가 있다.The purpose of this study is to understand the attractiveness of the vinyl record industry and derive implications by analyzing the structure of the industry. A few previous studies pay attention to the rapidly increasing demand for vinyl records, especially from a consumer point of view, and unlike the analysis of the consumption and vinyl record industry, this study focuses on the subjects of production and distribution of vinyl records. This paper collects data through in-depth interviews with experts in the vinyl record industry and various secondary data, which is analyzed by Porter(1980/2008) s Five Forces Model. According to the analysis, the attractiveness of the vinyl record industry is positive in terms of the appropriate competitive strength in the industry and weak bargaining power of buyers, but negative in terms of the strong bargaining power of new entrants and substitutes. The outcome of this research has significance as basic data implying that companies that are trying to enter the vinyl record industry need to make strategic decisions.

Vinyl Revival

Vinyl Revival

Further Chemistry of Ruthenium Alkenyl Acetylide Complexes: Routes to Allenylidene Complexes via a Series of Electrophilic Addition Reactions

The methyl substituents in the cationic allenylidene complexes trans-[Ru{C═C═C(Me)R}Cl(dppe)2]OTf ([1a–f]OTf) are readily deprotonated to give the corresponding alkenyl acetylide complexes trans-[Ru{C≡CC(═CH2)R}Cl(dppe)2] (3; R = Me (a), Ph (b), cC5H10 (c), 4-MeS-C6H4 (d), cC4H3S (e), cC5H4N (f)). Similar chemistry is also observed from [Ru{C═C═C(Me)Ph}(dppe)Cp*]PF6 ([2b]PF6) and [Ru{C═C═C(Me)(4-MeS-C6H4)}(dppe)Cp*]PF6([2b]PF6), chosen to broaden the reaction scope, giving [Ru{C≡CC(═CH2)Ph}(dppe)Cp*] (4b) and [Ru{C≡CC(═CH2)(4-MeS-C6H4)}(dppe)Cp*] (4d). In turn, reactions of 3b,d and 4b,d with the [BF4]− salt of the electrophilic tritylium [CPh3]+ cation give the functionalized allenylidene complexes trans-[Ru{C═C═C(CH2CPh3)R}Cl(dppe)2]BF4 ([5b,d]BF4) and [Ru{C═C═C(CH2CPh3)R}(dppe)Cp*]BF4 ([6b,d]BF4) formed by addition of the electrophile to the remote vinylic carbon (C(δ)). Although trans-[Ru{C═C═C(CH2CPh3)Me}Cl(dppe)2]BF4 ([5a]BF4) could not be successfully purified from reactions of 3a with [CPh3]BF4, deprotonation of the crude product gave the Zaitsev vinyl product trans-[Ru{C≡CC(═CHCPh3)Me}Cl(dppe)2] (7a) in good yield. The initial cycloheptatrienyl adducts formed from reactions of 3b,d and 4b,d with the tropylium salt [C7H7]BF4 undergo a ring-contraction process in chloroform solutions upon exposure to air, to give the styrene-like products trans-[Ru{C═C═C(R)C(H)═CHPh}Cl(dppe)2]BF4 ([10b,d]BF4) and [Ru{C═C═C(R)C(H)═CHPh}(dppe)Cp*]BF4 ([11b,d]BF4), through what is believed to be a radical mechanism mediated by triplet oxygen.

Modeling of batch production of high vinyl styrene/butadiene copolymers for high performance tires

AbstractMathematical modeling of batch production of high vinyl random styrene/butadiene copolymers in an industrial batch reactor was accomplished. Mass and energy balance equations were solved to model the nonisothermal anionic copolymerization of styrene/butadiene performed in an industrial batch reactor. The simulation model allows to predict the variation of the individual and global monomer conversion(s), temperature, pressure, and volume level of reactor with the time. Simulation model was used to determine the optimal polymerization conditions to maximize the production of a high vinyl random styrene/butadiene copolymer used in the manufacture of high performance tires.

Phthalates and Sex Steroid Hormones Among Men From NHANES, 2013-2016.

Phthalates are commonly found in commercial packaging, solvents, vinyl, and personal care products, and there is concern for potential endocrine-disrupting effects in males. The commonly used di-2-ethylhexyl phthalate (DEHP) has progressively been replaced by seldom studied compounds, such as bis-2-ethylhexyl terephthalate and 1,2-cyclohexane dicarboxylic acid di-isononyl ester (DINCH). To investigate the associations between the urinary phthalate metabolites and serum sex steroid hormone concentrations in a nationally representative sample of adult males. This was a cross-sectional analysis of data from the 2013-2016 National Health and Nutrition Examination Survey among 1420 male participants aged ≥20 years. Serum levels of total testosterone, estradiol, SHBG, and derived sex hormone measurements of free testosterone, bioavailable testosterone, and free androgen index were examined as log-transformed continuous variables. Phthalate metabolites were not statistically significantly associated with sex hormone concentrations among all men. However, associations varied by age. High molecular weight phthalates were associated with lower total, free, and bioavailable testosterone among men age ≥60. Specifically, each doubling of ΣDEHP was associated with 7.72% lower total testosterone among older men (95% confidence interval, -12.76% to -2.39%). Low molecular phthalates were associated with lower total, free, and bioavailable testosterone among men age 20 to 39 and ∑DINCH was associated with lower total testosterone among men age ≥40. Our results indicate that males may be vulnerable to different phthalate metabolites in age-specific ways. These results support further investigation into the endocrine-disrupting effects of phthalates.

Vinyl makers go sustainable

The Vinyl Sustainability Council has launched an initiative called +Vantage Vinyl to advance sustainability goals for resin suppliers, additive makers, material compounders, vinyl product makers, and others. The effort requires those who sign on to reduce landfill use and emissions and commit to health and safety improvements. So far, eight companies have signed on: Chemours, Formosa Plastics, Mexichem, Occidental Chemical, PolyOne, Shintech, Sika, and Westlake Chemical. The council is hoping to get more than 800 companies in the vinyl value chain, including siding manufacturers and pipe extruders, to sign on in the next 5 to 10 years, Ned Monroe, CEO of the Vinyl Institute, tells C&EN. The trade organization created the council and is helping to underwrite the new program. Program adherents will have to undergo annual third-party certification to verify that they are meeting goals and can use a +Vantage logo on their products. About 60% of pre- and

ПОЛІМЕР-ПОЛІМЕРНИЙ КОМПОЗИТ ОТРИМАНИЙ ШЛЯХОМ ПЕРЕРОБКИ ВІДХОДІВ ПВХ ЛІНОЛЕУМУ

Development of technology for the processing of mixed waste of vinyl flooring by their joint milling and plasticization. The determination of the MFI was carried out according to ISO 1133: 1997 on a capillary viscometer with a constant pressure and temperature (190 ± 0.5) ° C and a weight of 2.16 kg. The thermostability and melting temperature were determined on the Hipro RM 200C plastograph. Mechanical properties were determined on a breaking machine according to ASTM D638. Hardness - using a Shore D durometer, hydrostatic weighing density on an analytical balance RADWAG AS-X2. Equipment for milling and plasticization of a mixture of PVC / PET waste was selected. Qualitative milling of mixed waste is achieved by using a low speed rotary knife grinder with rotor speed of 300 rpm. The properties of the reinforced PVC were obtained. The strength of this film compared with the classic recipe is lower but when by using such materials in the composition it is possible to obtain a material with high physical and mechanical properties and achieve maximum non-waste production which will also have a positive effect on the economy of the enterprise. The technology for joint processing of mixed vinyl flooring waste was developed for the first time. The features of reinforcing PVC matrix with fibers of a PET was obtained at the receipt of films from mixed vinyl flooring waste. The developed technology allows to provide non-waste production of vinyl flooring at enterprises.

Characteristics of Particulate Matter and Volatile Organic Compound Emissions from the Combustion of Waste Vinyl

Vinyl samples were burned in a controlled environment to determine the characteristics of particulate matter (PM) and volatile organic compound (VOC) emissions during the combustion process. Open burning of plastic or vinyl products poses several environmental and health risks in developed and developing countries, due to the release of high concentrations of harmful pollutants. The production of fine and ultrafine particles was significant. At a heat flux of 25 kW/m2, the production of PM of 0.35 μm in size was highest at 63.0 μg/m3. In comparison, at fluxes of 35 and 50 kW/m2, the production of PM of 0.45 μm in size was highest with values of 67.8 and 87.7 μg/m3, respectively. Benzene, acetone, and other toxic compounds were also identified in the analyses.

Rapid Decontamination of Chemical Warfare Agent Simulant with Thermally Activated Porous Polymer Foams

Highly porous poly(dicyclopentadiene) (pDCPD) foam was synthesized via ring opening metathesis polymerization and high internal phase emulsion (HIPE) templating. Alkane and alkene moieties within the pDCPD foam oxidized slowly in air to form carbonyl, peroxy, and hydroxyl groups. Heating pDCPD to 85 °C in air accelerated the oxidation of pDCPD, producing reactive peroxy species at reduced time scales, compared to oxidation at room temperature. The oxidized pDCPD foams rapidly sequestered and decontaminated the toxic chemical warfare agent simulant, demeton-S via oxidation to vinyl, sulfoxide, and sulfone oxidation products. In addition, the porosity and high surface area of the pDCPD HIPE foams likely assists in the sequestration of demeton-S via capillary interaction. Collectively, these data demonstrate a new and highly tunable class of polymer materials capable of simultaneous sequestration and decontamination of toxic chemicals.