Fully renewable limonene‐derived polycarbonate as a high‐performance alkyd resin

Limonene‐derived polycarbonate‐based alkyd resins (ARs) have been prepared by copolymerization of limonene dioxide with CO₂, catalysed by a β‐diiminate zinc–bis(trimethylsilyl)amido complex, and subsequent chemical modification with soybean oil fatty acids using triphenylethylphosphonium bromide as the catalyst. This quantitative partial modification was realized via epoxy–carboxylic acid chemistry, affording ARs with higher oil lengths, lower polydispersities and higher glass transition temperatures (T_g) in comparison to a conventional polyester AR based on phthalic acid, multifunctional polyol pentaerythritol and soybean fatty acid. The novel limonene polycarbonate AR and the conventional polyester AR were evaluated as coatings and both the physical drying (without the presence of the oxidative drying accelerator Borchi® Oxy Coat) and chemical curing (with Borchi® Oxy Coat) processes of these coatings were monitored by measuring the König hardness and complex modulus development with time. A better performance was obtained for the alkyd paint containing polycarbonates modified with fatty acids (FA‐PCs), which showed a faster chemical drying, a higher König hardness and a higher T_g in coating evaluation, demonstrating that the fully renewable FA‐PCs are promising resins for alkyd paint applications. © 2019 Society of Chemical Industry     

Blends of Bio-Based Poly(Limonene Carbonate) with Commodity Polymers

In this study, blends of the bio-based poly(limonene carbonate) (PLimC) with different commodity polymers are investigated in order to explore the potential of PLimC toward generating more sustainable polymer materials by reducing the amount of petro- or food-based polymers. PLimC is employed as minority component in the blends. Next to the morphology and thermal properties of the blends the impact of PLimC on the mechanical properties of the matrix polymers is studied. The interplay of incompatibility and zero-shear melt viscosity contrast determines the blend morphology, leading for all blends to a dispersed droplet morphology for PLimC. Blends with polymers of similar structure to PLimC (i.e., aliphatic/aromatic polyester) show the best performance with respect to mechanical properties, whereas blends with polystyrene or poly(methyl methacrylate) are too brittle and polyamide 12 blends show very low elongations at break. In blends with Ecoflex (poly(butylene adipate-co-terephthalate)) and Arnitel EM400 (copoly(ether ester)) with poly(butylene terephthalate) hard and polytetrahydrofuran soft segments) a threefold increase in E-modulus can be achieved, while keeping the elongation at break at reasonable high values of ≈200%, making these blends highly interesting for applications.     

用废EPS制备低毒清香型胶粘剂

以橙皮为原料提取精油并对其作GC分析,以精油、乙酸乙酯及丙酮作混合溶剂,用废聚苯乙烯泡沫塑料(EPS)制备胶粘剂;对制备胶粘剂条件作了正交分析,比较了该胶与市售白乳胶的性能差异。结果表明,橙皮提取的精油中柠檬烯质量分数高达96%;V乙酸乙酯/V丙酮/V精油=5/2/3的混合溶剂,对废EPS的溶解力最强。制备胶粘剂最优条件为:乳化剂0.75g,MAA3.0g,酚醛树脂2.0g,BPO0.30g。制备的低毒清香型胶粘剂,剥离强度为0.35kN/m。     

Essential oil yield and composition of Pistacia vera ‘Kerman’ fruits,peduncles and leaves grown in California

BACKGROUND: Pistacia vera ‘Kerman’ is the predominant pistachio nut cultivar in the United States (California), the world's second largest producer. Despite several reports on the essential oil (EO) content in the genus Pistacia, data on ‘Kerman’ are limited. The EO content and volatile organic compound (VOC) emissions of tree nut orchards are of current interest to researchers investigating insect pests and the potential role of EO and VOCs as semiochemicals. To establish a basis for the VOC output of pistachios, the EO content of fruits, peduncles, and leaves was analyzed. RESULTS: Evaluated plant parts contained limonene as the primary EO component, followed by α‐terpinolene. Peduncles were unique in containing relatively high levels of α‐thujene. The results were reproducible between two different geographical locations. In situ solid phase microextraction (SPME) studies demonstrated the volatile emission was representative of the EO composition. CONCLUSION: This is the first report detailing the content and distribution of EO and the unique limonene‐dominant profile for this Pistacia vera cultivar which may influence pistachio insect pest semiochemical research. Copyright © 2010 Society of Chemical Industry     

从废弃的柑橘皮中提取d-柠檬烯的工艺研究

从废弃的柑橘皮中提取柠檬烯的提取工艺进行了研究,实验采用较环保的水蒸气蒸馏法提取柑橘皮中柠檬烯,并对其提取工艺、条件进行研究。从而确定工艺条件。对分离得到的产品通过测定折射率、比旋光度和紫外扫描谱图等对其进行了鉴定,证明提取产物为d-柠檬烯。     

Oxidation of d-Limonene in Presence of Low Density Polyethylene

Headspace oxygen contents of sodium citrate-water buffers containing d-limonene with and without low density polyethylene (LDPE) were measured on a weekly basis for 10 wk. d-Limonene was readily sorbed into LDPE. Results indicated first order kinetics for limonene oxidation. GC/MS analyses determined production of limonene oxidation end-products, including d-carvone, carveol, limonene oxide, perrilaldehyde and linalool, as well as α-terpineol, a hydrolysis product. Headspace oxygen contents of the d-limonene/buffer (control) samples were lower thau that of the d-limonene/buffer/LDPE samples, suggesting a higher oxidation rate in the control than in LDPE. Oxidation rate constants and half-lives were 5.9 × 10^-3 log(%O₂) wk^-1, t_1/2= 116 wk for control and 1.2 × 10^-3 log(%O₂) wk^-1, t_1/2= 580 wk for LDPE samples, respectively.     

Quantitative Comparative Analysis of the Bio-Active and Toxic Constituents of Leaves and Spikes of Schizonepeta tenuifolia at Different Harvesting Times

A GC-MS-Selected Ion Monitoring (SIM) detection method was developed for simultaneous determination of four monoterpenes: (-)-menthone, (+)-pulegone, (-)-limonene and (+)-menthofuran as the main bio-active and toxic constituents, and four other main compounds in the volatile oils of Schizonepeta tenuifolia (ST) leaves and spikes at different harvesting times. The results showed that the method was simple, sensitive and reproducible, and that harvesting time was a possible key factor in influencing the quality of ST leaves, but not its spikes. The research might be helpful for determining the harvesting time of ST samples and establishing a validated method for the quality control of ST volatile oil and other relative products.     

橘皮柠檬烯的研究与应用进展

综述了柑橘皮中的柠檬烯在制备和应用方面的研究进展。介绍了柑橘皮柠檬烯曲提取分离技术、分析方法、生理与生物活性及其应用的研究进展,并对柠檬烯的应用前景进行了展望。