JOURNAL OF POLYMER RESEARCH
·
2025
·Vol. 32
·期 3
·1-10
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IF 2.8
Feng Yanqing,Guo Penghui,Ding Wei,Jin Yushun,Liu Ruofan,Wu Yibo
The use of renewable bio-based monomers to prepare polyisobutylene-based polymers can not only reduce the dependence on petroleum resources but also promote the green transformation of the cationic polymerization industry. Herein, 2-chloro-2,4,4-trimethylpentane (TMPCl) was synthesized as the main initiator and then cooperated with co-initiator TiCl 4 to construct a cationic initiation system, which was successfully used in preparing poly(isobutylene- co - β -myrcene). The effects of co-initiator concentration, monomer concentration and monomer feed ratio on the copolymerization of isobutylene (IB) and β -myrcene were investigated. The results showed that the molecular weight (M n ) first increased and then decreased with elevating the concentration of TiCl 4 . When the monomer concentration was 15 wt% and the monomer feed ratio (mole ratio between IB and β -myrcene) was 98:2, an IB- co - β -myrcene random copolymer with a molecular weight of 7.3 × 10 3 g/mol and a lower T g (-67.97 ℃) was obtained. According to the 1 H NMR analysis of the polymer structure and terminal groups, it was suggested that IB and β -myrcene mainly formed the copolymer with 1,4 structural unit under this initiation system, thus the cationic polymerization mechanism of IB and β -myrcene was further proposed. This work can provide basic data and theoretical guidance for the manufacture of greener polyisobutylene-based polymers in the future.
研究领域:
材料科学
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 10
·2363
·
IF 4.2
Tao Li,Mingzu Zhang,Jinlin He,Peihong Ni
Graft copolymers have unique application scenarios in the field of high-performance thermoplastic elastomers, resins and rubbers. β-myrcene (My) is a biomass monomer derived from renewable plant resources, and its homopolymer has a low glass transition temperature and high elasticity. In this work, a series of tapered copolymers P(My-co-AMS)k(k = 1, 2, 3) were first synthesized in cyclohexane by one-pot anionic polymerization of My and α-methyl styrene (AMS) using sec-BuLi as the initiator. PAMS chain would fracture when heated at high temperature and could endow the copolymer with thermal degradation property. The effect of the incorporation of AMS unit on the thermal stability and glass transition temperature of polymyrcene main chain was studied. Subsequently, the double bonds in the linear copolymers were partially epoxidized and hydroxylated into hydroxyl groups to obtain hydroxylated copolymer, which was finally used to initiate the ring-opening polymerization (ROP) of ε-caprolactone (ε-CL) to synthesize the graft copolymer with PCL as the side chain. All these copolymers before and after modifications were characterized by proton nuclear magnetic resonance (1H NMR), gel permeation chromatography (GPC), thermogravimetry analysis (TGA), and differential scanning calorimeter (DSC).
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INORGANIC CHEMISTRY
·
2021
·
IF 5.165
Fen You,Jingjing Zhai,Yat-Ming So,Xiaochao Shi
A convenient synthetic route has been developed for preparing the novel rigid 4,5-(PR2)2–2,7,9,9-tetramethylacridane-based pincer ligands (acri-RPNP; R = iPr and Ph), and the first rare-earth (Ln = Y, Lu) alkyl complexes bearing the acri-RPNP ligands were synthesized by a salt metathesis reaction (for the isopropyl-substituent acri-iPrPNP complexes, 1-Ln) or direct alkylation (for the phenyl-substituent acri-PhPNP complexes, 2-Ln). For both 1-Ln and 2-Ln, the NMR spectroscopy and X-ray diffraction study confirmed the successful coordination of the acri-RPNP ligand to the central metal ion in a tridentate manner via the two phosphine and the nitrogen donors. In contrast to 1-Ln that are solvent-free complexes, the metal centers in 2-Ln are each coordinated with one tetrahydrofuran molecule. Upon activation by [Ph3C][B(C6F5)4], 1-Y and 2-Lu could catalyze the living polymerization of isoprene and β-myrcene with high catalytic activity and high cis-1,4-selectivity (up to 92.3% for isoprene and 98.5% for β-myrcene). Moreover, the 1-Y/[Ph3C][B(C6F5)4] catalytic system also could promote the polymerization of butadiene and its copolymerization with isoprene to produce copolymers with high cis-1,4-selectivity and narrow polydispersity.
研究领域:
化学
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材料科学
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催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
AQUATIC TOXICOLOGY
·
2020
·
IF 4.346
Naicheng Li,Mengmeng Tong,Patricia M. Glibert
Ulva prolifera is a macroalgae that forms massive blooms, negatively impacting natural communities, aquaculture operations and recreation. The effects of the natural products, eugenol, β-myrcene, citral and nonanoic acid on the growth rate, antioxidative defense system and photosynthesis of Ulva prolifera were investigated as a possible control strategy for this harmful taxon. Negative effects on growth were observed with all four chemicals, due to the excessive production of reactive oxygen species and oxidative damage to the thalli. However, the response of U. prolifera under the four chemicals stress was different at the cellular level. β-myrcene, the most effective compound in terms of growth inhibition, induced oxidative stress as shown by the damage of total antioxidant capacity (T-AOC) and the downregulation of the glutathione-ascorbate (GSH-ASA) cycle which inhibited the antioxidative system. This chemical also inhibited photosynthesis and photoprotection mechanisms in U. prolifera , resulting in growth limitation. In contrast, U. prolifera was less affected by the second tested chemical, eugenol, and showed no significant change on photosynthetic efficiency in the presence of the chemical. The inhibition effects of the third and fourth tested chemicals, nonanoic acid and citralon, on growth and on the antioxidant defense system in U. prolifera were inferior. These results provide a potential avenue for controlling green tides in the future.
研究领域:
海洋生物学
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生态毒理学
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植物学
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环境科学
✓ 已验证
DOI
PubMed
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2025
·
IF 6.2
Manmin Zhang,Yan Huang,Hongzi Lai,Hongming Zhang,Guanle Li,Xiaoxiao Dai,Qihe Yang,Cuihua Liu,Lubin Zhang,Xiaonan Zhang
Landmark fruit Citrus maxima (Burm.) is highly productive, but by-products can cause environmental pollution. This study simulates the storage conditions of Citrus maxima at various stages after harvest and models the nutrient content and changes in different by-products. An organic acid deep eutectic solvent (OADES) was configured using six organic acids as hydrogen bond donor (HBD) in combination with choline chloride (ChCl); and the yields of essential oils and pectin were optimized using response surface methodology. The study showed that the OADES configured with oxalic acid as the HBD had the highest extraction rate. The results of electronic nose (E-nose) combined with GC-MS showed that the volatile odors of the essential oils were mainly from β-Myrcene (38 %), D-Limonene (37 %), and β-Pinene (4.3 %). When the raw materials were stored for more than 30 days, the yields of essential oils were decreased by 27.68 %, and the composition was mainly a decrease of 4.3 % in the proportion of sesquiterpenes and an increase of 7 % in alcohols. After 60 days of storage, the yield decreased by 27.68 %, the composition was mainly mono sesquiterpenoids decreased by 21.8 % and alcohols increased by 20.8 %. In addition, throughout the storage period (0–60 d), the pectin yield increased and then decreased, with a denser structure and more thermally stable and methylated pectin compared to the pre-extraction grapefruit peel. The research results not only provide new methods for green and energy-saving extraction technologies, but also offer valuable insights for optimizing the storage and reproduction practices in the citrus industry.
研究领域:
植物学
·
食品化学
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绿色化学
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分析化学
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农业科学
✓ 已验证
产品关联
DOI
高影响因子
Foods
·
2024
·Vol. 13
·期 17
·2653
·
IF 4.7
Zhiwei Hou,Ziyue Chen,Le Li,Hongping Chen,Huiyuan Zhang,Sitong Liu,Ran Zhang,Qiyue Song,Yuxuan Chen,Zhucheng Su,Liying Xu
Scented green tea (Camellia sinensis) is a type of reprocessed green tea produced by scenting with flowers. To investigate the differences in the volatiles of scented green tea processed with four different flowers (Jasminum sambac,Osmanthus fragrans,Michelia alba, andRosa rugosa), gas chromatography–ion mobility spectrometry (GC–IMS) and gas chromatography–mass spectrometry (GC–MS) were employed to detect and identify the volatile compounds in the four types of scented teas. GC–IMS and GC–MS identified 108 and 101 volatile compounds, respectively. The key characteristic volatile compounds, namely indole, linalool,β-myrcene, benzyl acetate, and ethyl benzoate (jasmine tea); cedrol, (E)-β-ionone,γ-decalactone, and dihydro-β-ionol (osmanthus tea); geraniol, phenylethyl alcohol, jasmone, methyl jasmonate, hexadecanoic acid, 4-ethyl-benzaldehyde, 2-methylbutyl hexanoate, and indole (michelia tea); and 3,5-dimethoxytoluene, (E)-β-ionone, and 2-methylbutyl hexanoate (rose tea), were identified through chemometric analysis combined with relative odor activity values (ROAVs) and sensory evaluation. This study provides new insights into the formation of aroma molecular fingerprints during green tea scenting with flowers, providing theoretical guidance for infusing distinct aroma characteristics into green tea during scented tea processing.
研究领域:
食品科学
·
分析化学
·
农学
·
植物科学
✓ 已验证
DOI
PubMed
高影响因子
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