Post‐polymerization modification of bio‐based polymers: maximizing the high functionality of polymers derived from biomass

The renaissance of the bio‐based chemical industry over the last 20 years has seen an ever growing interest in the synthesis of new bio‐based polymers. The building blocks of these new polymers, so called platform molecules, contain significantly more chemical functionality than their petrochemical counterparts (such as ethene, propene and para‐xylene). As a result bio‐based polymers often contain greater residual chemical functionality in their chains, with groups such as alkenes and hydroxyls commonly observed. These functional groups can act as sites for post‐polymerization modification (PPM), thus further extending the range of applications for bio‐based polymers by tailoring the polymers' final properties. This mini‐review highlights some of the most recent and compelling examples of how to make use of bio‐based polymers with residual functional groups for PPM. It also looks at how the emerging interdisciplinary field of enzymatic polymer synthesis allows for increased functionality in polymers by avoiding side‐reactions as a result of milder reaction conditions, and additionally offers an alternative means of polymer surface modification. © 2018 Society of Chemical Industry     

Enhancement of the water repellency durability of the fabrics treated by fluorinated nanocopolymer emulsions

The fluorinated copolymer emulsions containing different monomers with the reactive groups were successfully prepared at our lab, using emulsion polymerization technique. The water repellency and the durability for the fabrics treated by fluorinated water repellents after 30 and 50 washes were measured and compared. Actually, the combination of the comonomers containing blocked isocyanate or other reactive groups after copolymerization would increase the durability of the water repellency. In addition, the blocked isocyanate crosslinking agent (Jintexguard FCN) does, indeed, substantially increase the durability also. It clearly indicates that the copolymer emulsion prepared by the reaction of fluorinated acrylate, cyclohexyl methacrylate, and 3‐chloro‐2‐hydroxy‐propyl methacrylate(Topolene M) with monomers containing blocked isocyanate group(Jintexan BIA) showed very good durability. More importantly, the combination of this copolymer and Jintexguard FCN will significantly provide excellent water repellency and durability after 50 washes. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2451–2457, 2007     

Preparation of an adhesive in emulsion for maxillofacial prosthetic

Maxillofacial prostheses is a dental medicine specialty aimed at restoring anatomical facial defects caused by cancer, trauma or congenital malformations through an artificial device, which is commonly attached to the skin with the help of an adhesive. The purpose of our research was to develop a pressure-sensitive adhesive (PSA) based on acrylic monomers, characterizing and determining its drying kinetics, that is to say the time it takes to lose 50 to 90% of its moisture. The adhesive synthesis was realized by means of emulsion polymerization; the composition of formulations was: (AA-MMA-EA) and (AA-MMA-2EHA) with different molar ratios. The formulation based on (AA-MMA-2EHA) with 50 w% of solids, presented good adhesive properties such as tack, bond strength, and short drying time. We propose this formulation as a PSA, because it offers an alternative for systemically compromised patients, by less irritation compared to organic solvent-based adhesives.     

含氟复鞣剂研究进展

含氟复鞣剂可以赋予皮革良好的手感、优异的透气性、抗水抗油性、抗污性等性能。阐述了合成含氟复鞣剂用含氟单体和非氟共聚单体的选择及其合成工艺 ,介绍了含氟复鞣剂的研究进展 ,指出含氟复鞣剂今后将会向着高质量、多功能化方向发展     

On the Catalytic Activity of Sn Monomers and Dimers at Graphene Edges and the Synchronized Edge Dependence of Diffusing Atoms in Sn Dimers

In this study, in situ transmission electron microscopy is performed to study the interaction between single (monomer) and paired (dimer) Sn atoms at graphene edges. The results reveal that a single Sn atom can catalyze both the growth and etching of graphene by the addition and removal of C atoms respectively. Additionally, the frequencies of the energetically favorable configurations of an Sn atom at a graphene edge, calculated using density functional theory calculations, are compared with experimental observations and are found to be in good agreement. The remarkable dynamic processes of binary atoms (dimers) are also investigated and is the first such study to the best of the knowledge. Dimer diffusion along the graphene edges depends on the graphene edge termination. Atom pairs (dimers) involving an armchair configuration tend to diffuse with a synchronized shuffling (step-wise shift) action, while dimer diffusion at zigzag edge terminations show a strong propensity to collapse the dimer with each atom diffusing in opposite directions (monomer formation). Moreover, the data reveals the role of C feedstock availability on the choice a single Sn atom makes in terms of graphene growth or etching. This study advances the understanding single atom catalytic activity at graphene edges.     

A comprehensive evaluation of vat-photopolymerization resins and alumina slurries for ceramic stereolithography

Ceramic slurries play an essential role in the fabrication of complex ceramic parts in ceramic stereolithography (CSL), in which photosensitive monomer is the focus. In this study, the comprehensive properties of commonly used monomers were quantitatively studied by a new evaluation system. As a result, ACMO, PONPGDA and EOTMPTA were selected as the final three monomers with better properties. On this basis, an optimal combination of the above monomers with the best comprehensive performance was obtained by blending them at a ratio of 60:60:40. Next, the influence of different resins on the properties of alumina slurries was investigated. It was found that using the mixture of the above three monomers, an excellent as-prepared slurry with low viscosity, small shrinkage and good photo-curable ability was obtained.     

基于复合功能单体噻菌灵印迹传感器的制备及应用

目的：快速检测食品中噻菌灵残留量。方法：通过紫外光谱法筛选邻氨基苯酚和邻苯二胺作为复合功能单体,采用电化学分析法研究了聚合条件、洗脱条件,对传感器性能进行了评价,建立了食品中噻菌灵残留的快速检测方法。结果：在最佳条件下,该印迹传感器对噻菌灵及其结构类似物具有特异吸附性能,且对噻菌灵的选择性最强;该方法的线性范围在1×10^-8～1×10^-4 mol/L,检出限为3.3×10^-9 mol/L,样品加标平均回收率为88.16%～100.73%,相对标准偏差（RSD）≤2.63%。结论：该传感器具有优异的印迹效应以及良好的选择性、重现性与稳定性,可用于食品中噻菌灵残留的快速检测。     

乳聚丁苯橡胶国内外生产技术及进展

论述了乳聚丁苯橡胶国内和国外生产技术及进展,分析了国内和国外ESBR生产工艺技术特点,技术进步主要围绕优化工艺控制,提高聚合转化率,完善凝聚技术,研制高效引发剂和新型乳化剂,开发不含有亚硝酸胺的环保型ESBR。     

交联单体在丙烯酸弹性乳液中的应用

用不同的交联单体做交联剂，采用合适的工艺条件，合成了两种丙烯酸弹性乳液。讨论了两种弹性乳液所成膜的性能差别，及不同乳化剂对乳液性能的影响。     

Synthesis and polymerization of anthracene‐based itaconimides

Two new anthracene‐based itaconimides, ie N‐(1‐ and 2‐anthryl) itaconimides, were synthesized by the reaction of aromatic amines with itaconic anhydride, followed by itaconamic acid imidization. The same reaction failed in the case of anthracene‐ring substitution at the position 9′. Radical and thermal polymerization of N‐(1‐ and 2‐anthryl) itaconimides led to polymers with anthracene pendant groups. No self‐polymerization by Diels–Alder cycloaddition of the itaconic function (dienophile) and anthracene nucleus (diene) was observed, as is the case for N‐(anthryl) maleimides and citraconimides. Copyright © 2004 Society of Chemical Industry