Template-Directed Polymerization of Binary Acrylate Monomers on Surface-Activated Lignin Nanoparticles in Toughening of Bio-Latex Films

Fabricating bio-latex colloids with core–shell nanostructure is an effective method for obtaining films with enhanced mechanical characteristics. Nano-sized lignin is rising as a class of sustainable nanomaterials that can be incorporated into latex colloids. Fundamental knowledge of the correlation between surface chemistry of lignin nanoparticles (LNPs) and integration efficiency in latex colloids and from it thermally processed latex films are scarce. Here, an approach to integrate self-assembled nanospheres of allylated lignin as the surface-activated cores in a seeded free-radical emulsion copolymerization of butyl acrylate and methyl methacrylate is proposed. The interfacial-modulating function on allylated LNPs regulates the emulsion polymerization and it successfully produces a multi-energy dissipative latex film structure containing a lignin-dominated core (16% dry weight basis). At an optimized allyl-terminated surface functionality of 1.04 mmol g⁻¹, the LNPs-integrated latex film exhibits extremely high toughness value above 57.7 MJ m⁻³. With multiple morphological and microstructural characterizations, the well-ordered packing of latex colloids under the nanoconfinement of LNPs in the latex films is revealed. It is concluded that the surface chemistry metrics of colloidal cores in terms of the abundance of polymerization-modulating anchors and their accessibility have a delicate control over the structural evolution of core–shell latex colloids.     

轻型防弹玻璃的结构研究

改变层合防弹玻璃的面板和背板材料及结构组合形式，并通过测量防弹性能和面密度,选出了轻型防弹玻璃的材料与结构。结果表明，以无机玻璃（G）作为面板材料，聚碳酸酯（PC）作为背板的表层材料，定向有机玻璃（DYB）作为中间过渡材料，即G／DYB／PC结构，具有优异的防弹性能，与传统防弹玻璃相比，可减重20％以上。同时还进一步研究了间隙装甲结构。     

丙烯酸类共聚物超吸水树脂的合成研究

用丙烯酸（AA）和丙烯酰胺（AM）作原料,以氢氧化铝为交联剂,过硫酸盐为引发剂,通过溶液聚合法,合成了高吸水性树脂聚（丙烯酸-丙烯酰胺）（P（AA-AM））共聚物。讨论了其在蒸馏水和NaCl水溶液中的吸液性能,考察了单体配比、丙烯酸中和度、交联剂用量、反应温度、引发剂用量等条件对树脂吸水性能的影响。结果表明,最佳合成丁艺为：n（AM）：n（AA）为O．3-0．4,AA的中和度为70％,过硫酸钾和单体的质量比为0．2％-0．3％,氢氧化铝和单体的质量比为0．03％-0．05％,聚合温度为55-60℃。测得的吸水倍率为1050g／g。     

New polymeric materials for paper and textiles conservation. II. Grafting polymerization of ethyl acrylate/methyl methacrylate copolymers onto linen and cotton

In the preservation of Cultural Heritage items, the use of polymeric materials for the consolidation and protection of artifacts with historical and artistic value is widely accepted, except for cellulose‐based materials, since here there are no suitable products and appropriate application techniques. Grafting polymerization of acrylic monomers onto cellulose chains represents an innovative method of restoration for both artificially and naturally aged textiles. In this article, some results concerning the grafting polymerization of ethyl acrylate/ethyl methacrylate 75/25 and ethyl acrylate/methyl methacrylate/trifluoroethyl methacrylate 73/24.5/2.5 polymers onto linen and cotton are reported. The effectiveness of grafting polymerization as a method for textiles conservation is discussed. The consolidating and protective effects were investigated by evaluating the mechanical properties and the wetting behavior of the grafted samples, and comparing them with the original and aged substrates. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 90–99, 2007     

ACR中壳层PMMA相对分子质量对PVC／ACR共混物性能的影响

采用种子乳液法制备了核壳型聚丙烯酸酯(ACR),并分别采用十二烷基硫醇和正辛基硫醇作为链转移剂对 ACR壳层的聚甲基丙烯酸甲酯(PMMA)进行相对分子质量调节,并用于PVC共混改性。黏度法对PMMA的相对分子质量测定表明,正辛基硫醇的相对分子质量调节能力较强。采用差示扫描量热分析测定PMMA的玻璃化转变温度(Tg),并对共混树脂进行动态力学性能测试。当ACR壳层PMMA平均相对分子质量低于12×104时,PVC/ACR 共混树脂的缺口冲击强度大大提高。与纯PVC相比,共混树脂的Tg均略有提高,其增量随ACR壳层PMMA平均相对分子质量的降低而减小。动态力学性能测试结果表明,ACR壳层聚合物平均相对分子质量越低,共混物分子链段运动活化能提高越少。     

Latex produced with carboxylic acid comonomer for waterborne coatings: Particle morphology variations with changing pH

Carboxylic acid comonomers are often added to latex formulations to improve colloidal stability and to help control the physical structure of composite (core-shell type) particles. We have performed a systematic study of the incorporation of methacrylic acid (MAA) within styrene/butyl acrylate copolymer seed latices, and determined the eventual effect on the morphology of the composite particles when using a second-stage monomer that is either polar (MMA) or nonpolar (BMA). These latices have been produced in batch and semibatch reactions in the pH range of 3–7. At low pH, the MAA groups are not ionized, but at the higher pH they may be nearly completely ionized. Here, we report that for batch reactions carried out within the above pH range, the latex particle morphologies of the PMMA second-stage systems change dramatically with increasing pH, while those for the PBMA system do not change at all. These results show that one cannot easily generalize the effect of acid comonomers on the morphology of composite latex particles, as this depends upon the choice of the copolymers in the latex and the process characteristics of the polymerization reaction. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.     

Antimicrobial finishing of acrilan fabrics with cetylpyridinium chloride: Affected properties and structures

Durable antimicrobial acrilan fabrics were prepared by using cetylpyridinium chloride (CPC) in a chemical finishing process. The CPC could form ionic interactions with anionic groups on acrilan fibers, which contribute to durable antimicrobial functions. Reaction conditions such as pH, temperature, and time of the chemical treatment affected exhaustion of CPC and antimicrobial properties. However, the pH conditions of the finishing bath also impacted mechanical properties and color of the fabrics, particularly under alkaline conditions. Although a more alkaline condition is preferred for durable antimicrobial functions, high pH reduces tensile strength and results in yellowing of acrilan fibers. The yellowing of the acrilan fibers is caused by the hydrolysis of acrylonitrle groups and induced formation of conjugated C?N systems in the polymers. The conjugated systems were characterized by FTIR. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1227–1236, 2005     

CR系列稀土增深剂在涤,腈染色中的应用

本文介绍了以多组分单一稀土为原料.生产的CR系列增深剂在涤、腈染色工艺中的应用.该产品除具备氯化稀土的特点外,同时具有稳定.可靠、一致,宜于大批量生产应用.