排序方式: 共有58条查询结果,搜索用时 15 毫秒
31.
《Composite Interfaces》2013,20(8-9):717-736
The development of a novel reactive unsaturated interfacial modifier for filled (magnesium hydroxide, aluminium hydroxide and calcium carbonate) polyolefins is reviewed. Initial work explored maleimide functional candidate molecules including 1,3-phenylene dimaleimide (1,3-PDM) and a range of linear alkyl dimaleimides. Most of the dimaleimides were very effective interfacial modifiers in polypropylene and poly(ethylene-co-vinylacetate) (18% w/w vinylacetate) based composites. However, the dimaleimides caused the composites to have a distinct pink/brown colouration apart from when the maleimide groups were spaced by a C12 alkyl chain. The problem with colour and high effective dosage prompted a switch to unsaturated carboxylic acid based systems. The performance of a range of unsaturated carboxylic acids and the hexafunctional monomer trimethylolpropane triacrylate are reviewed, together with a novel oligomeric unsaturated carboxylic acid (OUCA) based system developed by the Noveon Division of Lubrizol Limited. The data obtained from this series of interfacial modifiers, and adsorption studies on 1,3-PDM and OUCA, afforded some insight into the competing factors (such as the strength of adsorption versus ability to form a polymerised interfacial layer and the ability to react with matrix chains) that significantly affect the coupling performance of interfacial modifiers. 相似文献
32.
33.
34.
The synthesis of N, N-bis-carboxymethylaminoacetomethionine was described. The acid dissociation constants and the formation constants of its indium (III) chelates at 25`C and \m\=0.1(KNO3) were determined (pka1=2.452, pka2=3.320, pka3=6.799; log KInL=8.90, log KInLi=6.47, log βInLi=15.37) by pH titration method. The hydrolysis constant of the chelate at 30`C was also given. The optimal pH for the formation of normal chelate was calculated to be about 4.8. In addition, the chelate species and coordinated atoms of the ligand were briefly discussed. 相似文献
35.
《Composite Interfaces》2013,20(7):489-513
Interfacial adhesion of sisal/coir hybrid fibre reinforced natural rubber (NR) composites has been characterized by restricted equilibrium swelling technique with special reference to the effects of fibre loading, orientation and bonding agent. The swelling parameters of NR composites with and without bonding agent were evaluated with three aromatic solvents, namely; benzene, toluene and xylene, by a sorption gravimetric method. As fibre content and penetrant size increase, the solvent uptake has been found to decrease due to the increased hindrance and good fibre–rubber interaction. The bonding agent added mixes showed enhanced restriction to swelling and it is seen that the ratio of change in volume fraction of rubber before and after swelling to the volume fraction of rubber before swelling (V 0 – V r/V 0) is lower for bonding agent added composites, when compared to an unbonded one. The anisotropic swelling studies were carried out to analyse the extent of fibre alignment and fibre–matrix interaction. In strongly bonded composites, the swelling has been mainly observed to take place in the thickness direction, as attested by optical photographs. The rubber–fibre interaction has also been examined by Lorenz–Parks and Kraus equations. 相似文献
36.
《Composite Interfaces》2013,20(8):701-714
To investigate the influence of the grafting density and the molecular structure of block copolymers on the interfacial assembly behavior and interfacial shear strength, macromolecular coupling agents, hydroxyl-terminated poly(n-butyl acrylate-b-styrene) (HO-P(BA-b-S)) were synthesized by atom transfer radical polymerization, and then chemically anchored on the glass fiber surfaces to form a well-defined monolayer. The phase separation and 'hemispherical' domain morphologies of diblock copolymer brushes at the polystyrene/glass fiber interface were observed. The interfacial assembly morphology differs with changes in the grafting density of diblock copolymers. When the grafting density is greatest, the highest height difference of the hemispherical domain and the largest surface roughness are achieved, as well as the best interface shear strength. It was also found that the copolymer brush with a PBA block of the polymerization degree (Xn) about 77 is the optimal option for the interfacial adhesion of PS/GF composites. Thus, the grafting density and molecular structure of diblock copolymers determines the interfacial assembly behavior of copolymer brushes, and therefore the interfacial shear strength. 相似文献
37.
本文报道了AOT-C6H12-H2O反相胶束介质中α-萘乙酸(α-NAA)敏化双乙酰(BIAC)的室温磷光。详细讨论了琥珀酸二(2-乙基己基)酯磺酸钠(AOT)浓度和水泡大小(W值)对敏化磷光的影响。吸收、发光性质和微粘度性质的实验表明AOT浓度对敏化磷光强度的影响由敏化磷光寿命、能量转移效率和Poisson分布决定; 一定范围内, 随着水浓度增大, 由于粘度下降和内腔半径增大作用的相互抵销, 水泡大小仅有微弱影响。当W([H2O]/[AOT])大于20后, 内腔半径增大起主要作用, 敏化磷光强度快速下降。与普通SDS胶束相比, 磷光强度约增强13倍, 检出限约下降一个数量级。建立了灵敏的测定α-萘乙酸和双乙酰的敏化室温磷光法, 检出限分别达2.0×10^-^8mol.dm^-^3(α-NAA)和8.5×10^-^9mol.dm^-^3(BIAC)。 相似文献
38.
40.