Toughening composites for liquid composite moulding

Available from British Library Document Supply Centre-DSC:DXN046892 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Hemp fibre as alternative to glass fibre in sheet moulding compound. Part 2 : impact properties

This paper describes the results of falling weight impact tests on natural fibre reinforced polyester composites fabricated using a conventional sheet moulding compound (SMC) process. The influence of hemp fibre and CaCO3 filler content on the penetration energy of hemp fibre reinforced sheet moulding compound (H-SMC) is reported and compared with glass fibre reinforced sheet moulding compound (G-SMC). To evaluate the influence of fibre/matrix interfacial adhesion on the impact behaviour of these H-SMCs, the hemp fibres were treated with alkaline and silane treatments, as well as a combination of these treatments. A simple mechanistic model is proposed for these natural fibre composites and is used to obtain more insight into the impact behaviour of the composites as well as to provide guidelines to compare the experimental data with theory.Peer reviewe

Synthesis and characterization of amphiphilic triblock copolymers including -alanine/-methyl--alanine and ethylene glycol by "click" chemistry

WOS: 000460703600029Terminally azide poly--alanine (PBA-Az) was directly obtained by hydrogen transfer polymerization of acrylamide in the presence of sodium azide as an initiator. However, terminally azide poly(-methyl -alanine) (PmBA-Az) was synthesized by the reaction between terminally bromo poly(-methyl -alanine) and sodium azide. Dipropargyllated polyethylene glycol (PEG-di-Pr) was synthesized by using the reaction of PEGs with different molecular weights and propargyl bromide. Synthesis of poly(-alanine-b-ethylene glycol-b--alanine) and poly(-methyl -alanine-b-ethylene glycol-b--methyl -alanine) amphiphilic ABA triblock copolymers was achieved via click chemistry of PBA-Az or PmBA-Az and PEG-di-Pr with different molecular weight. Click reaction parameters such as concentration and time were assessed. Macromonomers and the amphiphilic triblock copolymers were characterized by using H-1-NMR, FT-IR, MALDI-MS, TGA, and elemental analysis techniques. The multi-instruments studies of the obtained amphiphilic triblock copolymers reveal that the copolymers easily formed as a result of click chemistry