The combination of a neodymium borohydride, Nd(BH4)3(THF)3 (1) or Cp*Nd(BH4)2(THF)x (2), with MgBuEt (BEM), affords an efficient and highly selective (up to 96.7% 1,4-trans) catalyst for butadiene polymerization. In the presence of excesses of Mg co-catalyst, polymer chain transfer takes place between neodymium and magnesium, and significant amounts of 1,2-units are observed. When considered fo...

with respect to the physical and mechanical limited qualities of bitumen, it benefits from certain specificability in application and its life service. polymers as the most important modifiers of bitumen are applied to it in order to improve its functional efficiency. among various polymers, styrene-butadiene- styrene (sbs) is the best modifier of the bitumen. in this work, sbs polymer as one o...

The control of cell proliferation by gastrin has been investigated in a rat pancreatic tumour cell line, AR4-2J. Exogenous gastrin, 10-12 to 10-8 M, stimulated cell growth of thymidine-synchronised AR4-2J cells cultured over 48 h in serum-free medium. Cell lysates of AR4-2J cells contained an average of 4.5 and 3.5 pg gastrin per 106 cells, when grown in serum-supplemented or serum-free media, ...

polymer application for the improvement and modification of the bitumen used in roads surfaces has expanded in recent decades. the roads engineers and constructors, therefore, have used the modified bitumen in asphalts helping in this way to increase roads and pavements service life and improving the durability of the roads and asphalts. the bitumen used in asphalt mixture constitutes only a lo...

Design and Testing of Digitally Manufactured Para n Acrylonitrile-Butadiene-Styrene Hybrid Rocket Motors

Kompleks ortamlarda asphalt kaplamaların performansını garanti etmek için styrene- butadiene- styrene (SBS), butadiene rubber (SBR), crumb (CR), and polyphosphoric acid (PPA) gibi bazı malzemeler bitüm modifikasyonunda kullanılmıştır. Modifikasyon yöntemleri sırasında, geleneksel asfalt bağlayıcıyı geliştirmek veya desteklemek alternatif katkılar Modifiye üretilmesinde en çok kullanılan polimer...

This presentation provides a brief overview of the production and use of 1,3-butadiene in the United States. Starting as a coproduct of ethylene, the 1,3-butadiene monomer is extracted and purified, then transferred to consumers. Major uses of 1,3-butadiene include the manufacture of styrene-butadiene rubber, polybutadiene rubber, and adiponitrile.

Residual levels of 14 volatile substances, including 1,3-butadiene, acrylonitrile, benzene, ethylbenzene, and styrene, in 30 kitchen utensils made from acrylonitrile-butadiene-styrene resin (ABS) and acrylonitrile-styrene resin (AS) such as slicers, picks, cups, and lunch boxes in Japan were simultaneously determined using headspace gas chromatography/mass spectroscopy (HS-GC/MS). The maximum r...