Modeling of Compression Curves of Flexible Polyurethane Foam with Variable Density, Chemical Formulations and Strain Rates

Glycols in Polyurethane Foam Formulations with a Starch–Oil Composite

A dry starch–oil composite was blended with each of three glycols; ethylene, polyethylene, and propylene, and then reacted with isocyanate to produce polyurethane foams. The liquid glycols permitted the dry composite to blend well with the other ingredients in the foam formulations. Infrared spectra confirmed the presence of urethane structures in the composite–glycol foams. Polyethylene glycol...

Waste Minimization Strategy: Flexible Polyurethane Foam Manufacture

Methylene chloride and CFCs are used as auxiliary blowing agents in the manufacture of flexible polyurethanefoams and are promptly emitted during the manufacturing processes.The concentrationof the auxiliary blowing agent are quite low due to the accepted practice of using large volumes of air to lower the ambient concentration of toxic isocyanates (a key chemical in the urethane reaction seque...

5. Exploring Urea Phase Connectivity in Molded Flexible Polyurethane Foam Formulations Using LiBr as a Probe

extraction and acetylation of purified trypsin from bovin pancreas and study of some its physico-chemical properties

آنزیم تریپسین در شرایط قلیایی ناپایدار می باشد .و فعالیت پروتئولیتیکی تریپسین منجربه خود هضمی آن در جایگاههای خاصی می گردد. بنابر این آنزیمی با ناپایداری بالا محسوب میگردد. در سالهای اخیر موفق شدند که با ایجاد تغیرات شیمیایی با اضافه کردن فلزات خاص ، کلسیم و یا عمل استیلاسیون منجر به افزایش پایداری آنزیم تریپسین گردند. مطالعات در حال حاضر نشان می دهد که تریپسین استیله شده فعالیت آنزیمی خود را ...

Novel Gelling Catalyst for Non-Emission Flexible Polyurethane Foam

Flexible and semi-rigid polyurethane foams have been widely used in automotive interior parts, residential upholstered furniture and bedding. In these, as well as other end use industries, a reduction of Volatile Organic Compounds (VOCs) emissions from polyurethane foams continues to be an important issue [1, 2]. To address this challenge, reactive amine catalysts, which have an active hydrogen...

a comparison of teachers and supervisors, with respect to teacher efficacy and reflection

supervisors play an undeniable role in training teachers, before starting their professional experience by preparing them, at the initial years of their teaching by checking their work within the proper framework, and later on during their teaching by assessing their progress. but surprisingly, exploring their attributes, professional demands, and qualifications has remained a neglected theme i...