Polymer Tech

NR How to improve Tensile strength in Natural rubber ? In Natural rubber based compounds avoid using peptizer such as  dibenzamido-diphenyl disulfide or pentachlorothiophenol (PCTP)  because it may reduce the ultimate tensile strength of the compound. EPDM: 1.Use semicrystalline EPDM grades (with higher ethylene content) to impart higher ultimate tensile strength. 2.Increasing the molecular weight of EPDM can result in an improved ultimate tensile strength

Standard Test method for Rubber Hose Scope: These method describe the procedure for inspection and test of all types and construction of rubber hose ASTM D 380-94

Rubber Interview Questions Laboratory Questions Define Polymerization? The process of formation of polymers from respective monomers is termed as polymerization Why do Polymers have different properties? They have different chemical compositions (different monomer units), different structures, different ways of being fabricated, etc. What is TGA  Thermogravimetric Analysis.it is a test procedure used to determine the thermal stability or composition of a material. Two modes are possible; determining the change of weight of a specimen while changing temperature at a given rate of the change of weight of a specimen with time at a fixed temperature. Why does butyl rubber exhibit high gas permeability? Beacause the densely packed structure of the linear hydrocarbon chains makes butyl rubber exhibit unusually low gas permeability. What is the Monomer composition of butyl rubber? Butyl rubber or isobutylene-isoprene rubber (IIR) is formed by the copolymerization...

B Backrind :  A molding defect in which the rubber adjacent to the parting line shrinks below the surface of the molded product, with the parting line often being ragged and torn. 파팅 라인에 인접한 고무가 성형 제품의 표면 아래로 수축하여 파팅 라인이 종종 깎여서 찢어지는 성형 결함. Banbury mixer:  A special type of internal mixer used to blend fillers and other ingredients with an elastomer. 충전재 및 기타 성분을 엘라스토머와 혼합하는 데 사용되는 특수 유형의 내부 혼합기. Bank : the reservoir of material at the opening between rolls of a mill or calendar Band: (1) A strip of rubber from a previous batch left  running round the front roll of an open mill to facilitate loading of the next batch. (2) An assembly of plies of rubberised cord fabric used in ‘building’ or making; the casing of a pneumatic tyre Batch:  The product of one mixing operation. Back-Up-Ring :  (Anti extrusion device) A ring of relatively hard and tough material, pl...