SMRs

A significant revision to the SMR scheme was introduced in 1991 in response to consumer desire for greater consistency in natural mbber (13). Other producing countries have similar specification schemes (14), as does the International Standards Organization (ISO) (15). An example of the specifications for TSR is given in Table 1 for the present Standard Malaysian scheme. Except for SMR 5, rheograph and cure test data (delta torque, optimum cure time, and scorch) are provided. 

Table 1. Standard Malaysian Rubber (SMR) Specifications Scheme ...

Two subgrades of SMR 5 are SMR 5RSS and SMR 5ADS, which are prepared by direct baling of ribbed smoked sheet and air-dried sheet (ADS), respectively. 

TSR 5. Within the Malaysian scheme SMR 5 is restricted to mbber derived from sheet material prepared by conventional processes, ie, ribbed smoked sheet (RSS), air-dried sheet (ADS), and unsmoked sheet (USS) and presented in small bale form. Other countries may source different raw materials, eg, Indonesia produces SIR 5 from thin latex coagulum (14). SMR 5 prepared by pressing dry-sheet material into standard bales must be identified by the type of sheet material, eg, SMR 5RSS, on the test certificate as well as on the wrapping. 

This is an activator-starved formulation and so is highly sensitive to the presence of nonmbbers that are capable of activating or accelerating vulcanization, and Table 2 illustrates the cure behavior of different grades of SMR (28). Cup lump grades show the highest state of cure and fastest rate of cure, whereas the stabilized grade, SMR CV, shows the lowest state of cure and slowest cure rate. 

Table 2. Cure Characteristics of SMR Grades Mixed to the ACSl Formulation...

Moment of Inertia. Moment of inertia, I, is a property of the mass distribution of a body around an axis (I = Smr ). Its SI unit is kg-m. ... 

Currently, five different molecular classes of mdr efflux pumps are known [5], While pumps of the the ATP-binding cassette (ABC) transporter superfamily are driven by ATP hydrolysis, the other four superfamilies called resistance-nodulation-division (RND), major facilitator superfamily (MFS), multidrug and toxic compound extrusion (MATE), and small multidrag resistance transporter (SMR) are driven by the proton-motive force across the cytoplasmic membrane. Usually a single pump protein is located within the cytoplasmic membrane. However, the RND-type pumps which are restricted to Gram-negative bacteria consist of two additional components, a periplasmic membrane fusion protein (MFP) which connects the efflux pump to an outer... 

Smr (QacC) Quartemary ammonium compounds S. aureus Plasmid... 

NR SMR 10 Carbon black N-220 Silica, Perkasil KS 408 Zinc oxide Stearic acid Aromatic oil Resin Cumarone Resin Colophony Coupling agent, TESPT TMQ 6PPD... 

---