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Get technical solutions to your PP Clarifiers issues!
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Description |
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The most efficient clarifying agents are sorbitol dibenzyl acetals. The specific
chemical structure is shown on figure 9 below.
Figure 1 : Sorbitol dibenzyl acetal structure
1st Generation : (DBS or 1,2,3,4 - dibenzylidene sorbitol)
DBS is a white powder melting at 230°C. Optimum effects are observed with
random PP copolymers particularly for transparency. Organoleptic properties
of final product stays at very good level. However, introduction of DBS may
create plate out problems.
2nd Generation : (MDBS or 1,2,3,4 - di-para-methylbenzylidene sorbitol)
MDBS melts at 265°C and is much more effective than DBS. Incorporation
of this product in iPP requires precautions like soft conditions (220-230°C,
low shear), addition of acid neutralizers (starates, ethoxylated amines...)
and anhydrous storage to avoid acidic hydrolysis (extrusion under nitrogen
and efficient stabilisation are also recommended to minimize degradation).
2nd Generation Clarifiers exibit poor organoleptic properties.
3rd Generation : (DMDBS or 1,2,3,4 - di-meta, para-methylbenzylidene sorbitol)
DMDBS is more efficient than MDBS and provides improved organoleptic properties over previous generation.
 To get expert advice on your problems with polypropylene clarification, contact us via TechDirect . |
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