Studies in antioxidants. Part IV: Bridged bis(thiosemicarbazone) as melt stabiliser for unstabilised isotactic polypropylene

Raja, A.; Pendyala, V. N. S.; Xavier, S. F.; Shah, A. C.; Nair, K. B.

doi:10.1016/0142-9418(95)00036-4

Cited by 2 publications

(2 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The above increase in tensile strength retention values may be compared with those given in the literature17, 18 for recycled blends by using commercially available stabilizers such as Irganox 1010, Irgafos 168, and Tinuvin 770 DFD. The hydroperoxide decomposer TPP and chain slipping agent combination was found to be either the same or a little better.…”

Section: Resultsmentioning

confidence: 95%

Effect of hydroperoxide decomposer and slipping agent on recycling of polypropylene

Agrawal

Utreja

2004

J of Applied Polymer Sci

View full text Add to dashboard Cite

Polypropylene (PP) recycling has always been challenging because the polymer is highly susceptible to thermooxidative degradation during extrusion. Recycled (degraded) PP is normally blended with virgin PP to achieve reasonable mechanical properties after reprocessing operations. However, impurities present in recycled PP tend to degrade even the virgin PP in this process. In this study, standard recycled PP was produced in a laboratory by repeated extrusion and pelletization operations of virgin PP. This material was blended with virgin PP in a ratio from 3 : 7 to 7 : 3. An attempt was made to stabilize the recycled blend by adding a peroxide decomposer (triphenylphosphite, TPP) and a slipping agent (zinc stearate) in contrast to radical scavengers normally used in reprocessing. It was found that by using 0.3-0.5 wt % of TPP and 2 wt % of zinc stearate, this degradation could be effectively attested. Compared to the tensile strength retention of 68% (based on strength of pure virgin PP) of a 60 : 40 (recycled : virgin) PP blend without any stabilizer, a value of 77% was obtained for the same blend with the above-mentioned stabilizers. This stabilization effect was attributed to decomposition of unstable hydroperoxides to stable compounds in the recycled materials by TPP, and lower generation of new radicals in the presence of zinc stearate.

show abstract

Section: Resultsmentioning

confidence: 95%

Effect of hydroperoxide decomposer and slipping agent on recycling of polypropylene

Agrawal

Utreja

2004

J of Applied Polymer Sci

View full text Add to dashboard Cite

show abstract

“…In our earlier studies,6–9 we modified the structure of BHT by introducing a bulky group at a para position to the OH group. Novel antioxidants, based on hindered phenol in combination with acid hydrazides and thiosemicarbazones, were synthesized.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and characterization of hindered‐phenol‐containing amine moieties as antioxidants for polypropylene copolymers

Desai

Pendyala

Xavier

et al. 2003

J of Applied Polymer Sci

View full text Add to dashboard Cite

(4-Ethylphenyl)-3,5-ditertiarybutyl-4-hydroxybenzylamine, 1-phenyl-4-(3,5-ditertiarybutyl-4-hydroxybenzyl)piperazine, and 1-(3,5-ditertiarybutyl-4-hydroxybenzyl)piperidine were synthesized and characterized, and their performance in polypropylene copolymer (PPCP) was tested by multiple extrusions in a Brabender plasticorder. The thermooxidative stability of PPCP was assessed by the measurement of oxidative induction time at 200 Ϯ 1°C, and the thermal stability was assessed by observation of the change in the melt flow rate. A comparative study of the synthesized antioxidants with the commercially available antioxidant 2,6-ditertiarybutyl-4-methylphenol was made. The presence of phenolic and amino groups influenced the performance of the antioxidants. The performance of the antioxidants influenced the thermal stability of the PPCP.

show abstract

Studies in antioxidants. Part IV: Bridged bis(thiosemicarbazone) as melt stabiliser for unstabilised isotactic polypropylene

Cited by 2 publications

References 5 publications

Effect of hydroperoxide decomposer and slipping agent on recycling of polypropylene

Effect of hydroperoxide decomposer and slipping agent on recycling of polypropylene

Synthesis and characterization of hindered‐phenol‐containing amine moieties as antioxidants for polypropylene copolymers

Contact Info

Product

Resources

About