N,N′‐Pentamethylenethiuram disulfide‐ and N,N′‐pentamethylenethiuram hexasulfide‐accelerated sulfur vulcanization. I. Interaction of curatives in the absence of rubber

Reyneke-Barnard, C. P.; Gradwell, M. H. S.; McGill, W. J.

doi:10.1002/1097-4628(20000919)77:12<2718::aid-app200>3.3.co;2-5

Cited by 3 publications

(21 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Materials and experimental procedures were described in earlier articles in this series 1, 3. Compounds, prepared on a Barbender Plasticorder, were vulcanized in a DSC at a programmed heating rate or isothermally in a press at 150°C and TME mixtures were vulcanized in evacuated sealed tubes at 150°C.…”

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…N,N ′‐dipentamethylenethiuram disulfide (CPTD) readily reacts with sulfur to form N,N ′‐dipentamethylenethiuram polysulfides (CPTP), the reaction being unaffected by the addition of ZnO 1. CPTD is thermally unstable and at vulcanization temperatures readily decomposes to N,N ′‐dipentamethylenethiourea (CPTU) 1, 2. Piperidene, which catalyzes the degradation process, is generated by the decomposition of small amounts of pentamethylenedithiocarbamic acid (Hpmtc), formed in the slow dehydrogenation reaction between sulfenyl radicals and hydrogen in methylene groups on the undissociated disulfide 2.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

N,N?-Pentamethylenethiuram disulfide andN,N?-pentamethylenethiuram hexasulfide accelerated sulfur vulcanization. IV. Vulcanization of polyisoprene and 2,3-dimethyl-2-butene in the presence of ZNO

Reyneke-Barnard

Gradwell

McGill

2000

J. Appl. Polym. Sci.

Self Cite

View full text Add to dashboard Cite

Polyisoprene and model compound, 2,3‐dimethyl‐2‐butene, were vulcanized with N,N′‐dipentamethylenethiuram disulfide (CPTD), CPTD/sulfur and N,N′‐dipentamethylenethiuram hexasulfide (CPTP6) in the presence of ZnO and zinc (bispentamethylenedithiocarbamate) (ZPD), and residual extractable curatives and reaction intermediates analyzed by HPLC at various stages of the reaction. CPTD and ZnO do not react at vulcanization temperatures and, as in zinc‐free systems, the reaction is initiated by accelerator polysulfides that lead to the formation of thiuram terminated pendent groups. Pentamethylenedithiocarbamic acid, liberated in the process, is trapped by ZnO as ZPD. Crosslinking is more rapid than in the absence of ZnO. ZPD catalyzes the crosslinking of thiuram pendent groups, and high crosslink densities are achieved because the ZPD catalyzed crosslinking of thiuram crosslink pendent groups is more efficient than when thiuram pendent groups crosslink, mainly via a reaction with thiol pendent groups, as is suggested in the absence of zinc. When free sulfur is available in the system, ZPD acts as an accelerator in its own right. Thiuram pendent groups were not detected in ZPD/sulfur formulations with model compounds, but their formation or the formation of thiol pendent groups, either of which may form via sulfurated ZPD, cannot be excluded. ZPD promoted the rapid crosslinking of such pendent groups. Overall, the reaction mechanism with zinc‐containing formulations is similar to those for the corresponding TMTD systems. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1112–1120, 2000

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

N,N?-Pentamethylenethiuram disulfide andN,N?-pentamethylenethiuram hexasulfide accelerated sulfur vulcanization. IV. Vulcanization of polyisoprene and 2,3-dimethyl-2-butene in the presence of ZNO

Reyneke-Barnard

Gradwell

McGill

2000

J. Appl. Polym. Sci.

Self Cite

View full text Add to dashboard Cite

show abstract

“…An interesting fact is under conditions (toluene/Gibbs) for similar formulations of NR [6] , the rubber extract usually produces an eluted deposit, in higher RF and yellow color, which is essentially the plasticizer. Thus, the analysis of the 3°RF deposition in toluene was made to characterize the naphthenic plasticizer in the formulation, succeeding in the applied methodology ( Figure 5), since that the separated product spectrum (3°Rf) showed the same absorptions of referred additive.…”

Section: Nr(cbs)mentioning

confidence: 99%

“…In terms of thermal stability, their higher bond strength gives more stability than the carbon/sulfur/carbon bond and gives good properties for aging resistance [5] . Study of sulfur vulcanization has been mentioned in the literature [6] . TMTD, among others accelerator polysulfides such as N,N-pentamethylenethiuram disulfide (CPTD) were employed and it was concluded that CPTD and its polysulfides are thermally less stable than is TMTD.…”

Section: Introductionmentioning

confidence: 99%

Characterization of additives in NR formulations by TLC-IR (UATR)

et al. 2018

View full text Add to dashboard Cite

ObstractIt is a well-established fact that rubber accelerator is essential to provide solution in different sectors. However, there is a reversal process which can reduce the material performance. Sulfur accelerators donors and organic peroxides have been presented as a solution to the problem. The methodology development that can separate or characterize those components is a challenge and still allows gaps, explained by the application of conventional technique to reach this goal. This study aimed at contributing to the use of off-line coupling of thin layer chromatography (TLC)/infrared spectroscopy (IR) by Universal Attenuated Total Reflection (UATR) for analysis of N-cyclohexyl-2-benzotiazolsulfenamide (CBS), tetraethylthiuram disulfide (TMTD) and dicumyl peroxide (DCP), in natural poly-cis-isoprene (NR) formulations, containing naphthenic oil. The best results were obtained for the plasticizer and DCP, in formulations that had a greater proportion of these compounds. The separation of CBS and TMTD was made with less effectiveness, due to bands overlapping.

show abstract

N,N?-Pentamethylenethiuram disulfide andN,N?-pentamethylenethiuram hexasulfide accelerated sulfur vulcanization. III. Vulcanization of polyisoprene and 2,3-dimethyl-2-butene in the absence of ZnO

Reyneke-Barnard

Gradwell

McGill

2000

J. Appl. Polym. Sci.

Self Cite

View full text Add to dashboard Cite

Polyisoprene and model compound, 2,3‐dimethyl‐2‐butene, were vulcanized with N,N′‐dipentamethylenethiuram disulfide (CPTD), CPTD/sulfur and N,N′‐dipentamethylenethiuram hexasulfide (CPTP6) in the absence of ZnO and residual extractable curatives and reaction intermediates analyzed by HPLC at various stages of the reaction. Accelerator polysulfides, required for the formation of accelerator‐terminated polysulfidic pendent groups, form rapidly, or are present from the outset in the case of CPTP6. Model compounds confirm the formation of thiuram‐terminated polysulfidic pendent groups as intermediates in the vulcanization process. Removal of pentamethylenedithiocarbamic acid (Hpmtc) from the system during heating delays the onset of vulcanization and leads to very low crosslink densities. Rubbers heated under vacuum can subsequently be crosslinked by the addition of zinc stearate, pointing to the presence in the compound of thiuram‐terminated pendent groups. However, such pendent groups do not readily crosslink on their own, and hydrogen‐terminated polysulfidic pendent groups, formed by the reaction of sulfurated Hpmtc with the polymer, are suggested to be involved in the crosslink formation. N,N′‐Pentamethylenethiurea forms in the vulcanizate, but is not as product of crosslinking reactions, rather of CPTD degradation. The data are discussed with respect to mechanisms proposed in the literature for crosslinking, and it is concluded that the data support recently formulated mechanisms in which crosslinking involves reaction between thiuram and thiol‐terminated pendent groups, with Hmptc playing and essential role in the overall process. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1100–1111, 2000

show abstract

N,N′‐Pentamethylenethiuram disulfide‐ and N,N′‐pentamethylenethiuram hexasulfide‐accelerated sulfur vulcanization. I. Interaction of curatives in the absence of rubber

Cited by 3 publications

References 0 publications

N,N?-Pentamethylenethiuram disulfide andN,N?-pentamethylenethiuram hexasulfide accelerated sulfur vulcanization. IV. Vulcanization of polyisoprene and 2,3-dimethyl-2-butene in the presence of ZNO

N,N?-Pentamethylenethiuram disulfide andN,N?-pentamethylenethiuram hexasulfide accelerated sulfur vulcanization. IV. Vulcanization of polyisoprene and 2,3-dimethyl-2-butene in the presence of ZNO

Characterization of additives in NR formulations by TLC-IR (UATR)

N,N?-Pentamethylenethiuram disulfide andN,N?-pentamethylenethiuram hexasulfide accelerated sulfur vulcanization. III. Vulcanization of polyisoprene and 2,3-dimethyl-2-butene in the absence of ZnO

Contact Info

Product

Resources

About