Chemistry of dicumyl peroxide‐induced crosslinking of linear polyethylene

Hulse, G. E.; Kersting, R.; Warfel, David R.

doi:10.1002/pol.1981.170190305

Cited by 58 publications

(48 citation statements)

References 15 publications

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“…Unsaturation was observed in the 1 H spectrum of the residue, suggesting the participation of radicals that originated from dodecene (produced by the disproportionation of two dodecane radicals). Qualitatively, this result was similar to that observed by Hulse et al 15 …”

Section: Dodecanesupporting

confidence: 82%

“…They found that ϳ50 -60% of the formed n-pentadecane radicals were involved in dimer formation, as observed by liquid chromatography. In a similar study, Hulse et al 15 used n-tetradecane to elucidate the crosslinking mechanism in the peroxide modification of PE. They found that ϳ44% of the formed n-tetradecane radicals were involved in dimer formation.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Dual monomer grafting of styrene and maleic anhydride onto model hydrocarbon substrates

Clark

Baker

Russell

et al. 2000

J. Polym. Sci. A Polym. Chem.

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Section: Dodecanesupporting

confidence: 82%

Section: Introductionmentioning

confidence: 99%

Dual monomer grafting of styrene and maleic anhydride onto model hydrocarbon substrates

Clark

Baker

Russell

et al. 2000

J. Polym. Sci. A Polym. Chem.

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“…Cross‐linked polyethylene blends were prepared by curing with DCP . To this end, EOC, LDPE, and HDPE were blended in a twin‐screw micro‐extruder (DSM Research) at 160 °C for 5 min.…”

Section: Methodsmentioning

confidence: 99%

Tunable Multiple‐Shape Memory Polyethylene Blends

Hoeher

Raidt

Krumm

et al. 2013

Macro Chemistry & Physics

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Shape memory polymers (SMPs) are an important class of smart materials. Usually, these polymers can be switched between two shapes. Recently, the possibility of switching more than two shapes was introduced for SMPs with relatively low strain storage capability. In this work, a lightly cross-linked polyethylene blend comprising 80 wt% EOC, 15 wt% LDPE, and 5 wt% HDPE is prepared in order to obtain a tunable multiple-shape memory polymer with high strain storage capacity. It is found that depending on the programming procedure, this SMP obtains a dual-, triple-, or quadruple-shape memory effect, with well-defi ned intermediate temporary shapes (retraction < 0.5% K −1 ) over a signifi cantly broad temperature range (up to 30 K), large storable strains (up to 1700%), and nearly full recovery of all shapes ( > 98.9%). transition range. [14][15][16][17][18] For instance, Xie [ 19 ] obtained a tunable multiple-shape memory for PFSA (perfl uorosulfonic acid ionomer), which possesses a broad glass transition from 55 to 130 ° C, by correlating certain temporary shapes to different temperatures within its glass transition range. Kolesov and Radusch [ 20 ] showed a triple-shape memory for cross-linked polyethylene blends of HDPE and two different ethylene-1-octene copolymers (EOC), by correlating different temporary shapes to distinct temperatures within a broad melting range. With this system, they were able to store strains of up to 100% with an intermediate shape at 44%. In general, multiple-shape memory polymers store strains of up to 240%, which limit the relative retraction response. We have recently found that the stored strain of PE-SMPs can be greatly enhanced by lowering the degree of cross-linking in a way that the resulting network is at the borderline between thermoplastics and elastomers. [ 21 ] In the present manuscript, this concept is extended to polyethylene blends in order to obtain a tunable multiple-shape memory polymer with large strain storage capability. Experimental Section MaterialsHigh density polyethylene (HDPE) (Lupolen 6021D, M w = 220 000 g mol −1 , PDI = 10, 0.5 branches per 1000 C atoms) [ 22 ]

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“…In an effort directed to solve some of these questions, there have been studies in the past dealing with fractions of linear PE, substances consisting in low molecular weight analogues to polyethylene, and other model polymers. [4][5][6][17][18][19] In this paper, we present some of the latest results found in our work on irradiation and peroxide crosslinking of hydrogenated polybutadienes (HPB). These polymers, which can be considered ethylene-butene random copolymers, were obtained from the catalytic hydrogenation of monodisperse linear polybutadienes produced by anionic polymerization.…”

Section: Introductionmentioning

confidence: 98%

Modification of Model Ethylene‐Butene Copolymers Using Gamma Radiation and an Organic Peroxide

Andreucetti¹,

Pérez

Failla

et al. 2006

Macromolecular Symposia

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Summary: Well-characterized linear ethylene-butene copolymers with polydispersities lower than 1.1 were modified using gamma radiation and an organic peroxide with the purpose of assessing the relative importance and form of evolution of the chain-linking processes with these two methods. The copolymers used in this work were obtained by hydrogenation of polybutadienes, which were synthesized by anionic polymerization of butadiene. Part of these materials were irradiated by gamma rays in a 60 Co radiation facility and the rest was modified with 2,5-dimethyl-2,5 di(terbutyl peroxy)-hexane in the molten state. As expected, the critical radiation dose and the critical concentration of peroxide required for the onset of gelation decreases with average molecular weight of the original copolymer. Although, the chain-linking reactions govern the modification process, there is a fraction of molecular chains that suffers scission. The measurable fraction of molecules having molecular weights lower than the original quasi-monodisperse copolymers is, for both processes, about 5% of the total modified polymer. On the post-gel region, the gel amount increases continuously with the radiation dose and the peroxide concentration added to the copolymers. For the radiation modified polymers, the calculation of the evolution of the molecular weights assuming ideal network forming conditions agreed very well with the experiments both, before and after the gel point. This is not accomplished when the modification process is done with the use of peroxides. Also, the results obtained from the peroxide modification processes at low relative concentrations with respect to the critical one for gelation show that the evolution of the structural modification evolves at a considerable lower rate than that observed in the radiation results.

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Chemistry of dicumyl peroxide‐induced crosslinking of linear polyethylene

Cited by 58 publications

References 15 publications

Dual monomer grafting of styrene and maleic anhydride onto model hydrocarbon substrates

Dual monomer grafting of styrene and maleic anhydride onto model hydrocarbon substrates

Tunable Multiple‐Shape Memory Polyethylene Blends

Modification of Model Ethylene‐Butene Copolymers Using Gamma Radiation and an Organic Peroxide

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