"Structural changes of moisture crosslinked ethylene-vinyltrimethoxysilane copolymer upon thermal ageing"@en . "2011-10-07+02:00"^^ . "Obadal, Martin" . "Central and Eastern European Committee for Thermal Analysis and Calorimetry" . . . "978-606-11-1893-9" . . . "Pastorek, Miroslav" . "Structural changes of moisture crosslinked ethylene-vinyltrimethoxysilane copolymer upon thermal ageing" . . "232735" . "RIV/70883521:28610/11:43867327!RIV12-MSM-28610___" . . . "[0AEC4A6EC591]" . . "1"^^ . "Structural changes of moisture crosslinked ethylene-vinyltrimethoxysilane copolymer upon thermal ageing" . "S" . "Structural changes of moisture crosslinked ethylene-vinyltrimethoxysilane copolymer upon thermal ageing"@en . "Etylene-vinyl trimethoxysilane copolymer (EVS) is a type of polyethelene-like material capable to crosslink under moisture even at the room temperature. Hence, the crosslinking proceeds in solid state as well as in the melt opposite to the peroxide crosslinked polyethylene which evolves the crosslinks only above decomposition temperature of peroxide, i.e. in the melt. Furthermore, the crosslinking through silane groups does not involve a step (especially in copolymer) of free radicals creation and thus undesirable side-reactions are restricted to minimum. This work investigates behavior and property evolution of silane crosslinked polyethylene (commercially supplied EVS copolymer) upon thermal ageing in the oven. Copolymer was first mixed with catalytic masterbatch and then extruded on tapes. Subsequently, the specimens were crosslinked in water bath and after that the thermal ageing at two different temperatures takes place. The changes in polymer during ageing were followed by differential scanning calorimetry, infrared spectroscopy and standard tensile testing. It was found that two parallel processes influence the final properties depending on ambient conditions: further crosslinking reactions and improvement of crystalline order. These two processes play different role either the ageing proceed below melting temperature or above melting temperature. Furthermore, improvement of crystalline order has greater influence on mechanical properties then further crosslinking reactions. Ageing below melting temperature involves rearrangement of chains without significant changes in crystalline order whereas ageing above melting temperature exhibits significant changes due to remelting and homogenizing of material and thus different crystallization of more crosslinked chains takes place."@en . . . "Etylene-vinyl trimethoxysilane copolymer (EVS) is a type of polyethelene-like material capable to crosslink under moisture even at the room temperature. Hence, the crosslinking proceeds in solid state as well as in the melt opposite to the peroxide crosslinked polyethylene which evolves the crosslinks only above decomposition temperature of peroxide, i.e. in the melt. Furthermore, the crosslinking through silane groups does not involve a step (especially in copolymer) of free radicals creation and thus undesirable side-reactions are restricted to minimum. This work investigates behavior and property evolution of silane crosslinked polyethylene (commercially supplied EVS copolymer) upon thermal ageing in the oven. Copolymer was first mixed with catalytic masterbatch and then extruded on tapes. Subsequently, the specimens were crosslinked in water bath and after that the thermal ageing at two different temperatures takes place. The changes in polymer during ageing were followed by differential scanning calorimetry, infrared spectroscopy and standard tensile testing. It was found that two parallel processes influence the final properties depending on ambient conditions: further crosslinking reactions and improvement of crystalline order. These two processes play different role either the ageing proceed below melting temperature or above melting temperature. Furthermore, improvement of crystalline order has greater influence on mechanical properties then further crosslinking reactions. Ageing below melting temperature involves rearrangement of chains without significant changes in crystalline order whereas ageing above melting temperature exhibits significant changes due to remelting and homogenizing of material and thus different crystallization of more crosslinked chains takes place." . "28610" . "4"^^ . "Navr\u00E1tilov\u00E1, Jana" . . . "2"^^ . "Craiova" . . "Craiova" . . . . "RIV/70883521:28610/11:43867327" . . "moisture crosslinking, EVS copolymer, thermal ageing"@en . "\u010Cerm\u00E1k, Roman" . "Book of Abstracts of the 1st Central and Eastern European Conference on Thermal Analysis and Calorimetry (CEEC-TAC1)" .