Silicone rɔba a ɛyɛ mmerɛw wɔ digrii 250 mu no nyɛ nea ɛda adi "normal", na mmom nea efi ne onyin kwan mu ba wɔ tebea pɔtee bi mu.
Mpɛn pii no, silicone rɔba agye din wɔ ɔhyew a ɛko tia no ho, na bere tenten{0}}bere mu som hyew taa fi -60℃kosi 200-230℃. Sɛ ɔhyew no kɔ soro kodu soro kodu digrii 250 anaa nea ɛboro saa a, onyin ho nhyehyɛe atitiriw pii bɛkɔ soro ntɛmntɛm, na awiei koraa no, ɛbɛma wɔayɛ mmerɛw. Nea ɛde ntini a ɛyɛ mmerɛw no ba titiriw ne nnuru titiriw a ɛwɔ nkɔnsɔnkɔnsɔn titiriw ne afã akuw a ɛwɔ silicone rɔba polymer no mu a wontumi nsakra no mu. Nea edidi so yi yɛ akwan titiriw pii a ɛma ɛyɛ mmerɛw .
1. Side Group Oxidation (Afiri Titiriw) Adeyɛ: Silicone rɔba a ɛtaa ba ne methyl vinyl silicone rɔba. Wɔ ɔhyew a ɛkɔ soro mu no, oxygen a ɛwɔ mframa mu no bɛtow ahyɛ methyl akuw ({2}}CH3) so wɔ polymers no nkɔnsɔnkɔnsɔn a ɛwɔ nkyɛn no so. Nnuruyɛ mu adeyɛ: Methyl kuw no yɛ oxidized, edi kan yɛ hydroxyl kuw (-OH), a ebia afei ɛbɛfa-abɔ anaasɛ ɛbɛma oxide afoforo aba. Saa adeyɛ yi yɛ crosslinking points foforo (oxidative crosslinking) wɔ molecule chains ntam.
Nea efi mu ba: Bere a crosslinking points foforo dodow kɔ so yɛ kɛse no, polymer network no yɛ den dodo na ɛyɛ den. Nneɛma no hwere ne ntini a ɛyɛ den no, ɛyɛ den, na awiei koraa no, sɛ wɔde adwennwen nketenkete ba a, ɛma ɛyɛ mmerɛw sɛ ɛbɛpaapae. Wubetumi ayɛ mpataayi asau ho mfonini wɔ w’adwenem. Sɛ ne ntini no dɔɔso dodo na ɛyɛ den dodo a, ɛhwere ne ho a ɛyɛ mmerɛw sɛ ɛbɛdannan ne ho na sɛ wɔtwe a, ɛpaapae ntɛmntɛm.
. Nnuru a ɛyɛ adwuma: Nkɔnsɔnkɔnsɔn titiriw no bubu, na ɛma cyclic oligomers (te sɛ D3, D4, ne nea ɛkeka ho) ne molecule nketewa afoforo ba.
Nea efi mu ba: Polymer nkɔnsɔnkɔnsɔn no tenten yɛ tiaa na molecule mu duru so tew. Eyi ma nneɛma no mu ahoɔden so tew tẽẽ. Sɛ nkɔnsɔnkɔnsɔn no yɛ tiaa dodo a, ade no ntumi nnyina adwennwen no ano yiye na ɛbɛyɛ mmerɛw nso. Saa adeyɛ yi betumi aba wɔ oxygen a ɛwɔ hɔ ne nea enni hɔ nyinaa mu, nanso ɛho hia titiriw wɔ ɔhyew a ɛkɔ soro kɛse mu.
3. Nneɛma a ɛyɛ hyew ne plasticizers a ɛyera: bere a wɔreyɛ silicone rɔba no, ebia bi a ɛba fam-molecular-eight siloxanes no bɛkɔ so atra hɔ, anaasɛ wobetumi de nneɛma bi aka ho na ama wɔatumi ayɛ adwuma no yiye. Wɔ bere tenten-bere a ɛyɛ hyew a ɛkɔ soro ase no, saa nneɛma a emu duru yɛ kɛse-Molecular saa nneɛma yi de nkakrankakra bɛhyew anaasɛ ɛbɛtu afi hɔ.
Nea efi mu ba: Ɛde besi baabi no, saa nneɛma yi di dwuma wɔ srade a ɛwɔ nipadua no mu ne nea ɛma ɛyɛ plastic mu. Wɔn adehwere no bɛma nsɛm no ayɛ den, ayɛ mmerɛw na ayɛ mmerɛw.
4.Thermal cycling ne adwennwene brɛ .
Adeyɛ: Sɛ awɔw ne ɔhyew a ɛyɛ hyew taa ba wɔ dwumadie tebea no mu a, silicone rɔba bɛtrɛw bere nyinaa na ayɛ apam.
Nea efi mu ba: Saa nhyɛso a ɛba bere ne bere mu yi betumi ama microcracks aba nneɛma no mu. Wɔ ɔhyew a ɛkɔ soro a ɛma nneɛma yɛ kɛse no ase no, saa nketenkete yi bɛma wɔn ntrɛwmu ne wɔn nkitahodi ayɛ ntɛmntɛm, na awiei koraa no ɛbɛma nneɛma no mu apaapae kɛse.