Sɛ wonya ɔhyew a ɛko tia ɔhyew a ɛboro digrii 300 wɔ silicone foam boards mu a, ɛde nsɛnnennen kɛse ba, efisɛ standard silicone nneɛma taa yɛ adwuma wɔ A-60℃kosi 200℃mu wɔ bere tenten-bere a wɔde di dwuma no mu, a bere tiaa mu ɔhyew a ɛsen biara a ebetumi adu 250℃. Sɛ ɔhyew boro saa aboboano yi so a, polymer akyi dompe no fi ase sɛe, na ɛde nneɛma a ɛyɛ mmerɛw ba, ɛyɛ den sɛ ɛbɛyera, na awiei koraa no, ɛbɛbɔ.
Sɛnea ɛbɛyɛ a wobenya ɔhyew a ɛko tia bɛboro 300℃, ɛho hia sɛ wɔyɛ nhyehyɛe a edi mũ ne optimization fi mfitiase nneɛma, reinforcement nhyehyɛe, ɔhyew-resistant additives, foaming process ne structure design.
Mfiridwuma ho akwan titiriw ne nea ɛsɛ sɛ wosusuw ho sɛ wobedu botae yi ho ne nea edidi so yi:
I. Nneɛma titiriw a wɔpaw ne nea ɛyɛ papa .
Eyi ne anammɔn titiriw a ɛsen biara.
Fa phenyl silicone rɔba a ɛkorɔn di dwuma:
Nnyinasosɛm: Silicone rɔba a ɛyɛ mmerɛw (methyl vinyl silicone rɔba) no ntumi nnyina ɔhyew ano. Phenyl akuw (titiriw diphenylsiloxane nkɔnsɔnkɔnsɔn afã horow a ɛdɔɔso) a wɔde ba siloxane nkɔnsɔnkɔnsɔn titiriw no mu no betumi ama ɔhyew a ɛko tia nneɛma no atu mpɔn kɛse.
Dwumadi: Benzene ring no nhyehyɛe a ɛyɛ kɛse ne ne conjugation effect no betumi abɔ ɔhyew no ho ban yiye na ama ayɛ den-Sensitive Si-O nkitahodi ahorow, na ɛnam so asiw thermal cyclization degradation ne oxidative cleavage a ɛwɔ polymer chain no mu no ano. High-phenyl silicone rɔba betumi agyina tenten-bere mu hyew a ɛkɔ soro kodu 250-300℃ne bere tiaa mu ɔhyew a ɛboro 350℃.
Fa fumed silica di dwuma sɛ ade a ɛhyɛ mu den:
Necessity: Silica gel a wɔmfa nhyɛ mu den no wɔ ahoɔden a ɛba fam koraa. Fumed silica (nanoscale silica) nkutoo ne ade a ɛhyɛ den a ebetumi ama ahoɔden a silica gel hwehwɛ no.
Ahwehwɛdeɛ: Ɛsɛ sɛ wɔde soro-purity fumed silica a ɛwɔ ayaresa soronko, particle size ketewa ne kɛseɛ pɔtee a ɛwɔ soro no di dwuma. Ebetumi ayɛ nano-network nhyehyɛe a ɛyɛ den wɔ silica matrix no mu na akura mfiridwuma su ahorow bi mu mpo wɔ ɔhyew a ɛkorɔn mu.
ii. Ɔhyew a ɛko tia additive nhyehyɛe .
Ɛnnyɛ nea ɛdɔɔso sɛ wode wo ho bɛto nneɛma atitiriw nkutoo so, na ɛsɛ sɛ wɔde ɔhyew soronko-aduru a ɛko tia nneɛma ka ho "bɔ ho ban na ɛka ho".
Ɔhyew a ɛma ɛyɛ hyew:
1)Iron Oxide (Fe2o₃): Eyi ne ɔhyew a ɛyɛ nwonwa na etu mpɔn sen biara-ɛko tia ade a wɔde ka ho. Reddish-brown -Fe2o3 na wɔtaa de di dwuma. Ɛkyere free radicals a ɛtow hyɛ siloxane akyi dompe no so wɔ ɔhyew a ɛkɔ soro mu na ɛma siloxane a ɛyɛ den kɛse-carbon structures no ba, na ɛnam so siw akyi dompe a ɛsɛe no ano. Mpɛn pii no, dodow a wɔde ma no fi 0.5 kosi 3.
2)Cerium oxide (CEO2) yɛ asase a ɛho yɛ na a ɛyɛ adwuma yiye-gyina ɔhyew-ɛko tia stabilizer, titiriw bere a wɔaka abom ne Fe2O2. Ɛsiw silanol akuw no mu nsu a ɛyɛ nwini ne nea ɛyɛ hyew no ano yiye.
3)Asase oxide afoforo a ɛntaa nsi, te sɛ lanthanum oxide (LA2O4) nso kyerɛ sɛ ɔhyew no gyina yiye.
Paw vulcanization nhyehyɛe a ɛfata:
1)Peroxide vulcanization: Wɔ nneɛma a wɔde yɛ ahurututu mu no, peroxides (te sɛ BIS(2,5-TERTIARY)peroxide) yɛ nneɛma a wɔtaa de di dwuma wɔ vulcanizing mu. Ɛho hia sɛ wɔpaw peroxides a ɛwɔ nneɛma a ɛporɔw a ɛyɛ den ne nneɛma a ɛnyɛ nea ɛyɛ mmerɛw, bere a wɔhwɛ hu sɛ vulcanization a edi mũ wom na amma nneɛma a aka no ansɛe wɔ ɔhyew a ɛkɔ soro ase no.
2)platinum sulfide (Addition sulfide) ne nea wɔpɛ bere a foam-forming processes ma ho kwan no. Ne cross-a ɛbata SI-C nhyehyɛe no da ɔhyew ano aduru a ɛkorɔn adi bere a wɔde toto C-C nkitahodi ahorow a ɛwɔ peroxide-gyina nhyehyɛe ahorow mu no ho, a enni decomposition residues. Nanso, platinum-gyinaso nhyehyɛe ahorow hwehwɛ sɛ wɔyɛ nhyehyɛe a emu yɛ den na wɔhwɛ nneɛma a atwa yɛn ho ahyia so na ɛyɛ mmerɛw sɛ wobenya awuduru.
iii. Nsɛnnennen a ɛwɔ foaming nhyehyɛe ahorow mu .
Bere a ɛredi ɔhyew a ɛkɔ soro a ɛko tia no akyi no, ɛho hia nso sɛ wonya ahurututu a ɛyɛ pɛ na ɛyɛ den.
Nnuru a ɛma ahurututu mu nsu yɛ hyew: Ɛsɛ sɛ ɔhyew a ɛporɔw no ne vulcanization hyew no hyia, na ɛsɛ sɛ ade a ɛporɔw no yɛ mframa a ɛnyɛ adwuma (te sɛ nitrogen). Ɛnsɛ sɛ decomposition nkae no ma silica gel matrix no sɛe no yɛ kɛse.
Nipadua mu ahurututu: Mfiridwuma te sɛ supercritical fluid foaming betumi akwati ɔhaw a ɛne nnuru a ɛma ahurututu mu nneɛma nkae no, nanso nnwinnade a wɔde hyɛ mu no yɛ kɛse na ɔkwan a wɔfa so yɛ no yɛ den.
Asɛm titiriw: ɛmfa ho sɛnea wɔde ahurututu mu aduru di dwuma no, ɛho hia sɛ wɔhwɛ hu sɛ nkwammoaa no nhyehyɛe no gyina na nkwammoaa no fasu no yɛ den. Nkwammoaa a ɛbue anaa nkwammoaa fasuo a ɛyɛ mmerɛw no bɛhwe ase anaasɛ ɛbɛbubu ntɛmntɛm wɔ ɔhyew a ɛkɔ soro mu, na ɛde ɔhyew a wɔde siw ano no adwumayɛ so atew kɛse aba.
iv. Nhyehyɛe ne post-processing nhyehyɛe .
Nkɔanim density/reduce bubbles: Wɔ premise a edi mu duru ne softness ahwehwɛde, ɔkwan a ɛfata so ma density a foam board (kyerɛ sɛ, tew foaming ratio) betumi anya thicker na ɔhyew-resistant tokuru ɔfasu, na ɛnam so ma nyinaa ɔhyew resistance ne mfiri ahoɔden.
Nneɛma a wɔabom ayɛ: Susuw ho sɛ wobɛbɔ "sandwich" nhyehyɛe, sɛ nhwɛso no, afã abien a wɔde soro-temperature resistant non{1}}porous silicone film anaa glass fiber ntama ayɛ, ne foamed layer wɔ mfinimfini. Eyi betumi abɔ fragile porous structure no ho ban afi tẽẽ a ɛkɔ ɔhyew a ɛkɔ soro tebea mu.
Post-High temperature Vulcanization: Ɛsɛ sɛ wɔde foam board a wɔayɛ no yɛ post-High temperature vulcanized (sɛ nhwɛso no, wɔde nnɔnhwerew pii a ɛyɛ 200-250℃) na ama wɔayi molecule a ɛba fam a ɛyɛ hyew no afi hɔ koraa na ɛma crosslinking network no gyina, a ɛho hia kɛse ma ɔhyew a ɛkɔ soro a wɔde di dwuma bere tenten no.