尼(ni)龍(long)材(cai)料(liao)加(jia)入(ru)玻(bo)璃(li)纖(xian)維(wei)後(hou)阻(zu)燃(ran)性(xing)能(neng)下(xia)降(jiang)的(de)現(xian)象(xiang),主(zhu)要(yao)源(yuan)於(yu)複(fu)合(he)材(cai)料(liao)體(ti)係(xi)內(nei)多(duo)組(zu)分(fen)間(jian)的(de)相(xiang)互(hu)作(zuo)用(yong)。玻(bo)璃(li)纖(xian)維(wei)作(zuo)為(wei)增(zeng)強(qiang)相(xiang),雖(sui)然(ran)提(ti)升(sheng)了(le)材(cai)料(liao)的(de)機(ji)械(xie)強(qiang)度(du),但(dan)其(qi)高(gao)導(dao)熱(re)性(xing)改(gai)變(bian)了(le)熱(re)量(liang)傳(chuan)遞(di)路(lu)徑(jing)。在(zai)燃(ran)燒(shao)過(guo)程(cheng)中(zhong),玻(bo)璃(li)纖(xian)維(wei)形(xing)成(cheng)的(de)網(wang)絡(luo)結(jie)構(gou)成(cheng)為(wei)熱(re)傳(chuan)導(dao)的(de)快(kuai)速(su)通(tong)道(dao),加(jia)速(su)了(le)熱(re)量(liang)的(de)擴(kuo)散(san),使(shi)材(cai)料(liao)整(zheng)體(ti)溫(wen)度(du)迅(xun)速(su)上(shang)升(sheng)。這(zhe)種(zhong)熱(re)傳(chuan)導(dao)效(xiao)應(ying)抵(di)消(xiao)了(le)阻(zu)燃(ran)劑(ji)通(tong)過(guo)吸(xi)熱(re)分(fen)解(jie)實(shi)現(xian)的(de)降(jiang)溫(wen)作(zuo)用(yong),導(dao)致(zhi)阻(zu)燃(ran)效(xiao)率(lv)降(jiang)低(di)。例(li)如(ru),純(chun)尼(ni)龍(long)在(zai)燃(ran)燒(shao)時(shi)表(biao)麵(mian)炭(tan)層(ceng)可(ke)隔(ge)絕(jue)部(bu)分(fen)熱(re)量(liang),而(er)玻(bo)纖(xian)增(zeng)強(qiang)材(cai)料(liao)中(zhong)熱(re)量(liang)通(tong)過(guo)纖(xian)維(wei)骨(gu)架(jia)快(kuai)速(su)傳(chuan)遞(di)至(zhi)內(nei)部(bu),使(shi)未(wei)燃(ran)燒(shao)區(qu)域(yu)提(ti)前(qian)達(da)到(dao)熱(re)分(fen)解(jie)溫(wen)度(du)。
zuranjiyuboxiandejiemianxiangrongxingwentijiajulezurannandu。bolixianweibiaomiantongchangjingguoguiwanoulianjichuliyizengqiangyunilongdejieheli,danzhexiechulicengkenengzuaizuranjifenzizaijitizhongdejunyunfensan。linxi、氮(dan)係(xi)等(deng)常(chang)用(yong)阻(zu)燃(ran)劑(ji)容(rong)易(yi)在(zai)玻(bo)纖(xian)表(biao)麵(mian)富(fu)集(ji),形(xing)成(cheng)局(ju)部(bu)濃(nong)度(du)過(guo)高(gao)區(qu)域(yu),而(er)其(qi)他(ta)區(qu)域(yu)則(ze)出(chu)現(xian)阻(zu)燃(ran)劑(ji)短(duan)缺(que)。這(zhe)種(zhong)分(fen)布(bu)不(bu)均(jun)導(dao)致(zhi)燃(ran)燒(shao)時(shi)無(wu)法(fa)形(xing)成(cheng)連(lian)續(xu)致(zhi)密(mi)的(de)保(bao)護(hu)炭(tan)層(ceng),氧(yang)氣(qi)和(he)可(ke)燃(ran)氣(qi)體(ti)仍(reng)能(neng)通(tong)過(guo)薄(bo)弱(ruo)區(qu)域(yu)持(chi)續(xu)參(can)與(yu)燃(ran)燒(shao)反(fan)應(ying)。實(shi)驗(yan)表(biao)明(ming),玻(bo)纖(xian)含(han)量(liang)超(chao)過(guo)20%時,阻燃劑的遷移聚集現象尤為顯著。
加工過程中的熱機械作用對阻燃體係產生雙重影響。玻纖增強尼龍需要更高的加工溫度(通常達280-300℃)以實現充分熔融,而多數阻燃劑在此溫度下會發生提前分解。例如,氫氧化鎂在260℃開(kai)始(shi)脫(tuo)水(shui)失(shi)活(huo),溴(xiu)係(xi)阻(zu)燃(ran)劑(ji)在(zai)高(gao)溫(wen)下(xia)可(ke)能(neng)釋(shi)放(fang)腐(fu)蝕(shi)性(xing)氣(qi)體(ti)。同(tong)時(shi),螺(luo)杆(gan)擠(ji)出(chu)時(shi)的(de)高(gao)剪(jian)切(qie)力(li)會(hui)使(shi)玻(bo)纖(xian)與(yu)阻(zu)燃(ran)劑(ji)顆(ke)粒(li)發(fa)生(sheng)摩(mo)擦(ca),導(dao)致(zhi)阻(zu)燃(ran)劑(ji)晶(jing)體(ti)結(jie)構(gou)破(po)壞(huai),降(jiang)低(di)其(qi)熱(re)穩(wen)定(ding)性(xing)。這(zhe)種(zhong)加(jia)工(gong)損(sun)耗(hao)使(shi)得(de)實(shi)際(ji)起(qi)作(zuo)用(yong)的(de)阻(zu)燃(ran)劑(ji)比(bi)例(li)遠(yuan)低(di)於(yu)理(li)論(lun)添(tian)加(jia)量(liang)。
cailiaoranshaoxingweidewulihuaxuebianhuayeshiguanjianyinsu。boxiandejiarushinilongrongtizhanduzengda,zuaileranshaoshirongdituoluodaizoureliangdeziwobaohujizhi。canliudeboxiangujiazairanshaohouxingchengduokongjiegou,fanerzengjialeyangqijiechumianji。gengfuzadeshi,boxianzhongdejinshulizi(如鈣、鋁)可ke能neng催cui化hua某mou些xie阻zu燃ran劑ji的de分fen解jie反fan應ying,改gai變bian其qi作zuo用yong機ji理li。例li如ru,三san氧yang化hua二er銻ti與yu鹵lu係xi阻zu燃ran劑ji的de協xie同tong效xiao應ying在zai玻bo纖xian存cun在zai時shi會hui被bei削xue弱ruo,因yin為wei金jin屬shu離li子zi優you先xian與yu鹵lu素su發fa生sheng反fan應ying生sheng成cheng揮hui發fa性xing物wu質zhi。這zhe些xie因yin素su共gong同tong作zuo用yong,使shi得de玻bo纖xian增zeng強qiang尼ni龍long的de阻zu燃ran設she計ji需xu要yao重zhong新xin平ping衡heng增zeng強qiang效xiao果guo與yu防fang火huo安an全quan的de矛mao盾dun。