本文選題：尼龍66 + 熱降解�。� 參考：《東華大學(xué)》2017年碩士論文

【摘要】：尼龍66(PA66)熱穩(wěn)定性差,無(wú)氧條件下也易在熔點(diǎn)以上的溫度發(fā)生熱降解反應(yīng),并伴有交聯(lián)反應(yīng)。交聯(lián)反應(yīng)會(huì)進(jìn)一步生成凝膠,會(huì)影響PA66工業(yè)化生產(chǎn)中的管道運(yùn)輸以及后續(xù)的紡絲工作,給企業(yè)造成經(jīng)濟(jì)損失。因?yàn)槟z的產(chǎn)生是PA66無(wú)氧熱降解過程中的一個(gè)伴隨反應(yīng),所以要達(dá)到抑制凝膠產(chǎn)生的目的,必須對(duì)PA66無(wú)氧熱降解的反應(yīng)過程和機(jī)理進(jìn)行研究。國(guó)內(nèi)外對(duì)無(wú)氧熱降解機(jī)理有較為深入的研究,但對(duì)抑制凝膠產(chǎn)生的研究較少。本文首先對(duì)PA66在熱降解過程中結(jié)構(gòu)以及熱性能的變化進(jìn)行了測(cè)試和分析。然后研究了不同受阻胺對(duì)PA66熱處理過程中凝膠含量、熱性能和結(jié)構(gòu)變化的影響。最后通過原位聚合制備含有受阻胺的PA66以及PA66和PA6T共聚產(chǎn)物PA6AT,對(duì)制備的產(chǎn)物進(jìn)行了結(jié)構(gòu)的表征,測(cè)試了凝膠含量以及熱性能隨熱處理時(shí)間的變化。主要研究?jī)?nèi)容如下:(1)隨著熱處理時(shí)間的增加,凝膠含量先緩慢增長(zhǎng),到達(dá)一定時(shí)間后,凝膠含量迅速增加,最后增長(zhǎng)速度逐漸變慢。熱處理過程中PA66樣品中的酰胺鍵濃度降低,生成末端氨基和含有環(huán)戊酮基團(tuán)的物質(zhì),末端氨基也進(jìn)一步發(fā)生了反應(yīng)。PA66的熔融峰溫度和結(jié)晶峰溫度隨著熱處理時(shí)間的延長(zhǎng)逐漸向低溫方向移動(dòng),說明隨熱處理時(shí)間延長(zhǎng),PA66晶體穩(wěn)定性下降,結(jié)晶困難。(2)使用熔融共混的方法制備了PA66/受阻胺A(PA66/HAA)、PA66/受阻胺B(PA66/HAB)和PA66/受阻胺C(PA66/HAC)。在相同熱處理時(shí)間內(nèi),PA66/HAA和PA66/HAB的凝膠含量均低于PA66,其中PA66/HAA的凝膠含量最低,而PA66/HAC的凝膠含量比PA66高。熱處理后的PA66/HAA和PA66/HAB的熔融峰溫度和結(jié)晶峰溫度下降幅度均小于PA66。而熱處理6h的PA66/HAC的熔融峰溫度和結(jié)晶峰溫度下降幅度大于PA66。(3)制備了PA6T鹽,然后通過聚合的方式制備了PA66、PA66/HAA、PA66/HAB和PA6AT。確認(rèn)了PA6T鹽的結(jié)構(gòu)以及PA6AT是由PA66鹽和PA6T鹽共聚制備的。在相同熱處理時(shí)間內(nèi),聚合制備的PA66/HAA和PA66/HAB的凝膠含量仍低于PA66,且PA66/HAA效果最好。制備的PA6T質(zhì)量分?jǐn)?shù)為10%的PA6AT的凝膠含量比PA66高。未熱處理的PA66/HAA、PA66/HAB和PA6AT的熔融峰溫度分別比PA66低了0.1℃、1.1℃和2.9℃。熱處理6h后,PA66/HAA、PA66/HAB的熔融峰溫度和結(jié)晶峰溫度向低溫方向的偏移量比PA66小,其中PA66/HAA最小。熱處理6h后PA6AT的熔融峰溫度和結(jié)晶峰溫度向低溫方向偏移最大。
[Abstract]:The thermal stability of nylon 66 / PA66 is poor, and the thermal degradation reaction is easy to occur at the temperature above the melting point in the absence of oxygen, accompanied by crosslinking reaction. The crosslinking reaction will further produce gels, which will affect the pipeline transportation and subsequent spinning in the industrial production of PA66, and cause economic losses to the enterprises. Because the production of gel is an accompanying reaction in the process of anaerobic thermal degradation of PA66, it is necessary to study the reaction process and mechanism of anaerobic thermal degradation of PA66 in order to inhibit the formation of PA66. The mechanism of anaerobic thermal degradation has been studied deeply at home and abroad, but little research has been done on the inhibition of gel production. In this paper, the structure and thermal properties of PA66 during thermal degradation were tested and analyzed. The effects of different hindered amines on the gel content, thermal properties and structure of PA66 during heat treatment were studied. Finally, PA66 containing hindered amine and PA6ATs of PA66 and PA6T were prepared by in-situ polymerization. The structure of the prepared products was characterized and the changes of gel content and thermal properties with heat treatment time were tested. The main contents of the study are as follows: (1) with the increase of heat treatment time, the gel content increases slowly at first, after a certain time, the gel content increases rapidly, and finally the growth rate becomes slower. During heat treatment, the concentration of amide bonds in PA66 samples decreases to form terminal amino groups and substances containing cyclopentanone groups. The melting peak temperature and crystallization peak temperature of reaction .PA66 moved gradually to low temperature with the prolongation of heat treatment time, which indicated that the crystal stability decreased with the prolongation of heat treatment time. The PA66/ hindered amine APA66 / Ha-PA66 / PA66/ hindered amine CPA66 / HAB2 were prepared by melt-blending method. The gel content of PA66% HAA and PA66/HAB was lower than that of PA66 at the same heat treatment time, and the gel content of PA66/HAA was the lowest, while that of PA66/HAC was higher than that of PA66. The melting peak temperature and crystallization peak temperature of PA66/HAA and PA66/HAB decreased less than that of PA66 after heat treatment. However, the melting peak temperature and crystallization peak temperature of PA66/HAC after 6 h heat treatment decreased more than that of PA66. (3) PA6T salt was prepared, and then PA66 / PA66 / HAA PA66 / HAPA 66 / HAB and PA6ATs were prepared by polymerization. The structure of PA6T salt and the preparation of PA6AT by copolymerization of PA66 salt and PA6T salt were confirmed. The gel content of PA66/HAA and PA66/HAB prepared by polymerization is still lower than that of PA66 in the same heat treatment time, and PA66/HAA is the best. The gel content of PA6AT with 10% PA6T was higher than that of PA66. The melting peak temperatures of PA66 / HA / PA66 / HAB and PA6AT were 0.1 鈩，

本文編號(hào)：1883593