成核劑對PET結(jié)晶行為及形態(tài)結(jié)構(gòu)影響的研究

1、成核劑對pet結(jié)晶行為及形態(tài)結(jié)構(gòu)影響的研究 湖北工業(yè)大學(xué) 碩士學(xué)位論文 成核劑對pet結(jié)晶行為及形態(tài)結(jié)構(gòu)影響的研究 姓名：胡小明 申請學(xué)位級別：碩士 專業(yè)：材料學(xué) 指導(dǎo)教師：嚴(yán)海彪 20100501 湖 北 工 業(yè) 大 學(xué) 碩 士 學(xué) 位 論 文 摘 要 本文系統(tǒng)地研究了四種成核劑：n-a 、液晶vectraa950 、滑石粉、ebs 對pet 的結(jié)晶行為、結(jié)晶形態(tài)、結(jié)晶結(jié)構(gòu)的影響。采用差式掃描量熱儀(dsc)研究了pet/ 成核劑復(fù)合體系的結(jié)晶行為，并用jeziorny 理論對pet 結(jié)晶過程進(jìn)行了動力學(xué)分 析；通過偏光顯微鏡（pom ）、小角激光散射（sals）、x 衍射（xrd ）對pe

2、t/ 成核劑復(fù)合體系的結(jié)晶形態(tài)和結(jié)晶結(jié)構(gòu)進(jìn)行了研究。 dsc 測試結(jié)果表明四種成核劑加入到pet 熔體中，均使得pet 的玻璃化溫度 和冷結(jié)晶溫度降低，而熱結(jié)晶溫度和熔融溫度升高；同時(shí)pet/成核劑復(fù)合體系的 表觀誘導(dǎo)期、半結(jié)晶時(shí)間、表觀總結(jié)晶時(shí)間都比純pet 的短；通過jeziorny 理論 對pet/成核劑復(fù)合體系進(jìn)行非等溫動力學(xué)研究，結(jié)果顯示隨著成核劑的加入， avrami 常數(shù)n 減小，結(jié)晶速率常數(shù)zc 增大?？梢姵珊藙┑募尤胗欣趐et 的成核， 縮短了pet 的結(jié)晶周期，加快了pet 的結(jié)晶速率。其中效果最好的是成核劑n-a 。 通過pom對pet/成核劑復(fù)合體系結(jié)晶形態(tài)進(jìn)行研究，

3、結(jié)果表明四種成核劑的 加入，均使得pet 的成核密度增大，晶體尺寸變小，晶體分布更加均勻；采用sals 法來定量分析四種成核劑的加入對pet 晶體尺寸和結(jié)晶誘導(dǎo)時(shí)間的影響，發(fā)現(xiàn)四種 成核劑都能細(xì)化pet 晶體尺寸，同時(shí)縮短了pet 的結(jié)晶誘導(dǎo)時(shí)間，加快了pet 的成 核，促進(jìn)了pet 的結(jié)晶，其中效果最為明顯的也是成核劑n-a 。通過xrd對成核劑 加入后的復(fù)合體系的結(jié)晶結(jié)構(gòu)進(jìn)行分析，發(fā)現(xiàn)晶胞并無變化，但是垂直于晶面 010、100的平均晶粒尺寸減小了，總結(jié)晶度變大了，這也表明成核劑的加入細(xì) 化了pet 的晶體尺寸，促進(jìn)了pet 的結(jié)晶。 綜合考慮四種成核劑對pet 結(jié)晶行為、結(jié)晶形態(tài)、結(jié)晶結(jié)

4、構(gòu)的影響，我們發(fā) 現(xiàn)成核效果最好的是成核劑n-a ，其次是滑石粉、液晶材料，最后是ebs 。 關(guān)鍵詞：pet ，成核劑，結(jié)晶行為，結(jié)晶形態(tài)，結(jié)晶結(jié)構(gòu) i 湖 北 工 業(yè) 大 學(xué) 碩 士 學(xué) 位 論 文 abstract in this paper, the effects of four kinds of nucleating agents such as: n-a,lcd vectraa950,talc,ebs on the crystallization behaviors, crystallization morphology and crystallization structure

5、were systematic studied. the crystallization behaviors of pet/nucleating agent blends by differetical scanning calorimetry(dsc), and the kinetics of pet crystallization were analysised by jeziorny theory; the crystallization morphology and crystallization structure of pet/nucleating agent composites

6、 were inverstigated by polarizing optical microscope(pom),small angle laser scattering(sals) and x ray diffraction(xrd),respectively. according to dsc, the glass trasition temperature and the temperature of cooling crystallization decreased by adding these four nucleating agents, while the heating c

7、rystallization temperature and melting temperature were increased; at the same time ,the apparent induction period ,the half time of crystallization,the apparent total time of crystallization of pet/nucleating agents blends were shorter than pure pet;non-isothermal crystallization kinetics of pet/nu

8、cleating agents blends were studied by jeziorny thory, the results showed that avrami constant n decreased and the crystallization z increased with nucleating agents adding.these were indicated that the c added of nucleating agents promoted the nucleating of pet,shorten the crystallization time of p

9、et, among which nucleating agent n-a was the best one. the results of the study on crystallization morphology of pet/nucleating agent composites by pom indicated that four nucleating agents all increased the density of nucleating , lessened the size of crystals, and the crystals were distributed mor

10、e evenly;the effects of adding four nucleating agents on the crystal size and the induction time of crystallization were quantitative anlysisted by sals, the results show that these four nucleating agents all can lessened the size of crystals ,shortened the induction time of crystallization of pet,a

11、ccelerated the nucleation and promoted the crystallization of pet. nucleating agent n-a was the best of these four. crystallization structure of pet/nucleating agents composites were analysised by xrd, the results showed that crystal cells were not changed, but the average size of crystals which per

12、pendiculared to the crystal surface 010,100were lessened, while the total degree of crystalinity was largered,which also indicated that it could lessened the size of crystal and promote the crystallization of pet by adding nucleating agents. the effects of four nucleating agents on pet crystallization behaviors, crystallization morphology and crystallization structure were amprehensive considerated, finally we found nucleating agents n-a was the best nucleating agent fo