東華大學圖書館 |

語系: 繁體中文

說明(常見問題)

回圖書館首頁

手機版館藏查詢

登入

回首頁

切換: 標籤 | MARC模式 | ISBD

Molecular modeling of amorphous and ...

Chen, Wei.

FindBook

Google Book

Amazon

博客來

Molecular modeling of amorphous and crosslinked cellulose.

紀錄類型:	書目-電子資源 : Monograph/item
正題名/作者:	Molecular modeling of amorphous and crosslinked cellulose./
作者:	Chen, Wei.
面頁冊數:	193 p.
附註:	Source: Dissertation Abstracts International, Volume: 62-10, Section: B, page: 4765.
Contained By:	Dissertation Abstracts International62-10B.
標題:	Textile Technology. -
電子資源:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3031112
ISBN:	0493433481

Molecular modeling of amorphous and crosslinked cellulose.
Chen, Wei.

Molecular modeling of amorphous and crosslinked cellulose. - 193 p.

Source: Dissertation Abstracts International, Volume: 62-10, Section: B, page: 4765.

Thesis (Ph.D.)--Clemson University, 2001.

Structure-property relationships in cellulose crosslinked with both conventional and elastomeric crosslinking agents were successfully calculated using molecular modeling. The observed yielding for these amorphous cellulose models, which occurred at approximately 8% strain according to the calculated stress-strain relationship, is due to the disruption of hydrogen bonds, the secondary crosslinks, between cellulose chain segments. Crosslinks hold cellulose chain segments together and block chain slippage to give cellulose fibers a higher initial modulus and better elastic response. However, these crosslinks restrict chain movement so that stress is concentrated in regions of the structure and cavities are formed and developed in these regions of the models, which correlate to final fiber failure.

ISBN: 0493433481Subjects--Topical Terms:

1020710
Textile Technology.

Molecular modeling of amorphous and crosslinked cellulose.
LDR:03412nmm 2200313 4500 001 1864832
005 20041216133439.5
008 130614s2001 eng d
020 $a 0493433481
035 $a (UnM)AAI3031112
035 $a AAI3031112
040 $a UnM $c UnM
100 1 $a Chen, Wei. $3 1064731
245 1 0 $a Molecular modeling of amorphous and crosslinked cellulose.
300 $a 193 p.
500 $a Source: Dissertation Abstracts International, Volume: 62-10, Section: B, page: 4765.
500 $a Adviser: Gary C. Lickfield.
502 $a Thesis (Ph.D.)--Clemson University, 2001.
520 $a Structure-property relationships in cellulose crosslinked with both conventional and elastomeric crosslinking agents were successfully calculated using molecular modeling. The observed yielding for these amorphous cellulose models, which occurred at approximately 8% strain according to the calculated stress-strain relationship, is due to the disruption of hydrogen bonds, the secondary crosslinks, between cellulose chain segments. Crosslinks hold cellulose chain segments together and block chain slippage to give cellulose fibers a higher initial modulus and better elastic response. However, these crosslinks restrict chain movement so that stress is concentrated in regions of the structure and cavities are formed and developed in these regions of the models, which correlate to final fiber failure.
520 $a The flexibility and response to applied external force for some potential crosslink structures were examined by molecular modeling. These molecules, which have small energy differences between conformational states, are highly coiled and have small mean end-to-end distances (accounting for 40% to 50% of the length of their fully extended chains). The presence of oxygen atoms in the backbone along with asymmetric non-polar side groups, such as methyl groups, can greatly reduce the energy difference and the energy barrier between conformational states and can thus make chains highly coiled and easy to be extended. Decane crosslinks introduced more freedom to cellulose chain segments but didn't improve the deformation recovery in cellulose models. Conformational transitions were observed in decane crosslinks during deformation. Cellulose models crosslinked with poly(propylene oxide) pentamers or with the N-methyl substituted peptide pentamers show good deformation recovery without affecting the breaking strain. Both crosslinks didn't significantly change the initial modulus and the yielding behavior of cellulose. No conformation transitions were observed in these crosslinks when crosslinked cellulose models were strained to 15% strain. These highly coiled, spring-like molecules are candidates for elastomeric crosslinking agents for cellulose materials.
520 $a Improvement in deformation recovery of cellulose models by elastomeric crosslinks is achieved by breaking newly formed hydrogen bonds and restoring the original hydrogen bonds. Elastomeric crosslinks can improve the deformation recovery of cellulose models without affecting the mechanical strength of cellulose.
590 $a School code: 0050.
650 4 $a Textile Technology. $3 1020710
650 4 $a Engineering, Materials Science. $3 1017759
650 4 $a Chemistry, Polymer. $3 1018428
690 $a 0994
690 $a 0794
690 $a 0495
710 2 0 $a Clemson University. $3 997173
773 0 $t Dissertation Abstracts International $g 62-10B.
790 1 0 $a Lickfield, Gary C., $e advisor
790 $a 0050
791 $a Ph.D.
792 $a 2001
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3031112