Effect of treatment on cellulose crystallinity and properties of parawood strands

Name: Wanchai Phetkaew

Abstract: The purpose of this research was to study the effect of heat treatment on color change, cellulose crystallinity, cellulose structure, and tensile strength of Parawood strands by measuring the physical properties, ie., the quantity of heat used to decompose the crystallinity of cellulose as well as the mechanical properties, i.e., the ultimate tensile stress parallel to grain and work to maximum load (toughness) according to the condition of the three factors of the factorial experiment (moisture content in wood, temperature, and time for heat treatment). The result indicated that the color change to bright (L) of oven-dried Parawood stands, 12% MC Parawood strands and boiled Parawood strands had changed value of 71.98-49.76%, 79.08-55.61% and 77.55-65.16%, respectively. Red shade (a) had changed to 8.69-5.83%, 7.62-3.05% and 6.58-2.60%, respectively. Yellow shade (b) had changed to 18.67-16.32%, 18.76-17.39% and 18.36-14.50%, respectively. The result indicated that the physical properties for the quantity of heat used to decompose crystallites of cellulose and the percentage of cellulose crystallinity of boiled Parawood strands under heat treatment at 190C in 30 min had the maximum values of 215.23 J/g and 73.88%, respectively. The mechanical properties for ultimate tensile stress parallel to grain and work to maximum load of the boiled Parawood strands under heat treatment at 190C in 30 min revealed the maximum value of 56.98 MPa and 0.75 J/mm3, respectively. The molecular structure of cellulose in Parawood strand treated with oven drying, 12% of moisture content and water boiling is still intact; however, there are changes in their crystallinity. The result of the experiment could be concluded that the physical and mechanical properties had the maximum values coincided at the same temperature and time of heat treatment. For the boiled Parawood stands under the heat treatment at 190C in 30 min, the highest strength of tensile stress parallel to grain and the highest toughness increased by 30% and 79%, respectively.

WALAILAK UNIVERSITY. CENTER FOR LIBRARY RESOURCES AND EDUCATIONAL MEDIA

Address: NAKON SI THAMMARAT

Email: clm@wu.ac.th

Name: Asst. prof. Dr. Sureurg Khongtong

Role: Chairman

Created: 2008-10-01

Modified: 2024-08-20

Issued: 2008-10-01

วิทยานิพนธ์/Thesis

application/pdf

eng

DegreeName: Doctor of Philosophy (Materials Science and Engineering)

Level: Doctoral Degree

Descipline: Materials Science and Engineering

Grantor: Walailak University

©copyrights Walailak University

ลำดับที่.	ชื่อแฟ้มข้อมูล	ขนาดแฟ้มข้อมูล	จำนวนเข้าถึง	วัน-เวลาเข้าถึงล่าสุด
1	Title pages.pdf	26.73 KB	4	2018-05-14 08:16:02
2	Approval page.pdf	65.62 KB	4	2018-05-14 08:16:04
3	Abstract.pdf	99.31 KB	5	2018-05-14 08:16:05
4	Acknowledgement.pdf	59.52 KB	4	2018-05-14 08:16:06
5	Content.pdf	797.86 KB	4	2018-05-14 08:16:07
6	Chapter1.pdf	399.47 KB	4	2018-05-14 08:16:08
7	Chapter2.pdf	1.11 MB	11	2018-05-14 08:16:09
8	Chapter3.pdf	1.79 MB	5	2018-05-14 08:16:11
9	Chapter4.pdf	748.5 KB	4	2018-05-14 08:16:12
10	Chapter5.pdf	143.82 KB	4	2018-05-14 08:16:14
11	Appendix.pdf	2.24 MB	4	2018-05-14 08:16:15
12	CV.pdf	39.89 KB	4	2018-05-14 08:16:16

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