1. Reporter : Jia-Lin Lu Advisor: Cheng-Ho Chen Date :104/12/22

2. Introduction
Bamboo has been widely used in furniture manufacture, construction material and living tools for thousands of years, due to its fast growth, high strength and surface hardness as well as easy machinability .
During the last decade, many research activities have been dedicated to natural fiber reinforced thermoplastic composites. Especially polypropylene (PP), polyethylene (PE), polyvinyl chloride (PVC) and poly(lactic acid) (PLA) matrices composites are gaining increasing interest .

3. Introduction
Bamboo fiber or bamboo particle reinforced polymer composites drawing attention have also been fabricated and investigated.
However, being hydrophilic because of the hydroxyl, bamboo fibers do not adhere well to hydrophobic polymer matrices and absorb water from surrounding media or moisture. The compatibility between bamboo fiber and polymer matrix is poor leading to a weak mechanical property.
Therefore, improvement of interfacial compatibility between bamboo fiber and polymer resin matrix is the key to fabricate PVC/BP composites with excellent property.

4. Introduction
Hydrothermal pretreatment using hot water is an environmental friendly approach for processing of lignocellulosic biomass due to its advantages of chemical free, low operational costs and potential on hemicelluloses dissolution.
Hydrothermal pretreatment of biomass not only degraded most of the hemicellulose and part of the cellulose, but also eliminated the sugar, starch, and protein on the surface of BP, which resulted in a lower molecule polarity of BP and a better interfacial compatibility with polymer matrix.

5. Materials Moso bamboo (particle size is 200-400 mm)
Granulated PVC (particle size is 300 mm)

6. Method
Step 1. About 200 g of moso bamboo particles were immersed in water with a ratio of 1:5 (wt/v).
Step 2. Then, they were hydrothermal treated for different temperatures (120, 140, 160, 180, 200, 220, 240, 260 and 280C) for 30 min in a closed high temperature high pressure autoclave.
The pressure was kept at saturated vapor pressure of each temperature.
Step 3. After that, BPs was cooled to ambient temperature and washed with distilled water for several times till the color no longer change.
Then, they were dried in a blast drying oven.
Step 4. Closed mould hot compressing technique was used to fabricate PVC/BP composites in this study.
Moso bamboo particles obtained after surface modification were mixed with PVC at a weight proportion of 7:3.
Step 5. The mould was preheated at 170°C for 3 min, and pressed at 180°C by a pressure of 10 MPa for 5 min.

7. Results and discussion – Composition analysis
Table 1
Composition of the hydrothermal treated BP.
About 1.00 g of sample was ground into fine powder, and the contents of neutral detergent fiber, acid detergent fiber, acid detergent lignin, and acidinsoluble ash, respectively, were extracted by a series of solutions and solvents.

8. Results and discussion - Micromorphology of BP
Fig. 1. Surface morphology of BP: a) untreated, b) hydrothermal pretreated at 160°C,
c) hydrothermal pretreated at 200°C, and d) hydrothermal pretreated at 260°C

9. Results and discussion - Mechanical properties
Table 2
Mechanical properties of PVC/BP composites.

10. Results and discussion - Micromorphology of PVC/BP composites
Fig. 4. Micro-morphology of PVC/BP composites: a) Raw BP,
b) 160C hydrothermal pretreated c), 200C hydrothermal pretreated, and d) 260C hydrothermal pretreated.

11. Results and discussion – Thermal behavior of PVC/BP composites
Table 3
Thermal behavior parameters of PVC/BP composites.

12. Conclusions
Hydrothermal treatment was employed to modify moso bamboo particles surface and then reinforced PVC composites.
Surface texture of moso bamboo particles were changed; hemicellulose, lignin and pectin were removed, but excess temperature would give rise to the degradation of cellulose.
The mechanical properties of BP reinforced PVC composites increased with the increase of treating temperature, and then decreased.
Thermal behavior analysis revealed that higher temperature treated PVC/BP composites had better thermal stability.