CAJ | 학술논문

为改善木塑复合材料密度大、韧性差的缺陷，采用注塑法制备竹粉/聚丙烯（polypropylene，PP）发泡复合材料；同时为加强木塑材料的生产和质量管理，采用氙灯加速老化方式，研究老化对发泡复合材料力学性能、材色、流变性能的影响，并采用环境扫描电镜（environmental scanning electronic microscopy, ESEM）和傅里叶红外光谱（Fourier transform infrared spectrum, FTIR）对材料进行分析。结果表明：历时1200 h氙灯加速老化后，材料的弯曲强度、弯曲模量和缺口冲击强度的保留率仅分别为79.4%、68.3%和75.6%；产生的色差ΔE*和白度变化值ΔL*分别为49.0和48.4。频率扫描结果显示，老化后，复合材料的模量和黏度下降。ESEM显示，老化后材料表面出现孔洞和裂缝，且部分竹粉暴露在材料表面。FTIR结果表明，老化过程中，复合材料发生了光氧化降解反应。该研究可为进一步探索竹塑发泡复合材料的老化规律，制定产品标准提供试验数据和理论参考。
위개선목소복합재료밀도대、인성차적결함，채용주소법제비죽분/취병희（polypropylene，PP）발포복합재료；동시위가강목소재료적생산화질량관리，채용선등가속노화방식，연구노화대발포복합재료역학성능、재색、류변성능적영향，병채용배경소묘전경（environmental scanning electronic microscopy, ESEM）화부리협홍외광보（Fourier transform infrared spectrum, FTIR）대재료진행분석。결과표명：력시1200 h선등가속노화후，재료적만곡강도、만곡모량화결구충격강도적보류솔부분별위79.4%、68.3%화75.6%；산생적색차ΔE*화백도변화치ΔL*분별위49.0화48.4。빈솔소묘결과현시，노화후，복합재료적모량화점도하강。ESEM현시，노화후재료표면출현공동화렬봉，차부분죽분폭로재재료표면。FTIR결과표명，노화과정중，복합재료발생료광양화강해반응。해연구가위진일보탐색죽소발포복합재료적노화규률，제정산품표준제공시험수거화이론삼고。
In order to reduce the density and improve the toughness of wood-plastic composite (WPC), the foamed WPC was made through adding chemical foaming agent in this study. To fully utilize bamboo resources in China and reduce white pollution, the foamed composite with 54% PP and 13% HMSPP containing 33%bamboo powder and 1%modified azodicarbonamide (AC) foaming agent blends by weight was made by injection molding. Furthermore, the aging performance of bamboo powder/polypropylene (PP) foamed composites was studied in order to investigate the weathering mechanism of WPC and to strengthen its production and quality management and thus expand its application fields. The composites were exposed to 1 200 h accelerated xenon-arc radiation with water spray, the mechanical characteristics including bending performance, notched impact strength, and color change of composites were studied. The rheological behavior of composites with regard to frequency sweep ranges from 0.01 to 70 Hz at 195℃was observed. The surface morphology of composites with non-weathered and weathered for 1 200 h were investigated by ESEM and their chemical structures were analyzed by FTIR. The results showed that the mechanical properties of composites decreased significantly for weathering 300 h and decreased continuously with an increase of exposure time. The retentions of residual bending strength, flexural modulus and notched impact strengths were only 79.4%, 68.3%and 75.6%respectively. The weathering also resulted in significant color fading of the composites, especially for the first 900 h. The color began to change slowly within the next 300 h. After weathering for 1 200 h, the color changeΔE*, lightness changeΔL*, redness changeΔa*and yellowness changeΔb*were 49.0, 48.4,-5.9 and-4.9 respectively. The frequency sweep results indicated that the storage modulus, loss modulus and complex viscosity of composite weathered for 1 200 h decreased and the intersection value of energy storage modulus and loss modulus become lower, and the corresponding frequency was higher. These results indicated that the molecular weight distribution become wider and the molecular weight became lower. The ESEM observation revealed that the surface of weathered composite was no longer smooth;and the cracks and holes appeared and some bamboo fibers exposed. The FTIR analysis showed the new peak of C=O stretching vibration at 1 717 cm-1 appeared and C=C absorption peak at 1 459 cm-1 strengthened and C=O stretching vibration peak at 1 059 cm-1 also strengthened. The FTIR result verified the photooxidation and photodegradation of composites for accelerated weathering.