农业工程学报
農業工程學報
농업공정학보
2014年
10期
285-292
,共8页
周吓星%黄舒晟%苏国基%余雁%陈礼辉
週嚇星%黃舒晟%囌國基%餘雁%陳禮輝
주하성%황서성%소국기%여안%진례휘
复合材料%聚丙烯%傅里叶红外光谱%竹粉%冻融循环%老化
複閤材料%聚丙烯%傅裏葉紅外光譜%竹粉%凍融循環%老化
복합재료%취병희%부리협홍외광보%죽분%동융순배%노화
composite materials%polypropylenes (PP)%fourier transform infrared spectroscopy%bamboo flour%freeze-thaw cycles%weathering
竹粉/聚丙烯（polypropylene，PP）发泡复合材料具有密度低、比强度高等优点，为了探讨期老化规律，该文研究冻融循环对不同竹粉含量（0，20%，33%和42%）的发泡复合材料的材色、物理力学性能、热学性能的影响，并结合环境扫描电镜（environmental scanning electronic microscopy，ESEM）和傅里叶红外光谱（fourier transform infrared spectrum，FTIR）对复合材料的表面形貌及化学结构进行分析。结果表明：随着竹粉含量增加，冻融循环老化对复合材料的材色和物理力学性能影响越明显，且随着冻融循环次数的增加，复合材料产生的色差越大，力学性能降低越多。9次冻融循环后，0、20%、33%和42%竹粉/PP发泡复合材料产生的色差ΔE*分别为0.9、2.4、7.0和9.9，弯曲模量、弯曲强度、拉伸强度和缺口冲击强度的保留率分别为95.2%～99.1%、97.3%～98.9%、94.9%～97.5%和92.0%～95.6%。热重分析（thermogravimetric analysis，TG）结果表明，9次冻融循环老化后，0和33%竹粉/PP发泡复合材料的初始热分解温度分别下降了19和8℃。ESEM显示，老化后复合材料表面出现少量的裂纹以及褶皱，且少量的表层高分子层脱落。FITR 测试结果发现，冻融循环过程中复合材料的木材指数减少，表明材料表面的竹粉颗粒损失，且基体 PP 的基团峰强度减弱。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。
竹粉/聚丙烯（polypropylene，PP）髮泡複閤材料具有密度低、比彊度高等優點，為瞭探討期老化規律，該文研究凍融循環對不同竹粉含量（0，20%，33%和42%）的髮泡複閤材料的材色、物理力學性能、熱學性能的影響，併結閤環境掃描電鏡（environmental scanning electronic microscopy，ESEM）和傅裏葉紅外光譜（fourier transform infrared spectrum，FTIR）對複閤材料的錶麵形貌及化學結構進行分析。結果錶明：隨著竹粉含量增加，凍融循環老化對複閤材料的材色和物理力學性能影響越明顯，且隨著凍融循環次數的增加，複閤材料產生的色差越大，力學性能降低越多。9次凍融循環後，0、20%、33%和42%竹粉/PP髮泡複閤材料產生的色差ΔE*分彆為0.9、2.4、7.0和9.9，彎麯模量、彎麯彊度、拉伸彊度和缺口遲擊彊度的保留率分彆為95.2%～99.1%、97.3%～98.9%、94.9%～97.5%和92.0%～95.6%。熱重分析（thermogravimetric analysis，TG）結果錶明，9次凍融循環老化後，0和33%竹粉/PP髮泡複閤材料的初始熱分解溫度分彆下降瞭19和8℃。ESEM顯示，老化後複閤材料錶麵齣現少量的裂紋以及褶皺，且少量的錶層高分子層脫落。FITR 測試結果髮現，凍融循環過程中複閤材料的木材指數減少，錶明材料錶麵的竹粉顆粒損失，且基體 PP 的基糰峰彊度減弱。該研究可為進一步探索竹塑髮泡複閤材料的老化規律，製定產品標準提供試驗數據和理論參攷。
죽분/취병희（polypropylene，PP）발포복합재료구유밀도저、비강도고등우점，위료탐토기노화규률，해문연구동융순배대불동죽분함량（0，20%，33%화42%）적발포복합재료적재색、물리역학성능、열학성능적영향，병결합배경소묘전경（environmental scanning electronic microscopy，ESEM）화부리협홍외광보（fourier transform infrared spectrum，FTIR）대복합재료적표면형모급화학결구진행분석。결과표명：수착죽분함량증가，동융순배노화대복합재료적재색화물리역학성능영향월명현，차수착동융순배차수적증가，복합재료산생적색차월대，역학성능강저월다。9차동융순배후，0、20%、33%화42%죽분/PP발포복합재료산생적색차ΔE*분별위0.9、2.4、7.0화9.9，만곡모량、만곡강도、랍신강도화결구충격강도적보류솔분별위95.2%～99.1%、97.3%～98.9%、94.9%～97.5%화92.0%～95.6%。열중분석（thermogravimetric analysis，TG）결과표명，9차동융순배노화후，0화33%죽분/PP발포복합재료적초시열분해온도분별하강료19화8℃。ESEM현시，노화후복합재료표면출현소량적렬문이급습추，차소량적표층고분자층탈락。FITR 측시결과발현，동융순배과정중복합재료적목재지수감소，표명재료표면적죽분과립손실，차기체 PP 적기단봉강도감약。해연구가위진일보탐색죽소발포복합재료적노화규률，제정산품표준제공시험수거화이론삼고。
The wood-plastic foamed composites have lower density and higher specific strengths than wood-plastic composites (WPC) and thus have wide applications in fields such as building, decoration, packing, and the automobile industry. Previous studies showed that the weathering causes color fading, strength weakening, chemical changes of WPC, thereby restricting the specific outdoor applications of WPC. In order to explore their weathering mechanism and broaden their outdoor applications, it is of great importance to evaluate the durability of BF/PP foamed composites. The objective of this research was to study the impact of weathering of freeze-thaw cycle on the physical and thermal properties of bamboo flour-polypropylene foamed composite. The foamed composites of bamboo flour (BF), high melted strength polypropylene (HMSPP), polypropylene (PP), 1% modified azodicarbonamide (AC) foaming agent, and maleic anhydride grafted polypropylene (MAPP) coupling agent blends were prepared by injection molding. The composites with different BF contents of 0, 20%, 33% and 42% were exposed to accelerated cycling of water immersion followed by freeze thaw at the temperature of -40-60℃ for 0, 3, 6, and 9 cycles. The effects of freeze-thaw cycles accelerated weathering on the color change and the physico-mechanical properties and thermal behavior of the foamed composites were investigated. The surfaces morphology of composites non-weathered and freeze-thaw cycles weathered were investigated by (Environmental Scanning Electronic Microscopy, ESEM) and the chemical structures were also analyzed by FTIR. The results showed that the composites at higher BF content exhibited greater color change and larger decreases in physico-mechanical properties especially the tensile and impact strengths as compared to the one without weathering. The negative effects of the weathering increased with the growing number of freeze-thaw cycles. The color changeΔE* of 0, 20%, 33%, and 42% BF/PP composites after nine times freeze-thaw cycles were 0.9, 2.4, 7.0, and 9.9, respectively. The corresponding lightness changeΔL*, redness changeΔa*, and yellowness changeΔb*of 42% BF/PP composite were 8.7, 1.3, and 4.7, respectively. The retentions of flexural modulus, and bending, tensile, and notched impact strengths of 0%, 20%, 33%, and 42% BF/PP composites were 95.2% - 99.1%, 97.3% - 98.9%, 94.9% - 97.5%, and 92.0% - 95.6%, respectively. The freeze-thaw cycles slightly affected the thermal behavior of composites as the initial temperature of thermal decomposition (Ti) for the 0% and 33% BF/PP foamed composite after nine times freeze-thaw cycles reduced by 19℃ and 8℃, respectively. ESEM observation revealed that the surfaces of freeze-thaw cycles weathered composites were no longer smooth; and the micro cracks and folds appeared; meanwhile, some parts of the polymers layers dropped off. FTIR analysis indicated that the wood index (the ratio of the peak intensity at 2 912 cm-1 and the peak intensity at 1 023 cm-1) reduced and the bamboo particles of the composites surfaces lost and the intensity of the groups for PP decreased due to the freeze-thaw cycles weathering.
