硼酸铝纳米晶须增强聚羟基脂肪酸酯的研究

Improving mechanical property of polyhydroxyalkanoate composites using Al_(18)B_4O_(33) nanowhiskers

为了提高生物降解材料聚羟基脂肪酸酯（PHA）的机械性能,利用具有高强度的硼酸铝纳米晶须作为增强体,制备成复合材料。采用溶胶凝胶法制备出直径为20~50 nm,长度约为1 mm的Al（18）B4O（33）纳米晶须。纳米晶须增强了PHA复合材料的机械性能,实验结果表明：在添加量为0.4%时达到最大抗拉强度为38.5 MPa,增大了109%;抗屈服强度提高到26.2 MPa,提高了将近三倍;断裂伸长率提高了24.5%;复合材料的杨氏模量最大为7.6 MPa,提高了四倍多。说明Al（18）B4O（33）纳米晶须的添加既可以改善PHA的韧性又提高的材料的刚性。另外,断裂面表明Al（18）B4O（33）纳米晶须和PHA有较好的结合力。复合材料中PHA主要是保护Al（18）B4O（33）纳米晶须不与外界直接接触,固定Al（18）B4O（33）纳米晶须的位置,当材料受到外力时将载荷传递和分散给Al（18）B4O（33）纳米晶须,而Al（18）B4O（33）纳米晶须承受主要的力,从而提高了材料的性能。

In order to improve the mechanical property of Polyhydroxyalkanoate（PHA）biodegradable, the high strength aluminum nanometer borate （Al18B4O33） nanowhiskers was chosen as strengthen materials and compounded. The Al18B4O33 nanowhiskers were synthesized via a sol-gel and diameter and lengthare about 20-50 nm and 1μm, respectively. The mechanical property of PHA composite was improved byadding the Al18B4O33nanowhiskers. When the composition of Al18B4O33 nanowhiskerswas 0.4%, ultimate tensile strength was 38.5 MPa, increased by 109%; the yield strength increased to 26.2 MPa, improved nearly three times; the elongation to break statistics increased by 24.5% and the Young＇s modulus was 7.6 MPa, improved more than four times. It indicates that the Al18B4O33 nanowhiskers can not only increase the toughness but also improve the rigid of the PHA polymers. Additionally, the fracture surface of the composite suggests the binding force between Al18B4O33 nanowhiskers and PHA. The PHA made Al18B4O33nanowhiskers uncontacted with outside and fixed the position. When the compositesbear external load, the PHA transfersit to Al18B4O33 nanowhiskers, which bear most of the external load, so the property of composites was improved.