聚氨酯丙烯酸酯轮胎的3D打印成型及性能研究

为了实现新型非充气式轮胎的绿色制造,制备了一种新型、具有软硬段结构的聚氨酯丙烯酸酯树脂,借助3D打印技术实现了蜂窝状聚氨酯丙烯酸酯轮胎的制造并分析了其基本力学性能。结果表明,利用不同多元醇为扩链剂和甲基丙烯酸羟乙酯为封端剂制备的聚氨酯丙烯酸酯树脂分子质量和性能可控,其中以丙三醇为扩链剂制备的聚氨酯丙烯酸酯树脂性能最佳。随着多元醇官能度的升高硬段结构增多,其拉伸强度从7.23 MPa增强至36.19 MPa,断裂伸长率从448%降至39.42%。此外,3D打印的聚氨酯丙烯酸酯蜂窝状轮胎比传统轮胎减重44.7%,且具有良好的亲水性。

Influence of processing parameters and heat treatment on phase composition and microstructure of plasma sprayed hydroxyapatite coatings

Air plasma spraying process was employed to fabricate various hydroxyapatite(HA)coatings on titanium substrates.The influence of processing parameters on the phase composition and the microstructure of the obtained coatings was investigated.The effect of heat treatment on as-sprayed coating in terms of the crystallinity and microstructure was also studied.The phase composition of coatings was analyzed by X-ray diffraction(XRD)and FTIR.The surface and cross-section morphologies and microstructure of coatings as well as the morphology of feedstock were evaluated using scanning electron microscope(SEM).The crystallization temperature of amorphous HA phase in as-sprayed coating was examined by using differential thermal analysis(DTA). The results suggest that phase composition and microstructure of as-sprayed HA coatings strongly depend on the spraying parameters,and heat treatment at 760 ℃for 2 h is one of effective means for increasing the crystallinity and improvement in microstructure of as-sprayed HA coatings.