用于无磷洗涤助剂的可生物降解共聚物P(AA-co-MDO)的合成及表征

合成了一种环状乙烯酮缩二醇化合物2-亚甲基-l,3-二氧环庚烷(MDO)单体,并通过与部分中和的丙烯酸(AA)进行自由基开环聚合,合成了主链上含有酯基、侧链上含有羧基的新型可生物降解共聚物P(AA-co-MDO),用傅里叶变换红外(FTIR),核磁共振(1H-NMR)和多角度激光光散射(MALLS)对共聚物的组成与分子量进行了表征,结果表明,共聚物结构明确.同时,通过差示扫描量热法(DSC)和热重分析法(TGA)测定了共聚物的热性能,结果显示,P(AA-co-MDO)有明显的玻璃化转变温度(Tg).研究发现,随着MDO投料量的增加,热稳定性有所下降,但仍维持在较高的水平,完全可以满足洗涤剂的生产工艺要求.X-射线衍射(XRD)测定结果显示,P(AA-co-MDO)为无定型聚合物,有利于生物降解,并通过共聚物在活性污泥的降解实验表明,其降解率随体系中MDO含量的增加而升高.另外,对共聚物的助洗性能进行了测定,并与其他助洗剂进行了对比,结果表明,其螯合能力强、分散力高、pH缓冲值高,是一种性能优良的洗涤助剂.

SYNTHESIS AND CHARACTERIZATION OF BIODEGRADABLE COPOLYMERS AS NON-PHOSPHOROUS DETERGENT BUILDERS

A cyclic ketene acetal of 2-methylene-1,3-dioxepane(MDO) was prepared and undergone free-radical ring-opening polymerization with acrylic acid(AA) to produce biodegradable copolymers P(AA-co-MDO) which had ester groups in the backbone and carboxyl as pendant functional groups.The structures and weight-average molecular weights(Mw) were characterized by Flourier transform infrared spectroscopy(FTIR),nuclear magnetic resonance(1H-NMR) and multi-angle laser light scattering measurements(MALLS).Obvious changes of molecular weight could not be observed when the ratio of MDO to AA was varied.The thermal property of the copolymers was investigated by differential scanning calorimetry and termogravimetric analysis.It was found that the copolymers showed evident glass transition temperature.The thermostability of the copolymers declined as the MDO content increased,but still maintained at a high level to meet the requirement of production process of detergent builders.The X-ray diffraction results indicated that P(AA-co-MDO) copolymers were amorphous and these copolymers may have good biodegradable performance.The degradation experiments of copolymers in activated sludge revealed that the more MDO content was in copolymer,the faster degradation rate of the copolymer was.The performance of the copolymers and other detergent builders was studied and the results showed that the copolymers possessed high chelating capacity,good dispersancy and favorable pH buffer ability,and therefore were ideal detergent builders.