This paper deals with a study on toughening of an unsaturated polyester resin (UPR) using maleimide end-capped oligomers of polypropylene glycol (M-PPG), polytetramethyene oxide (M-PTMO), and polyethylene glycol (M-PEG) of varying molecular weights. These macro bismaleimides with large spacing between the functional groups were synthesized from the corresponding polyols (hydroxy telechelics) by reaction with (4-Maleimido) benzoyl chloride (MBC). These derivatives were characterised by chemical and spectral methods. These were then blended and co-cured with a UP resin based on copoly-propylene glycol (terephthalate –maleate) and relying on maleic acid–styrene copolymerisation for curing. The impacts of the nature, concentration and molecular weight of the telechelic additive on the physical and mechanical properties of the resultant unsaturated polyester resin (UPR) blends have been examined. Addition of the telechelics improved the mechanical characteristics of the crosslinked systems significantly. The improvement in fracture properties for a telecheilc was directly correlatable to a decrease in overall crosslink density estimated exprimentally as well as theoretically. The additive’s backbone structure dictated the Tg and related properties of the blend. The properties were found to be the best for the blend toughened with M-PPG with a molecular weight 2000 g/mol, at 2.5 parts per hundred parts.The morphological features at this concentration as reflected in scanning electron microscopic analyses showed descrete poly ether particles microphase separation in the UPR matrix that acted as a crack path arrester.

本文研究了使用不饱和聚酯聚丙烯酸酯（M-PPG），聚四甲基环氧乙烷（M-PTMO）和可变分子聚乙二醇（M-PEG）的马来酰亚胺封端低聚物增韧不饱和聚酯树脂（UPR）的研究重量。通过与（4-马来酰亚胺基）苯甲酰氯（MBC）反应，由相应的多元醇（羟基远螯剂）合成这些官能团之间具有大间隔的大双马来酰亚胺。这些衍生物通过化学和光谱方法表征。然后将它们混合并与基于共聚丙二醇（对苯二甲酸酯-马来酸酯）的UP树脂共固化，并依靠马来酸-苯乙烯共聚进行固化。大自然的影响 已经研究了远螯添加剂的浓度和分子量对所得不饱和聚酯树脂（UPR）共混物的物理和机械性能的影响。远螯剂的加入大大改善了交联体系的机械特性。Telecheilc断裂性能的改善与实验和理论估算的总交联密度的降低直接相关。添加剂的主链结构决定了共混物的Tg和相关性能。发现该特性对于分子量为2000克/摩尔，每100份2.5份的M-PPG增韧的共混物是最好的。