Hybrid polymer networks of unsaturated polyester–urethane as composite matrices for jute reinforcement

Abstract

Reactions of unsaturated polyester resin and 4,4 0 diphenyl methane diisocyanate were carried out at different NCO/OH ratios in presence of catalysts to form the hybrid polymer networks. Chain extender (1,4 butanediol) added in the hybrid network (NCO/OH ratio: 0.76) was optimized at a level of $ 3 wt % only of the polyester resin. The curing of these networks was studied by a rigid body pendulum type (RPT) method in terms of reduced damping ratio and increased frequency. Lack of multiple glass transition temperatures, sharp Tan delta peak, and particulate composite type morphology clearly demonstrated the formation of phase mixed domains in the hybrid networks. The storage modulus and loss modulus master curves obtained by dynamic mechanical analysis indicate that hybrid polymer networks retained higher modulus at lower and intermediate frequencies over the polyester resin showing their superior time-dependent response. Efficacy of these hybrid network resins was examined as matrices in the jute composites and compared with those of polyester resin and unsaturated polyester-polyurethane interpenetrating network matrices. It is found that the hybrid polymer network matrix composites exhibited superior physicomechanical properties under both dry and boiling water age test. Fractographic evidences such as fiber-matrix adhesion, hackle markings, and fiber breakage also supported their superior behavior over other composite matrices.

Influence of Aluminum Hydroxide Particles on the Properties of Modified Unsaturated Polyester

“…不饱和聚酯因价格低廉、加工容易和应用灵活 [1][2][3] ，而备受关注的一类工业化热固性树脂，它可应用 于片材、建筑材料、粘胶剂、涂料，且在建筑行业和 电子工业也发挥着重要作用 [4][5][6] 。 通常不饱和聚酯是由 二元醇、马来酸酐和其它二元酸缩聚反应制备而成， 合成方法灵活，原料来源广 [7][8][9] 。尽管不饱和聚酯拥有 众多优点，可室温储存、室温固化、低密度、材料透 明和绝缘 [10] ；但传统不饱和聚酯也存在某些缺点，相 应材料通常强度不高、韧性差、耐酸碱老化性差、易 燃 [11] 。大量文献报道，通过两种方法可改善传统不饱 和聚酯材料的性能。方法一：通过化学合成方法，在 不饱和聚酯分子链引入特殊基团，提高相应材料力学 性能或耐酸、碱老化性。在不饱和聚酯分子链结构上， 通过化学共价键引入丙烯酸酯基团 [12] 或双环戊二烯 结构 [13] 氢氧化铝颗粒对改性不饱和聚酯性能的影响 填充无机填料或化学助剂。适量的纳米二氧化硅、蒙 脱土和短丝纤维提高了不饱和聚酯的力学及热稳定 性 [14][15][16][17][18] …”

Mechanical properties of jute fiber–reinforced UP/PU hybrid network composites

“…The use of unsaturated polyester (UP) resins has been widely employed as matrices for producing jute composites in low-cost housing applications such as panels, profiles, doors, roofing sheets, and so on. 1 –6 However, the ability of these jute composites to retain long-term properties is unfortunately offset by their dimensional instability due to the high water absorption of jute 7 –9 and delamination due to poor toughness behavior of the UP resins. 10,11 It is known that UP resins are usually brittle and exhibits 5–7% volume shrinkage during curing.…”

Optimization of Thermal and Mechanical Properties of Unsaturated Polyester Resin as a Binder in Polymer Concrete for Manufacturing Precision Tool Machine Bases

“…Copolymers of UPE and polyurethanes [24,25], polyureas, polysiloxanes, polyimides or polyglycols also produce resins with improved damping properties [26]. Butadiene as a vinyl monomer has also been employed to modify UPE resin's mechanical properties [27].…”