A polyvinyl acetal poly(vinyl acetal), such as polyvinyl butyral, resin formulation, a method of extruding poly(vinyl acetal) resins, and related materials and products that provide for monolithic poly(vinyl acetal) sheets and glass panes having high Tg of at least 50° C. and high modulus at acceptable rates as indicated by their high melt flow index. This is made possible by a reduction in the amount of plasticizer while using a low molecular weight resin not to exceed 160,000 to obtain a thermoplastic resin having a high melt flow index and high Tg. The articles made with these monolithic interlayer sheets can be used in applications that require good modulus at outdoor temperatures.